CA2089225C - Method and apparatus for modulated differential analysis - Google Patents

Method and apparatus for modulated differential analysis

Info

Publication number
CA2089225C
CA2089225C CA002089225A CA2089225A CA2089225C CA 2089225 C CA2089225 C CA 2089225C CA 002089225 A CA002089225 A CA 002089225A CA 2089225 A CA2089225 A CA 2089225A CA 2089225 C CA2089225 C CA 2089225C
Authority
CA
Canada
Prior art keywords
sample
differential
modulation
heat flow
temperature
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
CA002089225A
Other languages
French (fr)
Other versions
CA2089225A1 (en
Inventor
Michael Reading
Brian K. Hahn
Benjamin S. Crowe
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
TA Instruments Inc
Original Assignee
TA Instruments Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Family has litigation
First worldwide family litigation filed litigation Critical https://patents.darts-ip.com/?family=25292741&utm_source=google_patent&utm_medium=platform_link&utm_campaign=public_patent_search&patent=CA2089225(C) "Global patent litigation dataset” by Darts-ip is licensed under a Creative Commons Attribution 4.0 International License.
Application filed by TA Instruments Inc filed Critical TA Instruments Inc
Publication of CA2089225A1 publication Critical patent/CA2089225A1/en
Application granted granted Critical
Publication of CA2089225C publication Critical patent/CA2089225C/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N25/00—Investigating or analyzing materials by the use of thermal means
    • G01N25/18—Investigating or analyzing materials by the use of thermal means by investigating thermal conductivity
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N25/00—Investigating or analyzing materials by the use of thermal means
    • G01N25/20—Investigating or analyzing materials by the use of thermal means by investigating the development of heat, i.e. calorimetry, e.g. by measuring specific heat, by measuring thermal conductivity
    • G01N25/48—Investigating or analyzing materials by the use of thermal means by investigating the development of heat, i.e. calorimetry, e.g. by measuring specific heat, by measuring thermal conductivity on solution, sorption, or a chemical reaction not involving combustion or catalytic oxidation
    • G01N25/4806—Details not adapted to a particular type of sample
    • G01N25/4826—Details not adapted to a particular type of sample concerning the heating or cooling arrangements
    • G01N25/4833—Details not adapted to a particular type of sample concerning the heating or cooling arrangements specially adapted for temperature scanning
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N25/00—Investigating or analyzing materials by the use of thermal means
    • G01N25/20—Investigating or analyzing materials by the use of thermal means by investigating the development of heat, i.e. calorimetry, e.g. by measuring specific heat, by measuring thermal conductivity
    • G01N25/48—Investigating or analyzing materials by the use of thermal means by investigating the development of heat, i.e. calorimetry, e.g. by measuring specific heat, by measuring thermal conductivity on solution, sorption, or a chemical reaction not involving combustion or catalytic oxidation
    • G01N25/4846—Investigating or analyzing materials by the use of thermal means by investigating the development of heat, i.e. calorimetry, e.g. by measuring specific heat, by measuring thermal conductivity on solution, sorption, or a chemical reaction not involving combustion or catalytic oxidation for a motionless, e.g. solid sample
    • G01N25/4866—Investigating or analyzing materials by the use of thermal means by investigating the development of heat, i.e. calorimetry, e.g. by measuring specific heat, by measuring thermal conductivity on solution, sorption, or a chemical reaction not involving combustion or catalytic oxidation for a motionless, e.g. solid sample by using a differential method

Abstract

The present invention relates to differential analytical techniques for determining the composition, phase, structure, identification or other properties of a material that undergoes a transition as function of a driving variable.
As applied to differential scanning calorimetric analysis (DSC), the preferred embodiment comprises: (1) heating a sample of the material with a linear temperature ramp that is modulated with a sinusoidal heating rate oscillation; and (2) deconvoluting the resultant heat flow signal into rapidly reversible and non-rapidly reversible components.

Description

208922~

~OUND

Field of the Invention.
The present invention relates to differential analytical techniques for determining the composition, phase, structure, or other properties of a sample of material.

Background of the Invention.
Thermal analysis techniques generally comprise measuring a physical parameter as a function of the temperature of the sample. The sample temperature is strictly controlled throughout the analysis. Whenever the sample undergoes a chemical transformation, a physical transformation, a phase change or another transition which affects the physical parameter being measured, the changes in that physical parameter may be interpreted to analyze the composition, structure, or thermal stability of the sample.
In differential thermal analysis techniques, the physical parameter of the sample being measured is compared to that of a reference, as a function of the temperature of the sample. The difference in the physical parameter measured for the sample and that measured for the reference is then recorded. The differential thermal analysis technique compensates for the effects of heating rate and ambient conditions that could cause changes in the measured physical parameter of the sample and reference. The differential thermal analysis technique can increase the sensitivity of the measurement of the physical parameter by removing large offsets in the value of the physical parameter whenever the precision of the measuring apparatus is limited.

, ~ 2089225 One common thermal analysis technique is Differential S~nni ng Calorimetry (DSC). DSC is a thermal analysis technique which measures the temperatures and heat flow associated with chemical or physical transitions in materials as a function of time and temperature. The classical DSC method comprises heating the sample material and the reference material at a constant rate of temperature increase, typically 5 C to 20 C per minute, and recording the difference in heat flow into or out of the sample and the reference as a function of temperature.
Other differential thermal analysis techniques include Pressure Differential Scanning Calorimetry (PDSC), Differential Thermal Analysis (DTA), Pressure Differential Thermal Analysis (PDTA), Differential Photocalorimetry (DPC), pressure Differential Photocalorimetry (PDPC), Differential Thermogravimetry (DTG), and Pressure Differential Thermogravimetry (PDTG).
Furthermore, the present invention applies to all differential analysis techniques. It is not limited to dif-ferential thermal techniques. Whereas thermal differential analysis techniques depend upon temperature as the driving variable, non-thermal differential analysis techniques depend upon another driving variable, such as pressure, applied stress, or wavelength of incident radiation.

~\ 2~8922S
DSC measurements provide quantitative and qualitative information about the sample transitions that involve endothermic or exothermic processes, or changes in heat capacity. Pressure DSC is a related technique in which the heat flow and temperature of transitions are measured as a function of temperature under controlled pressure, or as a function of pressure under controlled temperature.
Differential Thermal Analysis, like DSC, measures the temperatures and heat flow associated with transitions in materials as a function of time and temperature. However, unlike DSC, DTA results are semi-quantitative. Pressure DTA
is a related technique in which the heat flow and temperature of transitions are measured as a function of temperature under controlled pressure, or as a function of pressure under con-trolled temperature. DTA is generally carried out at higher temperatures than DSC.
Differential Photocalorimetry measures the heat absorbed or released by a sample as it and a reference are exposed simultaneously to radiation of known wavelength and intensity. Pressure DPC is a related technique in which the heat absorbed or released by the sample is measured as a function of temperature under controlled pressure, or as a function of pressure under controlled temperature.
Differential Thermogravimetry measures the differential weight change of a sample and a reference as a function of time and temperature. Pressure DTG is a related technique in which the differential weight change is measured _ 208q225 as a function of temperature under controlled pressure, or as a function of pressure under controlled temperature.

High resolution analytical techniques are described in U.S. Patent No. 5,165,792, dated November 24, 1992 and commonly assigned with the present application. Those techniques seek to improve the resolution of changes in a characterizing physical parameter by controlling the rate of sample heating during transitions as a function of the rate of change of the physical parameter. When non-differential thermal analysis techniques are used, the high resolution techniques are effective in improving resolution for many transitions. However, they usually reduce the sensitivity of transitions when applied to differential thermal analysis techniques. This is because, for most differential thermal analysis techniques, the magnitude of the differential physical parameter is a direct function of the heating rate.
Reducing the heating rate during transitions causes the differential signal to change, which may alter or obscure the true differential signal resulting from the transition event. This obscuring of the physical parameter can reduce the utility of the high resolution techniques when applied to conventional differential thermal analysis techniques.

Conventional differential thermal analysis techniques are limited in their ability to separate non-reversible events caused by enthalpic processes (chemicalor physical) from reversible events such as changes in the heat capacity of the sample. This is because the reversible and non-reversible processes often occur simultaneously, or occur severely overlapped in time and/or temperature.
In addition, conventional and high resolution thermal analysis techniques cannot distinguish between rapidly reversible and non-rapidly reversible transitions within a single heating or cooling scan of the sample.

D~l~l lONS
"Transition" or "Transformation", as used herein, mean any type of physical or chemical transformation, phase change, or structural change in a material.
"Analyzing", as used herein with respect to materials, means determining the composition, phase, structure, and/or identification of the material.
"Driving variable", as used herein, means the independent physical parameter, such as temperature, pressure, applied stress, or wavelength of incident radiation, that is being used to drive a material through a transition. For example, in thermal analysis techniques such as DSC, temperature is typically the driving variable.
"Characterizing differential physical parameter", as used herein, means the dependent differential physical parameter characterizing the sample, such as its heat flow, weight change, or change in dielectric or mechanical properties.
"Rapidly reversible", as used herein, means any portion of a signal, transition, or event which is a direct 2~8g225 .

function of the rate of change of the driving variable. For example, the contribution to the heat flow signal in DSC
attributable to the rate of change of temperature of the sample material is a rapidly reversible transition. In DSC, for example, one of the contributions to the rapidly reversible portion of the heat flow signal is the heat capacity of the sample material. Rapidly reversible processes include those processes which are thermodynamically reversible and can occur rapidly relative to the rate of change of the driving variable.
"Non-rapidly reversible", as used herein, means any portion of a signal, transition or event which is a direct function of the value of the driving variable. For example, the contribution to the heat flow signal in DSC attributable to the absolute temperature of the sample material is a non-rapidly reversible transition. This might be caused by a chemical or physical change taking place such as recrystallization. Non-rapidly reversible processes include those processes which are thermodynamically irreversible, as well as processes which are thermodynamically reversible, but which reverse very slowly relative to the rate of change of the driving variable due to the kinetic limitations of the process.
"Deconvolution", as used herein, means the process of separating the dependence of a characterizing physical parameter on a driving variable into two or more component parts so that the component parts can be utilized or analyzed ~08922~

separately, or compared with each other. For example, the dependence of a characterizing physical parameter can be deconvoluted into rapidly reversible and non-rapidly reversible components.
"Signal baseline", as used herein, means that portion of a signal representing the value of a characterizing physical parameter obtained in a range in which there are no transitions or transformations.
"Sensitivity" of an analytical technique, as used herein, means the degree to which signals associated with transitions can be physically distinguished from the signal baseline in the analytical data produced by the technique.
This quality of the analytical technique is most critical when the value of the driving variable is changing very slowly.
"Resolution" of an analytical technique, as used herein, means the degree to which signals associated with different transitions can be physically separated in the analytical data produced by the technique. This quality of the analytical technique is most critical when multiple transitions occur at closely spaced values of the driving variable.
"Moving averaged", is a data smoothing technique that can be applied to data collected as discrete data points at uniform increments, comprising averaging the raw data over a window of n data points to obtain a single smoothed data point, incrementing the window by one data point, and repeating the process until all the data has been averaged.

208~2~

Thus the first n raw data points, data points i = 1, . . . n, are averaged to calculate the first smoothed data point, data points i = 2, . . . n+1, are averaged to produce the second data point, etc.
A "pulse wave" is a wave of spikes or impulse functions occurring at regular intervals. As applied to thermal analysis techn;ques, a pulse wave could be produced by bursts of instantaneous energy, e.g., from a laser, at regular intervals. The key characteristic of a pulse wave is that the duration of the energy burst is short compared to the duration of its effect.
SUMMARY OF THE l~V~ lON
In modulated DSC (MDSC), a rapid heating rate oscil-lation is added to a conventional linear temperature ramp. If the heating rate oscillation has low amplitude but high frequency then it is possible to obtain a relatively high instantaneous heating rate even though the underlying heating rate is comparatively low.
The present invention uses a computer system to control a differential thermal analytical technique by monitoring and modulating the technique's driving variable and deconvoluting a resultant characterizing differential physical parameter into rapidly reversible and non-rapidly reversible contributions.
For example, when the analytical technique is DSC, the driving variable is temperature and the characterizing 20~2~
.

differential physical parameter is heat flow. The response of the calorimeter to the sample can be expressed as follows:
dQ/dt = - dT/dt * fr(t,T) + fn(t~T) (1) Where dQ/dt = heat flow out of the sample (Joules/sec) dT/dt = heating rate (C/sec) t = time (seconds) T = temperature (C) fr(t,T) = rapidly reversible contribution (Joules/C) fn(t,T) = non-rapidly reversible contribution (Joules/sec) fr(t,T) and fn(t,T) are functions of time and temperature derived by deconvolution of the analytical data.
This equation separates the DSC differential heat flow into a rapidly reversible portion, fr(t,T), which is dependent on heating rate, and a non-rapidly reversible portion, fn(t,T), which is not dependent on heating rate.
The modulated DSC heat flow signal will contain a heat flow oscillation which will be to some degree out of phase with the heatinq rate oscillation. The modulated DSC
heat flow signal can be deconvoluted to separate the rapidly reversible, fr(t,T) and non-rapidly reversible, fn(t,T), heat flow contributions, as shown in equation (1).
Deconvolution of the modulated DSC heat flow and temperature data into parameters other than the ones described above is also possible. For example, the modulated heat flow and temperature data could be deconvoluted to derive direct _ g .

kinetic information about the sample, such as its reaction rate and activation energy.
Other useful properties which could be deconvoluted include the heat capacity of the sample and the phase shift between the modulated sample heating rate and the resultant heat flow.
The modulated DSC technique can be further extended to automatically or manually vary the modulation frequency and/or amplitude during the DSC scan so as to obtain data at multiple frequencies, amplitudes and temperatures during a single heating or cooling scan. This can be accomplished by applying modulation cycles of specific frequencies, or by com-bining a plurality of frequencies into each modulation cycle and deconvoluting the frequency information along with the characterizing physical parameters. This scanning MDSC
technique has the advantages of improving the productivity of the analytical laboratory and reducing the environmental-and-operator-related variations in multiple sample runs. As a further extension, the deconvolution process could be coupled with frequency and/or amplitude selection to enable frequency/amplitude optimization for specific parameter values or sample conditions.
A major advantage of modulated DSC is the ability to use DSC to separately measure and study rapidly reversible and non-rapidly reversible events which are overlapped in temperature and time. For example, in polymer chemistry, it is common for a non-enthalpic event, such as a change in heat .

capacity due to a glass transition, to occur at the same temperature as an enthalpic event, such as a recrystallization. When these temperature-overlapped events are studied with conventional DSC, the resultant heat flow contributions from each event are additive and therefore obscure each other. When the modulated DSC technique is used to analyze such a sample, the resultant heat flow signal can be deconvoluted into rapidly reversible and non-rapidly reversible signals corresponding to the glass transition and recrystallization events respectively.
A second major advantage of modulated DSC is the ability to use variable heating rate DSC techniques, termed Controlled-Rate or Constrained-Rate DSC, to reduce the underlying heating rate of the DSC scan during transitions in order to improve resolution, without a resultant loss in DSC
sensitivity. In the Controlled-Rate DSC case, the heat flow signals are measured in Joules/C instead of the conventional Joules/sec, thereby removing the dependency on heating rate and the resultant reduction in signal magnitude at low heating rates.
Another advantage of modulated DSC is an improved ability to study the kinetic properties of chemical reactions with respect to temperature. For a given modulation frequency and amplitude, the ratio of the rapidly reversible component of the heat flow to the non-rapidly reversible component is directly related to the kinetic rates of the forward and reverse reactions of the sample material at the measurement .

temperature. Reactions which are overlapped in temperature but have different rates of reaction can be separated into rapidly reversible and non-rapidly reversible components by appropriate adjustment of the modulation frequency and amplitude.
A first object of the present invention is to provide a method for controlling the driving variable in differential analysis techniques to substantially improve the resolution of transitions through the use of variable rates of change in the driving variable.
A second object of the present invention is to provide a temperature control method for differential thermal analysis techniques which achieves substantially improved resolution of transitions through the use of variable heating rate heating techniques.
A third object of the present invention is to separate the characterizing differential physical parameter into rapidly reversible and non-rapidly reversible components.
A fourth object of the present invention is to provide the analyst with a method of adjusting the amount of separation between rapidly reversible and non-rapidly reversible transitions.
A fifth object of the present invention is to improve the sensitivity of differential analysis techniques.
A sixth object of the present invention is to provide the analyst with an alternate method for studying the kinetic properties of chemical reactions.

208~22~
..
A seventh object of the present invention is to obtain more accurate transition temperatures.
An eighth object of the present invention is to simplify the interpretation of differential thermal analysis data by more sharply defining the temperatures at which transitions occur.
A ninth object of the present invention is to isolate signal changes so that they can be more easily measured, integrated, compared with other results, and interpreted.
These and other objects of the present invention are described in greater detail in the following description of the invention, the appended drawings and the attached claims.

DE8CRIPTION OF THE DRaWINGS
FIGURE la is a block diagram showing how different differential thermal analysis techniques may be used with the present invention.
FIGURE lb is a block diagram of a differential scanning calorimetric apparatus.
FIGURES 2a-2c are DSC scans of Poly(ethyleneterephthalate) (PET) obtained according to the methods described in Example 2.
FIGURES 3a and 3b are DSC scans of Poly(ethylene terephthalate) (PET) obtained according to the methods described in Example 3.

2~8922~

FIGURES 4a and 4b are DSC scans of Poly(ethylene terephthalate) (PET) obtained according to the methods described in Example 4.

DE8CRIPTION OF THE PREFERRED EMBODIMENT OF THE l~v~.llON
The present invention resides in control methods for conventional differential analytical apparatus, and is an improvement on the methods currently practiced to control such conventional differential analytical apparatus.
The following detailed description of the present invention applies specifically to differential scanning calorimetry, in which temperature is the driving variable and heat flow is the characterizing differential physical parameter. However, although the present invention is described as applied to differential sc~n~; ng calorimetric analysis, it should be understood that the present invention could be used with any differential thermal analysis method including Pressure Differential Scanning Calorimetry, Differential Thermal Analysis, Pressure Differential Thermal Analysis, Differential Photocalorimetry, Pressure Differential Photocalorimetry, Differential Thermogravimetry, and Pressure Differential Thermogravimetry, as well as any combination of these techn; ques. The principles and methods described herein with reference to differential scanning calorimetric analysis could be applied to any and all of the thermal analytical methods listed above, as well as to other analytical methods -~ 20g9225 wherein a characterizing differential physical parameter is measured as a function of a driving variable.
Figure la is a schematic representation of the present invention as it may be used with Differential Scanning Calorimetry (DSC) 101, Pressure Differential Scanning Calorimetry (PDSC) 102, Differential Thermal Analysis (DTA) 103, Pressure Differential Thermal Analysis (PDTA) 104, Differential Photocalorimetry (DPC) 105, Pressure Differential Photocalorimetry (PDPC) 106, Differential Thermogravimetry (DTG) 107, Pressure Differential Thermogravimetry (PDTG) 108, digital plotter 109 and personal computer 110.
Figure lb is a schematic representation of a conven-tional differential scanning calorimeter 111 comprising: a sample pan 112; reference pan 113; sample temperature thermo-couple 114; reference temperature thermocouple 115; thermo-electric disc 116; purge gas inlet 117; purge gas outlet 118;
electric furnace 119 comprising silver block heater 120, silver ring 121, silver lid 122, and heater thermocouple 123;
furnace chamber 124; heater controller 125; analog-to-digital converter 126; and microcomputer 127. Figure lb also shows personal computer 110 and digital plotter 109. The differential scanning calorimeter measures the heat flow difference between sample pan 112 and reference pan 113 which are supported by a thermoelectric disc 116 inside a closed furnace chamber 124. The thermoelectric disc 116 serves as the major heat flow path for transferring heat from furnace 119 to sample pan 112 and reference pan 113. The disc is also -~ 208922~
used as a common material of the differential thermocouple for measuring the temperature difference between the sample and reference pans. Microcomputer 127 receives differential temperature and sample temperature from sample thermocouple 114 and reference thermocouple 115 via analog-to-digital converter 126. Microcomputer 127 also controls the temperature of the furnace 119 by controlling the power to the furnace using heater controller 125. In the preferred embodiment of the present invention, the temperature of the furnace is controlled by the microcomputer in accordance with the steps outlined below. However, the present invention can be practiced using any combination of computers, hardware and operator control. Personal computer 110 and digital plotter 109 are used to analyze, store, display and plot the analytical results. A purge gas is usually introduced via the purge gas inlet 117. The purge gas can be a gas that reacts with constituents of the sample being analyzed, or it can be an inert gas, i.e., a gas that does not react with the sample used to prevent reactions with air. Typical purge gases include dry air, oxygen, nitrogen, argon, helium, carbon monoxide and carbon dioxide.
The preferred embodiment of the present invention is outlined below as applied to differential scanning calorimetric analysis. The linear heating rate is modulated at a predetermined frequency and amplitude such that the r~; ~um heating rate obtained during each modulation period is substantially larger than the underlying linear ramp rate, but the total sample temperature excursion during each modulation period is relatively small.
The larger the difference between the m~;mllm heating rate and the underlying rate, the greater will be the resultant sensitivity of the technique. The preferred maximum heating rate is at least twice the underlying heating rate. A
larger heat sinking capacity in the system will improve modulation performance. To this end, a cooling jacket or integral cooling system is desirable.
The smaller the sample temperature excursion during each modulation period, the greater will be the resultant resolution of the technique. A temperature excursion less than 2 C is preferred.
The modulation frequency is selected to produce the desired separation between rapidly reversible and non-rapidly reversible components of the heat flow signal. For thermo-dynamically reversible processes, the higher the modulation frequency, the greater the amount of signal that will deconvolute as non-rapidly reversible and the smaller the amount that will deconvolute as rapidly reversible. Lower modulation frequencies cause the opposite effect.
The sample temperature and differential heat flow resulting from the modulation is stored and analyzed over one full modulation period using a moving deconvolution technique which separates the A/C and D/C components of the heat flow.
These separated components are moving-averaged over one full modulation cycle and reported in terms of the underlying ~ 208~225 heating rate. The separated components are summed to produce the resultant total heat flow at the underlying rate.
The preferred embodiment comprises the following steps:
STEP 1. Selecting an underlying heating rate.
STEP 2. Selecting a modulation frequency.
STEP 3. Selecting a modulation amplitude.
STEP 4. Applying a sinusoidal modulation to the heating rate selected in step 1, at the frequency selected in step 2 and at the amplitude selected in Step 3.
STEP 5. Monitoring the sample temperature.
STEP 6. Monitoring the differential heat flow.
STEP 7. Deconvoluting the sample temperature and differential heat flow into rapidly reversible and non-rapidly reversible components of heat flow.
STEP 8. Combining the rapidly reversible and non-rapidly reversible components of heat flow to construct the total heat flow at the underlying heating rate.
The present invention can be practiced using any applicable deconvolution technique to separate the rapidly reversible and non-rapidly reversible components of the measured heat flow. In the preferred embodiment, a discrete differential Fourier transform (DFT) technique was used to deconvolute the modulated DSC sample temperature and heat 208~22~

flow. The discrete Fourier transform algorithm for deconvoluting the sample temperature and differential heat flow into rapidly reversible and non-rapidly reversible components of heat flow (step 7 of the preferred embodiment of the current invention) comprises the following substeps:
SUBSTEP 7-1. Calculating the D/C component of the modulated temperature and heat flow signals. The D/C component of each signal is calculated as the unweighted moving average of the signal over one or more full modulation periods. This moving average is the D/C value for the central point in the average.
SUBSTEP 7-2~ Calculating the A/C component of the modulated temperature and heat flow signals. The A/C component of each signal is calculated as a point-by-point subtraction of the D/C
component, calculated in substep 7-1, - from the modulated signal.
SUBSTEP 7-3. Correlating the A/C component of the modulated temperature and heat flow signals with the sinusoidal modulation. The A/C component of each signal is correlated with the modulation signal by multiplying the 208922~

signal by an in-phase sinusoidal signal (cosine) and 90 degree out-of-phase sinusoidal signal (sine), with the same period as the modulation. The sine and cosine products are summed over one or more full modulation periods. These sums are calculated for each successive point in the modulated temperature and heat flow signals.
UBSTEP 7-4. Calculating the A/C amplitude and phase of the modulated temperature and heat flow signals. The A/C
amplitude of each signal is calculated by taking the square root of the sum of the squares of the sine and cosine sums from substep 7-3.
The phase shift of each signal is calculated by taking the arctangent of the ratio of the sine and cosine sums calculated in substep 7-3.
UBSTEP 7-5. Smoothing the amplitude and phase signals. The amplitude and phase signals are smoothed with an unweighted moving average over one or more complete modulation periods.

SUBSTEP 7-6. Calculating the rapidly reversible coefficient. The coefficient for the rapidly reversible component, fr(T,t), is calculated by dividing the A/C
amplitude of the heat flow by 2~fAT, where f is the modulation frequency and AT is the A/C amplitude of the temperature.

SUBSTEP 7-7. Calculating the rapidly reversible component. The rapidly reversible component is calculated by multiplying the rapidly reversible coefficient by the underlying heating rate.

SUBSTEP 7-8. Calculating the non-rapidly reversible component. The non-rapidly reversible component is calculated by subtracting the rapidly reversible component from the D/C
heat flow signal from substep 7-1.

Deconvolution and fitting techniques that may be used to implement the present invention are described in Numerical Recipes, The Art of Scientific Computinq, by W.H. Press, B.P. Flannery, S.A. Teukolsky and W.T.
Vetterling (Cambridge University Press, New York, 1986).
Chapter 12, page 401, describes a Fast Sine and Cosine Transform technique that is somewhat 20892~5 similar to the DFT deconvolution described above.
Chapter 14, page 515, "Singular Value Decomposition", and page 523, "Levenberg-Marquardt Method", describe fitting techni~ues that have been successfully used with the present invention.

Techniques other than the ones discussed above may be used to deconvolute the heat flow into rapidly reversible and non-rapidly reversible portions. Physical characterizing parameters, other than those described above, may also be deconvoluted for report generation and/or control of the DSC module, or for other downstream uses.

The present invention can be further enhanced by using variable heating rate techniques, as described, for example, in U.S. Patent No. 5,165,792 to reduce the underlying heating rate during transitions thereby improving the resolution, without sacrificing the sensitivity of the heat flow measurement.

The present invention can also be applied to chemical or physical transformations that occur upon cooling as well as upon heating, or upon any combination of heating and cooling cycles, whether or not separated by constant temperature periods or constant-rate heating or cooling periods. When the technique is used to analyze materials that undergo transitions upon cooling, the methods described above are still applied, but with the sample cooling rate substituted for the sample heating rate, and with a cooling apparatus substituted for or used in conjunction with the furnace. The present invention applies equally well to ` 208922~

modulation of a cooling system, in which a cold sink (heat source) works with a modulated cooling device, or a combination of modulated heating and modulated cooling.
The sample could be heated or cooled using hot or cold air, lasers, fluid baths, microwave energy, chemical reactions, or other appropriate heating or cooling t~chn;ques.
The preferred embodiment of the present invention, as described above, controls the heating rate of the furnace.
However, the present invention could be practiced by controlling the heating rate of the sample, or by controlling the sample temperature itself instead of by controlling the heating rate.

DESCRIPTION OF ~Uk n~K BMBODIMENTS OF THE lr.v~;~ lON
The present invention may be implemented using a modulation wave shape other than a sine wave. In particular, a square wave, sawtooth wave, triangular wave, pulse wave, or any applicable polynomial wave, or combination of waves, whether symmetric or not, may be used. The modulation wave must be a periodic wave if the discrete Fourier transform deconvolution method, described above, is to be used.
The present invention may also be implemented using deconvolution techniques and discrimination criteria other than a discrete Fourier transform and heating rate, respectively. In particular, the deconvolution may be performed by fitting the data to an appropriate mathematical function, by comparing the data to a data base or library of 208~22~

known results, or by solving systems of simultaneous equations that describe the data.
The present invention may also be implemented with or without deconvolution of the data. Any deconvolution performed may be done in real-time or as post-processing of the data.
The present invention may also be implemented using hardware, software, or a combination of hardware and software.
For example, the heating rate may be modulated by adjusting the physical characteristics of the furnace or cooling system, or by programming a computer that controls the furnace or cooling system heating rate. Analog devices such as amplifiers could be used for multiplication, integrators for summation, inverters for subtraction, and comparators for decision-making.
The present invention may be implemented on a system employing a technique simultaneous with DSC or DTA. For example, on a simultaneous TGA/DTA system.
The present invention may also be implemented on a ~~
system employing an automatic loading and/or unloading apparatus, or automatic heating rate, frequency and/or amplitude adjustment between experiments or heating/cooling cycles. For example, the present invention may be implemented on a robotic sample changing system with preprogrammed experimental parameters for each sample. Alternately, a computer may be used to determine the appropriate adjustments to the heating rate, the modulation fre~uency and/or amplitude `` `` ` 2089225 for one experiment, based upon the results of a previous experiment.
The following examples are provided to illustrate certain embodiments of the present invention. They are not to be construed as limiting the invention in any way.
EXAMPLE 1: DIFFERENTIAL SCANNING CALORIMETRIC ANALYSIS
This example describes the experimental apparatus and procedures used in Examples 2-4. The DSC system used for these analyses was the TA Instruments DSC 2910 Differential Scanning Calorimeter connected to the TA Instruments Thermal Analyst 2100 computer/thermal analyzer. All samples used in the experiments were readily available commercial products. Sample sizes varied from 4.45 to 5.1 milligrams of material. The samples were loaded into standard aluminum DSC sample pans with crimped aluminum lids. The purge gas used was nitrogen (99.998~ pure). The DSC was set up and leveled on a solid non-vibrating work surface.
Before operation of the DSC apparatus, a steady flow of purge gas was established. The purge gas was connected through a pressure regulator and flow meter to the purge inlet port on the instrument. The flow meter was adjusted to a flow rate of 50 ml/minute purge flow rate over the sample and reference pans.
The DSC cell was cleaned and calibrated according to the instructions in the DSC 2910 Users Manual.

,~

2~8922~
.

The sample material was weighed on an analytical balance, and placed in the DSC sample pan with a crimped lid.
The sample pan was then placed in the DSC cell on the sample platform. A matching empty DSC sample pan with crimped lid was placed on the reference platform. The DSC cell was then closed using the silver lid. The stainless steel lid and bell jar were then applied to the cell if the scan was to be a conventional DSC scan or if the sample was being heated prior to quenching. In other cases, a standard DSC cooling can, without coolant, was applied to the cell, to provide heat sinking during heating rate modulation.
Sample identification, sample weight, the desired underlying heating rate, the starting temperature, the final temperature to be reached, and the modulation frequency and amplitude were programmed into the computer/thermal analyzer.
The DSC experimental sequence was started by pressing the "Start" button on the DSC 2910. The computer/thermal analyzer then automatically heated the sample according to the present invention, as described specifically in Examples 2-4, while deconvoluting and recording the sample temperature, differential heat flow, rapidly reversible component and non-rapidly reversible component of the heat flow using the DFT technique, until the specified final temperature was reached. The furnace then returned to ambient temperature and the sample was unloaded manually.

XAMPLE 2: COMPARISON OF DSC SCANS OF POLY(ETHYLENE
TER~l~ALATE) BY CONVENTIONAL AND
MODULATED DSC

2~8922~
A 4.45 milligram sample of quenched Poly(ethylene terephthalate) (PET) was examined by conventional DSC and the method of the preferred embodiment of the present invention to compare the results obtained by each method. The experimental procedures followed in this example for setting up the apparatus, weighing the samples, loading the samples, and running the analyses were described in Example 1. The sample was conditioned prior to each run by heating the sample to 300 C in the DSC cell; removing the sample from the DSC cell and immediately quench-cooling it to 0 C by placing the sample pan on a block of ice for 5 seconds; reheating the sample in the DSC cell to 90 C; and cooling the sample at 1 C/minute to ambient temperature. The results of the analyses are shown in Figures 2a-2c. Figure 2a is a DSC scan obtained according to the conventional method, at a constant heating rate of 5 C/minute from ambient temperature to 300 C. Figures 2b and 2c are DSC scans obtained according to the preferred embodi-ment (steps 1-8) of the present invention, at an underlying heating rate of 5 C/minute from ambient temperature to 300 oc, using a modulation frequency of 2 cycles/minute and a modulation amplitude of +/- 7.5 C/minute.
Each of the scans shows several curves. Curve 201 (Figure 2a) is a plot of the differential heat flow of the sample as a function of sample temperature. Curve 202 (Figure 2a) is a plot of the derivative with respect to time of the sample tem-perature versus sample temperature. Curve 211 (Figure 2b) is a plot of the differential heat flow of the 2~9~225 .

sample as a function of time. Curve 212 (Figure 2b) is a plot of the derivative with respect to time of the sample temperature versus time. The curves in Figure 2c show the results of deconvoluting the heat flow and temperature data of Figure 2b using the deconvolution algorithms of the preferred embodiment of the present invention. Curve 221 (Figure 2c) is a plot of the non-rapidly reversible component of heat flow of the sample as a function of sample temperature. Curve 223 (Figure 2c) is a plot of the rapidly reversible component of heat flow of the sample as a function of sample temperature.
Curve 222 (Figure 2c) is a plot of the combined heat flow, which is the sum of curve 221 and curve 223, as a function of sample temperature.
PET is a well understood material which produces three well-separated and easily observed heat flow transitions between 50 C and 275 C. In the first transition, the sample passes from the vitreous state to the plastic state, resulting in an increase in the heat capacity of the sample. The first transition appears as feature 203 in Figure 2a; feature 213 in Figure 2b; and features 224, 227 and 230 in Figure 2c. In the second transition, the sample passes from a more disorganized crystalline state to that of a more perfect crystal, giving off heat energy in the process. The second transition appears as feature 204 in Figure 2a; feature 214 in Figure 2c; and features 225, 228 and 231 in Figure 2c. In the third transition, the sample passes from the solid state to the melted state. The third transition appears as feature 205 in 2~8922~

Figure 2a; feature 215 in Figure 2c; and features 226, 229 and 232 in Figure 2c.
The process of heating, quenching, reheating and slow cooling the PET sample freezes several strain effects into the crystal structure of the sample material. These strain effects appear as transitions which can be readily identified in the example curves. The first transition can be seen at approximately 75 C as a small non-reversible endothermic peak overlapped with a glass transition (baseline shift). This transition appears as part of feature 203 of curve 201 (Figure 2a), and feature 227 of curve 222 (Figure 2c). In Figure 2c, it can be seen that the strain peak, feature 224 in curve 221, has been separated from the first transition, feature 227 of curve 222. In a similar fashion, the glass transition, feature 230 of curve 223, has been separated from the baseline shift due to the glass transition of curve 222.
The second transition can be seen at approximately 125 C as a large non-reversible exothermic recrystallization peak in feature 204 of curve 201 (Figure 2a), and feature 228 of curve 222 (Figure 2c). In Figure 2c, curve 221, it can be seen that the recrystallization peak, feature 225, has been separated from the combined heat flow curve, curve 222, and assigned almost completely to the non-rapidly reversible curve (curve 221) as feature 225. It is not presently understood whether the small rapidly reversible feature, 231, of curve 223 is an artifact of the deconvolution process or a small 208~22~

rapidly reversible component of the recrystallization process itself.
The third transition can be seen at approximately 250 C as a large endothermic melt peak in feature 205 of curve 201 (Figure 2a), and feature 229 of curve 222 ~Figure 2c). In Figure 2c, curve 221, it can be seen that an initial exothermic crystal structure change, feature 233, is overlapped with a trailing endothermic event, feature 234, as the melt reaches completion. The initial exotherm is attributed to crystal structure reorganization just prior to the actual melting of the sample crystal. The trailing endotherm is not well understood but may be due in part to super-cooling of the melted sample as the sample temperature decreases momentarily during each modulation cycle. Feature 232 of curve 223 is a large endothermic melt peak.
The deconvoluted scan in Figure 2c can be readily compared to the conventional scan in Figure 2a. Both scans took the same amount of time to complete. However, when compared with the conventional DSC scan in Figure 2a, the separation of overlapped rapidly reversible and non-rapidly reversible events in Figure 2c provides the analyst with greater insight into the nature of the processes taking place at each transition.

EXAMPLE 3: EFFECT OF MODULATION FREQUENCY ON
SEPARATION OF GLASS TRANSITION, RECRYSTALLIZATION AND MELTING EVENTS
INTO RAPIDLY REVERSIBLE AND
NON-RAPIDLY REVERSIBLE HEAT FLOW DATA

2~8922S

A 5.1 milligram sample of quenched Poly(ethylene teraphthalate) (PET) was e~m;ned by the method of the preferred embodiment of the present invention to compare the results obtained using different modulation frequencies. The experimental procedures followed in this example for setting up the apparatus, weighing the samples, loading the samples, and running analyses were described in Example 1. The sample was conditioned prior to each run by heating the sample to 300 C in the DSC cell; removing the sample from the DSC cell and immediately quench-cooling it to 0 C by placing the sample pan on a block of ice for 5 seconds. Figures 3a and 3b show representative DSC scans obtained according to the preferred embodiment (steps 1-8) of the present invention, at an underlying heating rate of 5 C/minute from ambient temperature to 300 C, using various modulation frequencies and approximately constant modulation amplitudes of +/- 7.5 C/minute. Each curve has been normalized, corrected for baseline slope, and smoothed to remove ambient and instrument effects.
Each of the figures shows 5 curves. Curves 301, 302, 303, 304 and 305 (Figure 3a) are plots of the rapidly reversible components of heat flow as a function of sample temperature. Curves 321, 322, 323, 324 and 325 (Figure 3b) are plots of the non-rapidly reversible components of heat flow as a function of sample temperature. Curves 301, 302, 303, 304 and 305 correspond to modulation periods of 10, 20, 30, 40 and 50 seconds/cycle respectively. Curves 321, 322, 323, 324 " ` 20~922~
.

and 325 correspond to modulation periods of 50, 40, 30, 20 and 10 seconds/cycle respectively. Figure 3a shows the effect on rapidly reversible heat flow as the modulation frequency is varied from a cycle period of 10 seconds/cycle (curve 301) to a period of 50 seconds/cycle (curve 305). Figure 3b shows the effect on non-rapidly reversible heat flow as the modulation frequency is varied from a cycle period of 50 seconds/cycle (curve 321) to a period of 10 seconds/cycle (curve 325).
As noted in Example 2, PET is a well understood material which produces three well separated and easily observed heat flow transitions between 50 C and 275 C. The first transition appears as features 306, 309, 312, 315 and 318 in Figure 3a, and as features 326, 329, 332, 335 and 338 in Figure 3b. The second transition appears as features 307, 310, 313, 316 and 319 in Figure 3a, and as features 327, 330, 333, 336 and 339 in Figure 3b. The third transition appears as features 308, 311, 314, 317 and 320 in Figure 3a, and as features 328, 331, 334, 337 and 340 in Figure 3b.
Figure 3a shows that increasing the modulation fre-quency decreases the magnitude of the rapidly reversible com-ponent of heat flow for each transition. The reason for this is not fully understood. It is believed, however, that this is because transitions are time as well as temperature dependent, and high frequency oscillations in heating rate do not allow sufficient time for the completion of reversible transitions. In each case the shape of the curve remains the same.

208922~
Figure 3b shows that increasing the modulation fre-quency changes the shape of the non-rapidly reversible curve as well as affecting the size of the transition. The effect of changing frequency significantly changes the melt peak (features 328, 331, 334, 337 and 340), but has little affect on the recrystallization peak (features 327, 330, 333, 336 and 339). The reason for this is not fully understood. However, it is believed that this is because the recrystallization peak is irreversible, whereas the melt peak contains both reversible and non-reversible components. At high frequencies, the melted sample material super-cools, but at low frequencies it has sufficient time to recrystallize. As can be seen from the curves of Figures 3a and 3b, variation in the modulation frequency is a significant factor in controlling transition effects as measured by the method of the present invention.

EXAMPLE 4: EFFECT OF MODULATION AMPLITUDE ON
SEPARATION OF GLASS TRANSITION, RECRYSTALLIZATION AND MELTING EVENTS
INTO RAPIDLY REVERSIBLE AND
NON-RAPIDLY REVERSIBLE HEAT FLOW DATA

A 5.1 milligram sample of quenched Poly(ethylene teraphalate) (PET) was ~m; ned by the method of the preferred embodiment of the present invention to compare the results obtained using different modulation amplitudes. The experimental procedures followed in this example for setting up the apparatus, weighing the samples, loading the samples, and running analyses were described in Example 1. The sample was conditioned prior to each run by heating the sample to 300 20~922~
.

C in the DSC cell; removing the sample from the DSC cell and immediately quench cooling it to 0 C by placing the sample pan on a block of ice for 5 seconds. Figures 4a and 4b show representative DSC scans obtained according to the preferred embodiment (steps 1-8) of the present invention, at an underlying heating rate of 5 C/minute from ambient temperature to 300 C, using various modulation amplitudes at a constant modulation period of 50 seconds/cycle. Each curve has been normalized, corrected for baseline slope, and smoothed to remove ambient and instrument effects.
Each of the figures shows 3 curves. Curves 401, 402 and 403 (Figure 4a) are plots of the rapidly reversible component of heat flow as a function of sample temperature.
Curves 421, 422 and 423 (Figure 4b) are plots of the non-rapidly reversible components of heat flow as a function of sample temperature. Curves 401, 402 and 403 correspond to modulation amplitudes of +/- 20, +/-10 and +/- 5 C/minute respectively, at a modulation period of 50 seconds/cycle.
Curves 421, 422 and 423 correspond to modulation amplitudes of +/- 5, +/-10 and +/- 20 C/minute respectively, at a modulation period of 50 seconds/cycle. Figure 4a shows the effect of modulation amplitude on rapidly reversible heat flow as the modulation amplitude is varied by +/- 20 C/minute (curve 401) to +/- 5 C/minute (curve 403). Figure 4b shows the effect on rapidly reversible heat flow as the modulation amplitude is varied by +/- 5 C/minute (curve 421) to +/- 20 C/minute (curve 423).

As noted above in Example 2, PET is a well understood material which produces three well separated and easily observed heat flow transitions between 50 C and 275 C. The first transition appears as features 404, 407 and 410 in Figure 4a, and as features 424, 427 and 430 in Figure 4b. The second transition appears as features 405, 408 and 411 in Figure 4a, and as features 425, 428 and 431 in Figure 4b. The third transition appears as features 406, 409 and 412 in Figure 4a, and as features 426, 429 and 432 in Figure 4b.
Figures 4a and 4b show that increasing the modulation amplitude has little affect on the glass transition and recrystallization peak, but has a substantial affect on the melt peak. It is not fully understood why the various transitions change as they do. There is, however, substantial literature to support several theories. It is believed that the glass transition is largely unchanged because this transition is mostly time dependent. It is believed that the recrystallization peak is largely unchanged because this transition is irreversible. It is also believed that the melting transition is affected by a change in amplitude because the width of the temperature excursion on each cycle affects the tendency for super cooling versus recrystallization during the cooling portion of the modulation cycle. As can be seen from the curves of Figures 4a and 4b, variation in modulation amplitude is a significant factor in controlling transition effects as measured by the present invention.

.

208~225 The foregoing disclosure of embodiments of the present invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Many variations and modifications of the embodiments described herein will be obvious to one of ordinary skill in the art in light of the above disclosure.
The scope of the invention is to be defined only by the claims appended hereto, and by their equivalents.

Claims (76)

1. A method for analyzing a material that undergoes a transition as a function of temperature comprising the steps of:
(a) selecting an underlying rate of change of the temperature;
(b) selecting a modulation function;
(c) selecting a modulation frequency;
(d) selecting a modulation amplitude;
(e) placing a sample of the material in an apparatus for detecting differential changes in a characterizing physical parameter of the sample with respect to a reference as a function of the temperature of the sample;
(f) varying the temperature of the sample according to the selected underlying rate of change of the temperature, the selected modulation function, the selected modulation frequency and the selected modulation amplitude;
(g) recording a differential signal representative of differential changes in the characterizing physical parameter; and (h) deconvoluting the signal representative of the characterizing differential physical parameter to compute at least two deconvoluted signals.
2. The method of claim 1, further comprising the step of adjusting the frequency of the modulation of the temperature of the sample according to the at least two deconvoluted signals.
3. The method of claim 1, further comprising the step of adjusting the amplitude of the modulation of the temperature of the sample according to the at least two deconvoluted signals.
4. The analytical method of claim 1, further comprising the step of controlling the underlying rate of change of the temperature of the sample according to the at least two deconvoluted signals.
5. The method of claim 1, wherein the modulation function is a sinusoidal oscillation.
6. The method of claim 1, wherein the modulation function is selected from the group of modulation functions consisting of square waves, sawtooth waves, triangular waves, pulse waves, and combinations thereof.
7. The method of claim 1, wherein the modulation function is a polynomial wave.
8. A method for analyzing a material that undergoes a transition as a function of temperature comprising the steps of:
(a) selecting an underlying rate of change of the temperature;
(b) selecting a modulation function;
(c) selecting a modulation frequency;
(d) selecting a modulation amplitude;
(e) placing a sample of the material in an apparatus for detecting differential changes in a characterizing physical parameter of the sample with respect to a reference as a function of the temperature of the sample;
(f) varying the temperature of the sample according to the selected underlying rate of change of the temperature, the selected modulation function, the selected modulation frequency and the selected modulation amplitude;
(g) recording a differential signal representative of differential changes in the characterizing physical parameter; and (h) deconvoluting the signal representative of the characterizing physical parameters into rapidly reversible and non-rapidly reversible components.
9. The method of claim 8, wherein the modulation frequency is selected to improve the separation between the rapidly reversible and non-rapidly reversible signals.
10. The method of claim 8, wherein the modulation amplitude is selected to improve the separation between the rapidly reversible and non-rapidly reversible signals.
11. The method of claim 1, wherein the characterizing physical parameter is heat flow.
12. The method of claim 1, wherein the characterizing physical parameter is sample weight.
13. The method of claim 1, further comprising deconvoluting the signal representative of the characterizing physical parameter using a discrete Fourier transform.
14. The method of claim 1, further comprising deconvoluting the signal representative of the characterizing physical parameter using a polynomial expression containing the rate of change of the temperature in at least one term.
15. The method of claim 1, further comprising deconvoluting the signal representative of the physical parameter by determining the envelope of the signal representative of the characterizing physical parameter.
16. An analytical apparatus comprising:
(a) means for varying the temperature of a sample at an underlying rate of change;
(b) means for selecting a modulation function, a modulation frequency and a modulation amplitude;
(c) means for modulating the temperature of the sample according to the selected modulation function, modulation frequency and modulation amplitude;
(d) means for detecting a signal representative of differential changes in a characterizing physical parameter of a sample with respect to a reference as a function of the temperature, as the temperature is varied according to the underlying rate of change of the temperature, and modulated according to the modulation function, the modulation frequency and the modulation amplitude;
(e) means for recording the signal representative of differential changes in the characterizing physical parameter; and (f) means for deconvoluting the signal representative of the characterizing differential physical parameter to compute at least two deconvoluted signals.
17. The analytical apparatus of claim 16, wherein the characterizing physical parameter is heat flow.
18. The analytical apparatus of claim 16, wherein the characterizing physical parameter is sample weight.
19. The analytical apparatus of claim 16, wherein the apparatus is a Differential Scanning Calorimeter.
20. The analytical apparatus of claim 16, wherein the modulation function is sinusoidal.
21. The analytical apparatus of claim 16, wherein the modulation function is selected from the group of modulation functions consisting of square waves, sawtooth waves, triangular waves, pulse waves, and combinations thereof.
22. An analytical apparatus comprising:
(a) means for varying the temperature of a sample at an underlying rate of change;
(b) means for selecting a modulation function, a modulation frequency and a modulation amplitude;
(c) means for modulating the temperature of the sample according to the selected modulation function, modulation frequency and modulation amplitude;
(d) means for detecting a signal representative of differential changes in a characterizing physical parameter of a sample with respect to a reference as a function of the temperature, as the temperature is varied according to the underlying rate of change of the temperature, and modulated according to the modulation function, the modulation frequency and the modulation amplitude;
(e) means for recording the signal representative of differential changes in the characterizing physical parameter; and (f) means for deconvoluting the signal representative of differential changes in the characterizing physical parameter into rapidly reversible and non-rapidly reversible components.
23. The analytical apparatus of claim 22, wherein said means for deconvoluting the signal representative of differential changes in the characterizing physical parameter comprises means for carrying out discrete Fourier transforms.
24. The analytical apparatus of claim 22, wherein said means for deconvoluting the signal representative of differential changes in the physical parameter comprises means for fitting the signal to a polynomial expression containing the rate of change of the driving variable in at least one of the terms of the polynomial expression.
25. A method for analyzing a material that undergoes a transition as a function of a driving variable comprising the steps of:
(a) placing a sample of the material in an apparatus for detecting differential changes in a characterizing physical parameter of the sample with respect to a reference as a function of the driving variable;
(b) varying the driving variable at an underlying rate of change modulated by a modulation function, said modulation function having a preselected modulation frequency and a preselected modulation amplitude;
(c) monitoring a differential signal representative of differential changes in the characterizing physical parameter;
(d) controlling the underlying rate of change of the driving variable according to changes in the differential signal representative of differential change in the characterizing physical parameter;
(e) recording the differential signal representative of differential changes in the characterizing physical parameter; and (f) deconvoluting the signal representative of the characterizing physical parameter and the driving variable into at least two deconvoluted signals.
26. The method of claim 25, wherein the modulation function is a sinusoidal oscillation.
27. The method of claim 25, wherein the modulation function is selected from the group of modulation functions consisting of square waves, sawtooth waves, triangular waves, pulse waves, and combinations thereof.
28. The method of claim 27, wherein the driving variable is temperature.
29. The method of claim 28, wherein the characterizing physical parameter is heat flow.
30. The method of claim 28, wherein the characterizing physical parameter is sample weight.
31. The method of claim 25, further comprising deconvoluting the signal representative of the characterizing physical parameter using a discrete Fourier transform.
32. A method for analyzing a material that undergoes a transition as a function of a driving variable comprising the steps of:
(a) placing a sample of the material in an apparatus for detecting differential changes in a characterizing physical parameter of the sample with respect to a reference as a function of the driving variable;
(b) varying the driving variable at an underlying rate of change modulated by a modulation function, said modulation function having a preselected modulation frequency and a preselected modulation amplitude;
(c) monitoring a differential signal representative of differential changes in the characterizing physical parameter;
(d) controlling the underlying rate of change of the driving variable according to changes in the differential signal representative of differential change in the characterizing physical parameter; and (e) deconvoluting the signal representative of the characterizing physical parameter and the driving variable into rapidly reversible and non-rapidly reversible components.
33. A method for analyzing a material using a differential scanning calorimeter comprising the steps of:
(a) selecting an underlying heating rate, modulation frequency and modulation amplitude;
(b) placing a sample of the material in the differential scanning calorimeter;
(c) varying the temperature of the sample in the differential scanning calorimeter according to the selected underlying heating rate, the selected modulation frequency and the selected modulation amplitude;
(d) recording a signal representative of differential changes in the heat flow to and from the sample; and (e) deconvoluting the signal representative of differential changes in the heat flow to and from the sample to compute at least one deconvoluted signal.
34. The method of claim 33, wherein the step of deconvoluting the signal representative of differential changes in the heat flow to and from the sample to compute at least one deconvoluted signal comprises deconvoluting the signal into rapidly reversible and non-rapidly reversible components.
35. The method of claim 34, further comprising the step of adjusting the frequency of the modulation of the temperature according to the at least one deconvoluted signal.
36. The method of claim 34, further comprising the step of adjusting the amplitude of the modulation of the temperature according to the at least one deconvoluted signal.
37. The method of claim 34, further comprising the step of controlling the underlying heating rate according to the at least one deconvoluted signal.
38. A method for analyzing a material using a differential thermal analyzer comprising the steps of:
(a) selecting an underlying heating rate, modulation frequency and modulation amplitude;
(b) placing a sample of the material in a differential thermal analyzer;
(c) varying the temperature of the sample in the differential thermal analyzer according to the selected underlying heating rate, the selected modulation frequency and the selected modulation amplitude;
(d) recording a signal representative of differential changes in the heat flow to and from the sample; and (e) deconvoluting the signal representative of differential changes in the heat flow to and from the sample to compute at least one deconvoluted signal.
39. The method of claim 38, wherein the step of deconvoluting the signal representative of differential changes in the heat flow to and from the sample to compute at least one deconvoluted signal comprises deconvoluting the signal into rapidly reversible and non-rapidly reversible components.
40. The method of claim 39, further comprising the step of adjusting the frequency of the modulation of the temperature according to the at least one deconvoluted signal.
41. The method of claim 39, further comprising the step of adjusting the amplitude of the modulation of the temperature according to the at least one deconvoluted signal.
42. The method of claim 39, further comprising the step of controlling the underlying heating rate according to the at least one deconvoluted signal.
43. A differential scanning calorimeter comprising:
(a) means for varying the temperature of a sample in the differential scanning calorimeter according to an underlying heating rate;
(b) means for selecting a modulation frequency and a modulation amplitude;
(c) means for controlling the temperature of the sample according to the selected underlying heating rate, modulation frequency and modulation amplitude;

(d) means for detecting the heat flow to and from the sample with respect to a reference as a function of temperature, as the temperature is varied according to the modulation frequency and the modulation amplitude;
(e) means for recording a signal representative of differential changes in the heat flow to and from the sample; and (f) means for deconvoluting the signal representative of differential changes in the heat flow to and from the sample to compute at least one deconvoluted signal.
44. The differential scanning calorimeter of claim 43, wherein the means for deconvoluting the signal representative of differential changes in the heat flow to and from the sample to compute at least one deconvoluted signal comprises means for deconvoluting the signal into rapidly reversible and non-rapidly reversible components.
45. The differential scanning calorimeter of claim 44, further comprising means for adjusting the frequency of the modulation of the temperature according to the at least one deconvoluted signal.
46. The differential scanning calorimeter of claim 44, further comprising means for adjusting the amplitude of the modulation of the temperature according to the at least one deconvoluted signal.
47. The differential scanning calorimeter of claim 44, further comprising means for controlling the underlying heating rate according to the at least one deconvoluted signal.
48. A differential thermal analyzer comprising:
(a) means for varying the temperature of a sample in the differential thermal analyzer according to an underlying heating rate;

(b) means for selecting a modulation frequency and a modulation amplitude;
(c) means for controlling the temperature of the sample according to the selected underlying heating rate, modulation frequency and modulation amplitude;
(d) means for detecting the heat flow to and from the sample with respect to a reference as a function of temperature, as the temperature is varied according to the modulation frequency and the modulation amplitude;
(e) means for recording a signal representative of differential changes in the heat flow to and from the sample; and (f) means for deconvoluting the signal representative of differential changes in the heat flow to and from the sample to compute at least one deconvoluted signal.
49. The differential thermal analyzer of claim 48, wherein the means for deconvoluting the signal representative of differential changes in the heat flow to and from the sample to compute at least one deconvoluted signal comprises means for deconvoluting the signal representative of differential changes in the heat flow to and from the sample into rapidly reversible and non-rapidly reversible components.
50. The differential thermal analyzer of claim 49, further comprising means for adjusting the frequency of the modulation of the temperature according to the at least one deconvoluted signal.
51. The differential thermal analyzer of claim 49, further comprising means for adjusting the amplitude of the modulation of the temperature according to the at least one deconvoluted signal.
52. The differential thermal analyzer of claim 49, further comprising means for controlling the underlying heating rate according to the at least one deconvoluted signal.
53. A method for analyzing a material comprising the steps of:
(a) placing a sample of the material in an apparatus for detecting differential changes in the heat flow to a sample material with respect to a reference, as a function of temperature;
(b) varying the temperature at an underlying heating rate modulated by a modulation function, said modulation function having a preselected modulation frequency and a preselected modulation amplitude;
(c) monitoring a differential signal representative of the differential change in the heat flow to the sample material with respect to the reference;
(d) recording the differential signal representative of the differential change in the heat flow to the sample material with respect to the reference; and (e) deconvoluting the signal representative of the differential change in the heat flow to the sample material with respect to the reference to compute at least one deconvoluted signal.
54. The method of claim 53, wherein the step of deconvoluting the signal representative of the differential change in the heat flow to the sample material with respect to the reference to compute at least one deconvoluted signal comprises deconvoluting the signal representative of the differential change in the heat flow to the sample material with respect to the reference, into rapidly reversing and non-rapidly reversing components.
55. The method of claim 53, wherein the modulation function is a sinusoidal oscillation.
56. The method of claim 53, wherein the modulation function is a combination of at least two sinusoidal oscillations.
57. The method of claim 53, wherein the modulation function is selected from the group of modulation functions consisting of square waves, sawtooth waves, triangular waves, pulse waves, polynomial waves, and combinations thereof.
58. The method of claim 53, further comprising the step of deconvoluting the signal representative of the differential change in the heat flow to the sample material with respect to the reference, using a discrete Fourier transform.
59. The method of claim 58, wherein the signal representative of differential changes in the heat flow to and from the sample is differential temperature.
60. The method of claim 53, wherein the differential signal representative of the differential change in the heat flow to the sample material with respect to the reference, is differential temperature.
61. A thermal analysis instrument comprising:
(a) a furnace comprising a heater, a heater controller, and a furnace chamber;
(b) a sample pan and a reference pan in the furnace chamber;
(c) means for monitoring the temperature of the sample pan and the temperature difference between the sample pan and the reference pan;
(d) means for controlling the temperature of the furnace chamber;
(e) means for receiving a signal representative of the temperature of the sample pan and of the temperature difference between the sample pan and the reference pan, for calculating a signal representative of differential changes in heat flow to the sample pan with respect to heat flow to the reference pan from the signal representative of the temperature of the sample pan and of the temperature difference between the sample pan and the reference pan, and for controlling the means for controlling the temperature of the furnace chamber;
(f) means for (i) selecting an underlying heating rate for the furnace chamber, (ii) selecting a modulation frequency and a modulation amplitude, and (iii) controlling the temperature of the sample pan according to the selected underlying heating rate, modulation frequency and modulation amplitude;
(g) means for recording the signal representative of differential changes in the heat flow to the sample pan with respect to the heat flow to the reference pan; and (h) means for deconvoluting the signal representative of differential changes in the heat flow to the sample pan with respect to the heat flow to the reference pan to compute at least one deconvoluted signal.
62. The thermal analysis instrument of claim 61, wherein the means for deconvoluting the signal representative of differential changes in the heat flow to the sample pan with respect to the heat flow to the reference pan to compute at least one deconvoluted signal comprises means for deconvoluting the signal representative of differential changes in the heat flow to the sample pan with respect to the heat flow to the reference pan into rapidly reversible and non-rapidly reversible components.
63. The thermal analysis instrument of claim 62, wherein the means for deconvoluting the signal representative of differential changes in the heat flow to the sample pan with respect to the heat flow to the reference pan into rapidly reversible and non-rapidly reversible components uses a discrete differential Fourier transform technique.
64. The thermal analysis instrument of claim 61, wherein the sample pan and the reference pan are on a support in the furnace chamber, and wherein the support serves as the major heat flow path for transferring heat from the furnace to the sample pan and to the reference pan.
65. A thermal analysis instrument comprising:
(a) a sample position and a reference position;
(b) means for heating a sample placed at the sample position and a reference placed at the reference position;
(c) means for monitoring the heat flow to the sample and the heat flow to the reference;
(d) means for receiving a signal representative of the heat flow to the sample and the heat flow to the reference;
(e) means for recording the signal representative of the heat flow to the sample and the heat flow to the reference;
(f) means for selecting an underlying heating rate, modulation frequency and modulation amplitude;
(g) means for controlling the temperature of the sample according to the selected underlying heating rate, modulation frequency and modulation amplitude;
(h) means for calculating a signal representative of differential changes in the heat flow to the sample with respect to the heat flow to the reference; and (i) means for deconvoluting the signal representative of differential changes in the heat flow to the sample with respect to the heat flow to the reference to compute at least one deconvoluted signal.
66. The thermal analysis instrument of claim 65, wherein the means for deconvoluting the signal representative of differential changes in the heat flow to the sample with respect to the heat flow to the reference to compute at least one deconvoluted signal comprises means for deconvoluting the signal representative of differential changes in the heat flow to the sample with respect to the heat flow to the reference into rapidly reversible and non-rapidly reversible components.
67. The thermal analysis instrument of claim 66, wherein the means for deconvoluting the signal representative of differential changes in the heat flow to the sample with respect to the heat flow to the reference into rapidly reversible and non-rapidly reversible components uses a discrete differential Fourier transform technique.
68. The thermal analysis instrument of claim 65, wherein the sample and the reference are on a support, and wherein the support serves as the major heat flow path for heat transfer.
69. A method for analyzing a material using a differential scanning calorimeter comprising the steps of:
(a) selecting an underlying heating rate, modulation frequency and modulation amplitude;
(b) placing a sample of the material in the differential scanning calorimeter;
(c) varying the temperature of the sample in the differential scanning calorimeter according to the selected underlying heating rate, the selected modulation frequency and the selected modulation amplitude;
(d) recording a signal representative of differential changes in the heat flow to and from the sample; and (e) deconvoluting the signal representative of differential changes in the heat flow to and from the sample to compute two deconvoluted signals.
70. The method of claim 69, wherein the step of deconvoluting the signal representative of differential changes in the heat flow to and from the sample to compute two deconvoluted signals comprises deconvoluting the signal into a rapidly reversible component and a non-rapidly reversible component.
71. A method for analyzing a material using a differential thermal analyzer comprising the steps of:
(a) selecting an underlying heating rate, modulation frequency and modulation amplitude;
(b) placing a sample of the material in a differential thermal analyzer;
(c) varying the temperature of the sample in the differential thermal analyzer according to the selected underlying heating rate, the selected modulation frequency and the selected modulation amplitude;
(d) recording a signal representative of differential changes in the heat flow to and from the sample; and (e) deconvoluting the signal representative of differential changes in the heat flow to and from the sample to compute two deconvoluted signals.
72. The method of claim 71, wherein the step of deconvoluting the signal representative of differential changes in the heat flow to and from the sample to compute two deconvoluted signals comprises deconvoluting the signal into a rapidly reversible component and a non-rapidly reversible component.
73. A differential scanning calorimeter comprising:
(a) means for varying the temperature of a sample in the differential scanning calorimeter according to an underlying heating rate;
(b means for selecting a modulation frequency and a modulation amplitude;
(c) means for controlling the temperature of the sample according to the selected underlying heating rate, modulation frequency and modulation amplitude;
(d) means for detecting the heat flow to and from the sample with respect to a reference as a function of temperature, as the temperature is varied according to the modulation frequency and the modulation amplitude;
(e) means for recording a signal representative of differential changes in the heat flow to and from the sample; and (f) means for deconvoluting the signal representative of differential changes in the heat flow to and from the sample to compute two deconvoluted signals.
74. The differential scanning calorimeter of claim 73, wherein the means for deconvoluting the signal representative of differential changes in the heat flow to and from the sample to compute two deconvoluted signals comprises means for deconvoluting the signal into a rapidly reversible component and a non-rapidly reversible component.
75. A differential thermal analyzer comprising:
(a) means for varying the temperature of a sample in the differential thermal analyzer according to an underlying heating rate;
(b) means for selecting a modulation frequency and a modulation amplitude;
(c) means for controlling the temperature of the sample according to the selected underlying heating rate, modulation frequency and modulation amplitude;
(d) means for detecting the heat flow to and from the sample with respect to a reference as a function of temperature, as the temperature is varied according to the modulation frequency and the modulation amplitude;
(e) means for recording a signal representative of differential changes in the heat flow to and from the sample; and (f) means for deconvoluting the signal representative of differential changes in the heat flow to and from the sample to compute two deconvoluted signals.
76. The differential thermal analyzer of claim 75, wherein the means for deconvoluting the signal representative of differential changes in the heat flow to and from the sample to compute two deconvoluted signals comprises means for deconvoluting the signal representative of differential changes in the heat flow to and from the sample into a rapidly reversible component and a non-rapidly reversible component.
CA002089225A 1992-03-02 1993-02-10 Method and apparatus for modulated differential analysis Expired - Lifetime CA2089225C (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US844,448 1992-03-02
US07844448 US5224775C2 (en) 1992-03-02 1992-03-02 Method and apparatus for modulated differential analysis

Publications (2)

Publication Number Publication Date
CA2089225A1 CA2089225A1 (en) 1993-06-13
CA2089225C true CA2089225C (en) 1995-07-25

Family

ID=25292741

Family Applications (1)

Application Number Title Priority Date Filing Date
CA002089225A Expired - Lifetime CA2089225C (en) 1992-03-02 1993-02-10 Method and apparatus for modulated differential analysis

Country Status (5)

Country Link
US (2) US5224775C2 (en)
EP (1) EP0559362B1 (en)
JP (2) JP3299575B2 (en)
CA (1) CA2089225C (en)
DE (1) DE69306018T2 (en)

Families Citing this family (103)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5474385A (en) * 1992-03-02 1995-12-12 Ta Instruments, Inc. Method and apparatus for parsed dynamic differential analysis
US5624187A (en) * 1992-03-02 1997-04-29 Ta Instruments, Inc. Method and apparatus for gas flow modulated differential scanning calorimetry
US5335993A (en) * 1992-03-02 1994-08-09 Ta Instruments, Inc. Method and apparatus for thermal conductivity measurements
US5248199A (en) * 1992-03-02 1993-09-28 Ta Instruments, Inc. Method and apparatus for spatially resolved modulated differential analysis
US5224775C2 (en) * 1992-03-02 2002-04-23 Ta Instr Inc Method and apparatus for modulated differential analysis
US5439291C1 (en) * 1992-03-02 2002-04-16 Ta Instr Inc Method and apparatus for ac differential thermal analysis
US5588746A (en) * 1993-07-22 1996-12-31 Sumitomo Chemical Company, Limited Apparatus for thermal analysis
JP2909950B2 (en) * 1993-09-24 1999-06-23 セイコーインスツルメンツ株式会社 Thermal analyzer
US5549387A (en) * 1994-06-01 1996-08-27 The Perkin-Elmer Corporation Apparatus and method for differential analysis using real and imaginary signal components
JP3556227B2 (en) * 1994-06-01 2004-08-18 ザ パーキン−エルマー コーポレイション Apparatus and method for differential analysis using real and imaginary signal components
FI113405B (en) * 1994-11-02 2004-04-15 Jarmo Juhani Enala Real-time measurement procedure
AU1279495A (en) * 1994-12-13 1996-07-03 Consiglio Nazionale Delle Ricerche Multiharmonic calorimetric spectroscopy
US5833365A (en) * 1995-03-24 1998-11-10 Interuniversitair Micro-Electronika Centrum Vzw Method for local temperature sensing for use in performing high resolution in-situ parameter measurements
EP0733909B1 (en) * 1995-03-24 2004-11-17 Interuniversitair Micro Elektronica Centrum Vzw Method and apparatus for local temperature sensing for use in performing high resolution in-situ measurement
JP3591917B2 (en) * 1995-06-06 2004-11-24 キヤノン株式会社 Collaborative work support method and system
US5520042A (en) * 1995-06-19 1996-05-28 Rheometric Scientific Apparatus and method for the simultaneous measurement of rheological and thermal characteristics of materials and measuring cell therefor
TW473518B (en) 1995-07-28 2002-01-21 Ciba Sc Holding Ag Soluble chromophores containing solubilising groups which can be easily removed
US5823677A (en) * 1996-03-18 1998-10-20 The Board Of Trustees Of Western Michigan Method of identifying a substance by infrared imaging
US6095679A (en) * 1996-04-22 2000-08-01 Ta Instruments Method and apparatus for performing localized thermal analysis and sub-surface imaging by scanning thermal microscopy
US5842788A (en) * 1996-11-01 1998-12-01 Ta Instruments, Inc. Differential scanning calorimeter
US6405137B1 (en) * 1996-12-31 2002-06-11 Ta Instruments, Inc. Method and apparatus for performing chemical analysis using imaging by scanning thermal microscopy
US6200022B1 (en) 1997-04-21 2001-03-13 Ta Instruments, Inc. Method and apparatus for localized dynamic mechano-thermal analysis with scanning probe microscopy
US6113261A (en) 1997-06-27 2000-09-05 Ta Instruments, Inc. Method and apparatus of modulated-temperature thermogravimetry
US6099162A (en) * 1997-10-24 2000-08-08 Hydril Company Resin cure monitor
US5996337A (en) * 1998-02-06 1999-12-07 Engelhard Corporation Dynamic calorimetric sensor system
US6007240A (en) * 1998-04-14 1999-12-28 Ta Instruments, Inc. Method and apparatus for modulated-temperature thermomechanical analysis
EP0990893B1 (en) * 1998-10-01 2003-03-05 Mettler-Toledo GmbH Single cell calorimeter
US6438497B1 (en) 1998-12-11 2002-08-20 Symyx Technologies Method for conducting sensor array-based rapid materials characterization
US6477479B1 (en) 1998-12-11 2002-11-05 Symyx Technologies Sensor array for rapid materials characterization
JP2002532717A (en) * 1998-12-11 2002-10-02 サイミックス テクノロジーズ、インク Sensor array based system and method for rapid material characterization
US6406918B1 (en) * 1999-01-25 2002-06-18 University Of Massachusetts Thermal analysis for detection and identification of explosives and other controlled substances
US6286992B1 (en) * 1999-02-12 2001-09-11 Meritor Heavy Vehicle Systems, Llc Axle temperature monitor
JP3242899B2 (en) * 1999-04-27 2001-12-25 セイコーインスツルメンツ株式会社 Thermal analyzer
US6238087B1 (en) * 1999-07-13 2001-05-29 Caterpillar Inc. Method and apparatus for characterizing a quench
WO2001009597A1 (en) * 1999-07-28 2001-02-08 Microcal, Llc Pressure perturbation calorimetry instruments and methods
EP1091208B1 (en) * 1999-09-27 2002-10-30 Mettler-Toledo GmbH Method and apparatus for thermally analyzing a material
AU1476601A (en) 1999-11-09 2001-06-06 Sri International Array for the high-throughput synthesis, screening and characterization of combinatorial libraries, and methods for making the array
US7033840B1 (en) 1999-11-09 2006-04-25 Sri International Reaction calorimeter and differential scanning calorimeter for the high-throughput synthesis, screening and characterization of combinatorial libraries
DE60024774T2 (en) 2000-02-03 2006-09-07 Mettler-Toledo Gmbh Modulation method and apparatus for the thermal analysis of a material
US6431747B1 (en) 2000-03-23 2002-08-13 Ta Instruments, Inc. Heat flux differential scanning calorimeter sensor
US6561692B2 (en) 2000-03-23 2003-05-13 Ta Instruments-Waters Llc Differential scanning calorimeter
US6488406B2 (en) 2000-03-23 2002-12-03 Ta Instruments-Waters, Llc Differential scanning calorimeter
US6428203B1 (en) 2000-03-23 2002-08-06 Ta Instruments, Inc. Power compensation differential scanning calorimeter
DE60108684T2 (en) * 2000-06-06 2006-01-12 Matsushita Electric Industrial Co., Ltd., Kadoma A method for estimating the quality of a lead-free solder and method for wave soldering
US6497509B2 (en) 2000-06-08 2002-12-24 Perkinelmer Instruments Llc Method for measuring absolute value of thermal conductivity
EP1182439B1 (en) * 2000-08-23 2016-04-13 TA Instruments - Waters LLC Power compensation differential scanning calorimeter
JP4375699B2 (en) 2000-09-14 2009-12-02 株式会社リコー Tandem image forming apparatus, image forming apparatus including the same, and method for arranging image forming means
US6843595B2 (en) * 2001-01-26 2005-01-18 Waters Investment Limited Differential scanning calorimeter accounting for heat leakage
US6760679B1 (en) 2001-01-26 2004-07-06 Ta Instruments-Waters, Llc Method and apparatus for positional calibration of a thermal analysis instrument
US6523998B1 (en) 2001-01-26 2003-02-25 Ta Instruments, Inc. Thermal analysis assembly with distributed resistance and integral flange for mounting various cooling devices
US6823278B1 (en) 2001-01-26 2004-11-23 Ta Instruments-Waters, Llc Method and apparatus for positional calibration of a thermal analysis instrument
US6644136B1 (en) 2001-01-26 2003-11-11 Ta Instruments-Waters, Llc Sample tray for automatic sampler
US6846455B1 (en) 2001-01-26 2005-01-25 Ta Instruments-Waters, Llc Automatic sampling device
US6859271B1 (en) 2001-01-26 2005-02-22 Ta Instruments-Waters Llc Platen for automatic sampler
US6652015B1 (en) 2001-01-26 2003-11-25 Ta Instruments-Waters Llc Gripper device
US6641300B1 (en) 2001-01-29 2003-11-04 Waters Investment, Ltd. Differential scanning calorimeter
DE60142083D1 (en) * 2001-06-08 2010-06-17 Perkinelmer Health Sci Inc METHOD FOR MEASURING THE ABSOLUTE VALUE OF HEAT CONDUCTIVITY
US6491426B1 (en) 2001-06-25 2002-12-10 Sbs Technologies Inc. Thermal bond verification
DE60213730T2 (en) * 2001-08-31 2007-08-16 The University Of Utah Research Foundation, Salt Lake City Real-time quantification with internal standards
US20050036536A1 (en) * 2001-09-18 2005-02-17 Lewis Edwin A. High throughout energy array
US6648504B2 (en) * 2002-03-01 2003-11-18 Waters Investment Limited System and method for calibrating contact thermal resistances in differential scanning calorimeters
ATE521886T1 (en) 2002-06-10 2011-09-15 Mettler Toledo Ag METHOD AND DEVICE FOR THE THERMAL ANALYSIS OF A MATERIAL
NL1021400C2 (en) * 2002-09-05 2004-03-08 Tno Method and device for determining a phase transition of a substance.
GB0227009D0 (en) * 2002-11-19 2002-12-24 Worlds Apart Ltd Convertible blanket
US20040141541A1 (en) * 2002-12-02 2004-07-22 John Williams MEMS-based thermogravimetric analyzer
EP1594908B1 (en) 2003-02-19 2012-08-01 Orteq B.V. Method for the preparation of new segmented polyurethanes with high tear and tensile strengths and method for making porous scaffolds
US7448798B1 (en) 2003-06-18 2008-11-11 Veeco Instruments Inc. Scanning thermal probe microscope
DE50308067D1 (en) * 2003-07-04 2007-10-11 Mettler Toledo Ag Method and device for substance analysis
US6871998B2 (en) * 2003-08-01 2005-03-29 Hitachi Global Storage Technologies Netherlands B.V. Method for calibrating a vacuum thermogravimetric analyzer for determination of vapor pressures of compounds
US7059768B2 (en) * 2003-08-01 2006-06-13 Hitachi Global Storage Technologies Netherlands Standards for the calibration of a vacuum thermogravimetric analyzer for determination of vapor pressures of compounds
US20050025212A1 (en) * 2003-08-01 2005-02-03 Carter Malika Dothresa Standards for the calibration of a vacuum thermogravimetric analyzer for determination of vapor pressures of compounds
EP1834172B1 (en) * 2005-01-04 2019-05-08 Mettler-Toledo GmbH Method and device for analyzing substances
JP4852740B2 (en) * 2005-04-26 2012-01-11 国立大学法人 千葉大学 Differential scanning calorimeter capable of measuring high pressure and differential scanning heat flow meter using the same
FR2886730B1 (en) * 2005-06-02 2007-07-27 Inst Francais Du Petrole METHOD OF ANALYZING THE KINETICS OF FORMATION OF HYDRATE GAS IN FLUIDS
US8292496B1 (en) 2005-07-27 2012-10-23 L-3 Communications Cyterra Corporation Energetic material detector
US20110151575A1 (en) * 2005-07-27 2011-06-23 L-3 Communications Cyterra Corporation Energetic Material Detector
CA2617191A1 (en) * 2005-07-27 2007-01-27 L-3 Communications Cyterra Corporation Energetic material detector
US7470057B2 (en) * 2006-08-24 2008-12-30 Waters Investments Limited Differential scanning calorimeter sensor and method
US7578613B2 (en) * 2006-09-14 2009-08-25 Waters Investments Limited Modulated differential scanning calorimeter solvent loss calibration apparatus and method
JP2009053143A (en) * 2007-08-29 2009-03-12 National Institute Of Advanced Industrial & Technology Sample cell for differential scanning calorimeter
JP5043734B2 (en) * 2008-03-27 2012-10-10 株式会社住化分析センター Resin heat history estimation method
WO2009141732A2 (en) * 2008-05-19 2009-11-26 Orteq B.V. Polyurethane foam for use in medical implants
JP2010066251A (en) * 2008-08-12 2010-03-25 Mitsubishi Materials Corp Device and method for analyzing chlorosilanes
EP2380011B1 (en) * 2009-01-20 2013-06-19 PerkinElmer Singapore Pte. Ltd. Differential scanning calorimetry and calibration methods for use therewith
EP2214005B1 (en) * 2009-02-03 2019-09-18 Mettler-Toledo GmbH Thermo-Analytical Instrument
DE102012005414B4 (en) 2011-03-14 2018-08-23 Technische Universität Ilmenau Method for the automatic detection of a phase transformation with energy conversion
FR2983740B1 (en) * 2011-12-07 2014-02-14 Centre Nat Rech Scient METHOD FOR DETERMINING THE REACTION MECHANISM OF A REACTION AND ASSOCIATED DEVICE
US9869595B2 (en) * 2012-07-06 2018-01-16 Council Of Scientific & Industrial Research Device for thermokinetic property measurement
CN103837566B (en) * 2012-11-27 2016-08-03 中国石油天然气股份有限公司 A kind of method of the detection viscosity index improver containing hypocrystalline glue
CN103196910B (en) * 2013-01-21 2016-03-30 北京空间飞行器总体设计部 A kind of temperature variant method of test Loading Materials for Initiating Explosive Devices performance
DE102013011730B3 (en) * 2013-07-12 2014-08-14 Netzsch-Gerätebau GmbH Method for evaluating a measurement result of a thermal analysis, and use of the method, computer device, computer program product and system for carrying out the method
US9389194B2 (en) 2013-09-13 2016-07-12 Netzsch-Geraetebau Gmbh System and method for analysis in modulated thermogravimetry
EP2942612A1 (en) * 2014-05-06 2015-11-11 Mettler-Toledo AG Temperature Modulated Thermogravimetric Analysis
JP5933653B2 (en) * 2014-08-22 2016-06-15 ネッチ ゲレーテバウ ゲーエムベーハー Thermal analysis apparatus and thermal analysis method
CN104697827A (en) * 2014-11-21 2015-06-10 中南大学 Preparation and thermal analysis method of alloy sample containing high-volatility elements with high reaction activity
CN104483343B (en) * 2014-12-29 2017-11-14 成都光明光电股份有限公司 The thermometry of crystallization and thermal treatment
EP3130679B1 (en) 2015-08-13 2018-02-28 Cladiac GmbH Method and test system for the detection and/or quantification of a target nucleic acid in a sample
CN105954318A (en) * 2016-04-27 2016-09-21 山东大学 Detection method of energy loss in copper-based memory alloy martensite phase transformation
CN106324033A (en) * 2016-08-16 2017-01-11 西安近代化学研究所 Visualized explosive cooking-off and gas product analysis device
CN107064565A (en) * 2017-05-27 2017-08-18 中国科学院宁波材料技术与工程研究所 The hot many reference amounts coupling microscope probe of magnetoelectricity, its preparation method and detection method
JP6682485B2 (en) * 2017-09-12 2020-04-15 エスペック株式会社 Heat capacity measuring device and heat capacity measuring method
JP7141608B2 (en) * 2018-12-13 2022-09-26 株式会社東レリサーチセンター A method for measuring the glass transition temperature of thermosetting resins using high-speed calorimetry
CN110146539B (en) * 2019-05-13 2021-09-10 南京理工大学 Method for evaluating minimum decomposition starting temperature of material thermal decomposition reaction

Family Cites Families (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2975629A (en) * 1958-06-06 1961-03-21 Patent & Licensing Corp Test equipment for determining temperature change characteristics of materials
US3263484A (en) * 1962-04-04 1966-08-02 Perkin Elmer Corp Differential microcalorimeter
US3271996A (en) * 1965-11-24 1966-09-13 Paulik Ferenc Apparatus for thermal analysis
US3339398A (en) * 1964-03-30 1967-09-05 Chevron Res High sensitivity differential thermal analysis apparatus and method
GB1063898A (en) * 1964-09-03 1967-04-05 Atomic Energy Authority Uk Improvements in or relating to methods and apparatus for differential thermal analysis
US3360993A (en) * 1965-08-27 1968-01-02 Air Force Usa Single thermocouple differentiating method and system
US3789662A (en) * 1971-10-26 1974-02-05 Instrumentation Labor Inc Calorimetry
US4255961A (en) * 1978-10-17 1981-03-17 University Of Va. Alumni Patents Foundation Differential calorimeter based on the heat leak principle
US4350446A (en) * 1980-11-03 1982-09-21 E. I. Du Pont De Nemours And Company Method and apparatus for calorimetric differential thermal analysis
HU194405B (en) * 1985-05-10 1988-01-28 Magyar Optikai Muevek Temperature control system for testing thermic phase transformations
DE3529489A1 (en) * 1985-08-16 1987-02-26 Max Planck Gesellschaft METHOD AND DEVICE FOR DETERMINING THE HEAT CAPACITY OF A SAMPLE
US4838706A (en) * 1986-03-24 1989-06-13 The Provost, Fellows And Scholars Of The College Of The Holy And Undivided Trinity Of Queen Elizabeth Near Dublin Thermal analysis
US4747698A (en) * 1986-04-30 1988-05-31 International Business Machines Corp. Scanning thermal profiler
US4690569A (en) * 1986-05-22 1987-09-01 Qualtronics Corporation Thermal profile system
US4840496A (en) * 1988-02-23 1989-06-20 The United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration Noncontact temperature pattern measuring device
FR2642169B1 (en) * 1989-01-26 1992-02-07 Solomat Partners Lp METHOD FOR ANALYZING RELAXATION SPECTRAS AND RESONANCES IN MATERIALS
GB2233457A (en) * 1989-06-21 1991-01-09 Schlumberger Technologies Ltd Temperature reference junction for a multichannel temperature sensing system.
JPH0795049B2 (en) * 1989-08-30 1995-10-11 三井東圧化学株式会社 Method of measuring thermal diffusivity by alternating current heating, method of measuring thermal conductivity and thermal diffusivity measuring device
US5165792A (en) * 1991-01-08 1992-11-24 Ta Instruments, Inc. Method and apparatus for high resolution analysis
US5224775C2 (en) * 1992-03-02 2002-04-23 Ta Instr Inc Method and apparatus for modulated differential analysis

Also Published As

Publication number Publication date
US5224775A (en) 1993-07-06
JPH07181154A (en) 1995-07-21
US5346306C1 (en) 2002-05-07
US5224775B1 (en) 1994-07-19
EP0559362A1 (en) 1993-09-08
JPH11190706A (en) 1999-07-13
DE69306018T2 (en) 1997-03-13
US5346306A (en) 1994-09-13
JP3299575B2 (en) 2002-07-08
DE69306018D1 (en) 1997-01-02
CA2089225A1 (en) 1993-06-13
US5224775C2 (en) 2002-04-23
EP0559362B1 (en) 1996-11-20

Similar Documents

Publication Publication Date Title
CA2089225C (en) Method and apparatus for modulated differential analysis
US5439291A (en) Method and apparatus for AC Differential thermal analysis
US5165792A (en) Method and apparatus for high resolution analysis
US5335993A (en) Method and apparatus for thermal conductivity measurements
US5711604A (en) Method for measuring the coefficient of heat conductivity of a sample
EP0701122B1 (en) Method and apparatus for parsed dynamic differential calorimetric analysis
EP1136802B1 (en) Modulated differential scanning calorimeter
US5983711A (en) Temperature controlled gravimetric moisture analyzer and method therefor
US5713665A (en) Method and apparatus for thermal diffusivity measurement
US6007240A (en) Method and apparatus for modulated-temperature thermomechanical analysis
JP3556227B2 (en) Apparatus and method for differential analysis using real and imaginary signal components
Wunder et al. Pressure measurement at high temperatures in the diamond anvil cell
EP0747694A2 (en) Method and apparatus for gas flow modulated differential scanning calorimetry
JPH1019815A (en) Thermal analysis and x-ray measuring device
Schaich et al. Structural changes accompanying the hydrogen desorption from the diamond C (111): H (1× 1)-surface revisited by helium atom scattering
Wu et al. Fast DSC applied to the crystallization of polypropylene
Bordui et al. Curie temperature measurements on KTiOPO4 single crystals grown by flux and hydrothermal techniques
Wangmaneerat et al. Determination of temperature and composition of phosphosilicate glass thin films from infrared emission spectral data
Huang et al. A dynamic FT‐IR method for determining the curing temperature ranges of an acetylene‐terminated polyisoimide prepolymer
Casson et al. FTIR sample cell thermal lag calibration using phase transitions in three molecular solids
Blaine Isothermal crystallization of polypropylene by differential scanning calorimetry
JP3227008B2 (en) Measurement method of Curie point temperature of oxide piezoelectric material in thermal analysis
Allen Adiabatic Calorimeter for the study of exothermic chemical reactions
EP1402249B1 (en) Method for measuring absolute value of thermal conductivity
Möller et al. Temperature‐jump apparatus with infrared detection for relaxation studies in thin samples

Legal Events

Date Code Title Description
EEER Examination request
MKEX Expiry

Effective date: 20130211