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Publication numberUS2076188 A
Publication typeGrant
Publication dateApr 6, 1937
Filing dateJun 22, 1934
Priority dateJun 22, 1934
Publication numberUS 2076188 A, US 2076188A, US-A-2076188, US2076188 A, US2076188A
InventorsThorleif Thorsten
Original AssigneeThorleif Thorsten
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Sampling device
US 2076188 A
Abstract  available in
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Claims  available in
Description  (OCR text may contain errors)

T. THORSTEN April 6, 1937.

SAMPLING DEVICE 2 Sheets-sheaf 1 Filed June 22,

A I flaw April 6, 1937.

Tv THORSTEN DEVICE SAMPLING Filed June 22, 1934 2 Sheets-Sheet 2 INVENTOR Patented Apr. 6, 1937 UNITED STATES PATENT OFFICE 15 Claims.

This invention relates to the sampling of lump material, such as coal, ore and the like and, more particularly, to a combined sample crushing unit, divider, and sample pulverizing unit.

In my Patent No. 1,890,199, dated December 6, 1932, I have shown a sample selecting device for taking a sample from a stream of falling material, and discharging it into a crusher. The present invention pertains to the treatment of the sample after it has been received in the crusher. In the sampling of coal, for instance, the coal comprises not only lumps of various sizes, but also a considerable amount of fines. To properly sample the coal, the sample should contain representative amounts of both the lumps and the fines. By running all of the sample material which is taken from the falling stream by a sampling mechanism as disclosed, for instance, in my patent above referred to, through a crusher,

0 the lump material is reduced to a size where it can be conveniently handled. However, in order to take in the large lumps as well as the smaller lumps and the fines, the sampling device necessarily has to take in a relatively large amount of a material with each sampling operation. In order that the sampling may accurately disclose the run of the material, this sample selecting must also be done quite frequently. This means that a very considerable mass of material has to be run through the crusher.

After the material has been crushed and reduced to a size where it can be conveniently handled, it is customary to make two kinds of tests. One of these pertains to the determination of the approximate moisture content, if the material under test is fuel. The other is the determination of the B. t. u. and ash content of the fuel. For the purpose of the first test, i. e., the moisture content, it is desired that the material be subjected to as little preliminary treatment as possible in order to avoid evaporation of the moisture. For the making of the second test, it is desired that the fuel be reduced to a pulverized state, but that the pulverized material shall be representative of all the fuel, both the original coarse material and lumps, and the fines. According to the present invention it is obviously not practical to utilize all of the material that is received from the sampling device and run 50 through the crusher for the making of these two tests. According to the present invention, there is provided a quartering or dividing means operating with the crusher, together with a pulverizer operating with the crusher, the quartering device and the pulverizer being so arranged that only a relatively small proportion of the total amount of material discharged from the crusher will ultimately be collected in the sample containers for the pulverized material, but that such material that does go into thesample containers will be truly representative of all of the material, both coarse and fines which is originally discharged into the crusher. Moreover, the present invention contemplates means whereby a fraction of the total material passing through the crusher may be collected without being pulverized, in a separate container, closed against the circulation of air. This second fraction of material may be used for the determination of the moisture content. Moreover, air crushers have been provided heretofore with means for taking a sample 01' the material crushed. The arrangement has been such that the sample has always been taken from one fixed point in the discharge of the crusher. According to the present invention, it is contemplated that the sample shall be extracted progressively around the entire discharge of the crusher. Much more satisfactory and accurate results are thereby obtained. I

The invention may be readily understood by reference to the accompanying drawings, in which Figure 1 represents a view partly in side elevation and partly in section, of a unit embodying my invention;

Figure 2 is an end elevation at right angles to Figure 1 of the same unit;

Figure 3 represents a vertical section through a slightly modified form or unit;

Figure 4 is a detail view of one of the dividing or quartering cones comprising a part of the mechanism; and

Figure 5 is a detail view representing a section substantially in the plane of line V-V of Figure 4, showing in detail a portion of the cone.

Referring to the drawings, 2 designates a foundation over a receiving pit (not shown) and into which excess sample material may be discharged. Supported on the foundation 2 is a casing 3 having a top 4. Supported on the top 4 is a cylindrical housing 5 of a standard crushing unit of the coffee mill type, this housing containing a corrugated sleeve 6 of the type commonly used in rotary crushing mills. At the top of the housing 5 is a casing 1 which is hinged at 8 so that one part of it may be open with respect to the other part. The casing I is provided at its top with a flanged opening 9 into which material may be discharged from a sample collector or from a. chute (not shown). The sample collector may all) be of the type disclosed in my said Patent No. 1,890,199.

Within the casing is a rigid spider I 8 that supports a combined housing and bearing structure II. The housing and bearing structure II has a horizontal bearing I2 for the drive shaft I3. The drive shaft I3 extends through the casing I. I have shown it as being provided with a multiple belt pulley whereby it may be driven by a motor I4 through belts I5. Obviously, any other suitable driving arrangement may be substituted. On the inner end of the shaft I3 is a mitre gear I6. The mitre gear I6 meshes with a horizontal gear IT on the end of a Vertical shaft I8 which vertical shaft passes through a bearing I 9 in the combined housing and bearing portion II, the gear I! being keyed or otherwise secured to the shaft to turn it. This gear is retained in place by means of a nut II. The housing includes a removable cast iron hood 20, the hood being in the shape of a cone so as to distribute the material which falls onto the top of the housing in all directions around the housing I I. This arrangement provides a housing which distributes the material falling into the casing I and also a dust guard which prevents both lump material and dust from getting into the gears I6 and I! and into their respective bearings. The shaft I8 extends centrally down through the cylindrical casing 5 and depends for a distance considerably below the casing 5. Keyed to the shaft I8 so as to rotate therewith is a corrugated cone member 2| of the type used in a coffee mill type of crusher, the member 2I being arranged for cooperation With the fixed member 6.

The casing 5 extends slightly below the portion 6 so as to provide an annular wall at 22 close to the lower edge of the revolving cone member 2I. The material which is crushed in the mill is frequently discharged with considerable force in a horizontal direction, and the annular portion 22 serves to obstruct the free movement of such material and direct it downwardly. The location of the annular wall 22 close tothe space 23 between member 2I and the bottom of the member 6 is quite important to the securing of respective sample material as will be hereinafter more fully described. To this extent, the constructions shown in Figures 1 and 2 are the same as the construction shown in Figure 3, and the same reference numerals have been used to designate the corresponding parts. However, the sample quartering arrangement shown in Figure 1 is slightly different from that shown in Figure 3, and the arrangement shown in Figure 1 will now be described. Carried on the shaft I8 and keyed or splined thereto to turn with it below the unit 2I is a hollow conical member 24, the exterior of which is shown in detail in Figure 4. This cone is provided with one or more openings 25 therethrough, two such openings being shown. Looking at Figure 4, it may be assumed that the cone moves in a counter-clockwise direction in the operation of the unit. On the leading side 5 of the opening 25 there is a vertically extending flange member 26 having a base portion 21 which rests on the surface of the cone and which is provided with slots 28. Bolts 29 passing through the slots and through the cone are provided for 7 holding the member 26 in place. By reason of the arrangement of the slots, the member 26 with its flange 21 can be adjusted to different positions over the opening 25 to thereby vary the effective size of the opening 25. 75 The opening 25 preferably has its sides radial,

and the flange 26 is set so that it may be maintained in a radial position. The flange member 26 has a rearwardly extending end flange portion 26a at the outer end thereof and a shorter flange portion 26b at the inner end thereof. At the other radial edge of the opening 25 there is an upstanding flange member 30. It has a forwardly projecting end flange portion 30a which cooperates with the flange portion 26a of member 26 and a forwardly extending flange portion 30b which cooperates with the flange portion 26b of the member 26. The members 26 and 30 form radial walls for the opening 25 while the overlapping flanges 26a and 30a and the overlapping flanges 26b and 38b form end walls around the opening 25. The wall 30 at the trailing side of the opening is higher than the wall or flange 26 at the leading side of the opening. As shown in Figure 1, the edge of the flange 30 terminates in relatively close proximity to the horizontal internal shoulder 32 forming a part of the base of the casing or housing 5. The member 30 is preferably not adjustable, a willcient range of adjustment being provided by the member 26.

At the base portion of the crusher housing 5, there is a depending skirt or flange 33, the diameter of which is considerably larger than the diameter of the portion 22, the shoulder 32 being formed beween these two portions of the crusher casing.

Below the cone 24 there is an inverted conical hopper 34, the upper edge of which terminates just below the lower edge of the cone 24, there being a very slight clearance space between these two cones. The cone 34 is supported on a spider 35 from a structure 36 suspended from the base of the housing 5 for the crusher. At the center of the hopper 34, there is a crusher throat 31 toward which material falling into the cone 34 gravitates. Carried on the shaft I8 and keyed thereto to turn with it is a cone member 38 which is corrugated for cooperation with the throat 31, the portions 37 and 38 forming a crushing and pulverizing mill of the coffee mill type. The hopper 34 is stationary, while the member 38 being carried on the shaft I8 rotates with the shaft I8.

Secured to the base of the member 34 is a spider member 39 having a plurality of openings 40 therethrough. It is provided on a central hub 4I thereof with a double clip 42 for receiving two containers, which may be ordinary glass Mason jars 43, these jars being held diametrically opposite each other, and being held under the openings 40. At the lower end of the shaft I8 there is an adjusting nut 44 which operates against a sleeve 45. This sleeve in turn bears against the crusher cone member 38 so that by adjustment of the nut 44, the cone 38 can be adjusted to vary the grinding action thereof and to take up for wear which develops in the grinding surfaces. Likewise, the top of the shaft I8 is provided with an adjusting nut I'I'. By screwing down on the nut I 'I', and loosening up on the nut 44, the shaft I8 may be raised. The shaft I8 is provided with a shoulder 46 to lift the grinding cone 2| of the main crushing mill.

Located at one side of the member 34 is an inclined chute 41, the upper end of which terminates close to the lower edge of the cone 24 and the lower end of which passes through an opening in the cover 48 of a bucket or other removable receptacle 49. 50 designates a gate member in the form of a curved angle bar adthe material during the time the opening is passjustably secured across the upper end of the chute 41. As shown in Figure 2, the gate member 50 is provided with an elongated slot so that it can be adjusted in a horizontal direction by loosening up on the bolt which holds it in place. By moving the member 50 to the left as viewed in Figure 2, the effective opening of the chute 41 is lessened, while by adjusting this member 50 to the right the effective area of the opening of the chute 41 can be increased. This is adjusted in operation to the proper extent, for receiving a certain amount of sample material.

In the operation of the unit, the shaft I8 is driven through the driving means shown for operating the crusher. The sample material comprising large lumps, small lumps, coarse particles and fines, all discharges into the hopper I at the top of the main crusher and discharges down into the crusher where all of the lumps are broken up and where all of the fines and the particles below a certain size sift through without being crushed. The crushed material, as well as the fines, discharges from the grinding mill around the annular space 23. Some of the material, particularly the harder material, flies out with considerable force. This impinges against the wall 22 and is deflected downwardly. Due to the manner in which the sample material falls into the crushing unit, and due to various other causes, more of the fines may discharge at one point or portion of the space 23 than at other points or portions. In the operation of any mill, it can be easily observed that the same character of material does not discharge from every point around the periphery of the rotating crushing member.

With the present invention, the cone 24 rotates with the crusher. The material continuously falls through the opening 25. The opening 25 is continuously moving around the bottom of the crushing mill. The material which falls onto the surface of the cone 24 is discarded, except the small portion which falls down the chute 41. The portion that falls through the opening 25 is only a small fraction of the total amount of the material ground, but because of the fact that the opening 25 moves around the bottom of the crushing mill, it collects sample material from all parts of the mill to an equal extent. In this respect, the sample taken is more representative and satisfactory than with sampling crushers heretofore obtained, where the sample is taken always at the same place in the curtain of material discharging from the crusher. The upstanding walls 26 and 30, together with the end walls which they provide for the opening 25, serve to limit the portion of the sample being passed through the opening 25 to a very definite portion of the annular curtain or circular stream of material that is falling from the bottom of the crushing unit. The difference in height between the leading edge 25 and the trailing edge or flange 30 is roughly proportioned to take care of the distance which the falling stream covers in the time which it takes for the opening to move through an arc corresponding to the size of the opening. That is to say, a certain time interval elapses between the instant when the flange 26 passes a given point in its circular travel, and the flange 30 passes the same point. During this time interval that portion of the curtain of material which is between these two flanges moves down a certain distance. Therefore, by making the trailing wall higher than the leading wall, the quartering device takes care of the fall of ing any particular point, and the sample selected more accurately represents a true sample through the falling curtain of material at one point than it would if both walls were of equal height or if no walls were provided at all.

The material which passes through the opening 25, as above stated, represents only a small fraction of the total amount of sample material passed through the crusher, but it accurately represents a true fraction of every portion of the material that falls through the crushing unit. This fraction of material is received in the hopper 34. It is pulverized between the members 3'! and 38 and the pulverized material falls through the openings 40 in the spider 39. The jars 43 cover only a portion of the openings 40 so that of all of the material which passes between the members 31 and 38, the jars receive only a fraction of this material. The pulverizing mill operates at the same speed as the main crushing mill and simultaneously therewith. The three devices, 1. e., the main crushing device, the quartering device and the pulverizing device all operate in unison. This assures that the fraction of material passing through the quartering device is crushed at the rate necessary to keep up with the fresh material coming in, and the entire unit provides a proportionate sampling device in which a true fraction of every sample which falls into the main crushing unit ultimately reaches the sample collecting jars 43. In the case of fuel produced by a mine for shipment to a power house where the B. t. u. and ash content is guaranteed by the producer, it is contemplated that one of the two jars 43 may be kept by the coal-producing company and the other be sent to the power house. Each one is properly labeled with the period over which the sample is taken. In the case of any controversy, each party has exact samples of the material.

The arrangement shown in Figure 3 is essentially similar to the construction heretofore described and corresponding reference numerals have been used to designate the corresponding part throughout. In the modification shown in Figure 3, however, provision is made for an additional quartering device between the upper cone 24 and the hopper 34 of the second grinding unit. To this end, the shaft I8 is provided with a second cone keyed thereto below the first cone 24. The second cone 55 is keyed to the shaft [8 so that it will rotate therewith. This cone is provided with an opening 56 and an adjustable gate 51 similar to the corresponding gate of the upper cone member. The opening 56 registers substantially with one of the openings in the upper cone member. In the arrangement shown in Figure 3, there is a hopper 5B which is above the cone 55 and below the cone 24 and this hopper receives the material that falls through the openings in the upper cone 24 and directs it down onto the lower cone 55. The hopper 58 is stationary. The under surface of the cone 24 is provided with webs 59 (see Figure 4) which sweep around on the inside of the hopper 58, deflecting the material that falls through the hopper and dislodging any material that does not fall by gravity.

Material which falls through the opening 56 is received in the hopper 34 of the second crushing unit. Material which does not pass through the opening 56 falls for the most part into the casing 3 while a small amount of it may be deflected into the receiver 49 through the chute 41 as previously described in connection with Figure 1. The hopper 58 is supported on a spider 58a so that material which falls off of the top of the cone 24 can drop down without falling onto the cone 55. It would appear at first glance that the second deflector cone 55 has very little utility, since it rotates with the deflector 24 and at the same speed as the deflector 24. It would appear, moreover, that the material which would fall into the hopper 34 through the opening 56 would merely be such material as would fall through the opening in the cone 24 which is immediately above the opening 55. More accurate sampling, however, can be secured by letting a relatively large amount of material fall through the openings in the cone 24 and a relatively lesser amount of material fall through the opening 56, than where the arrangement shown in Figure 1 is provided.

While I have shown and described certain present preferred embodiments of my invention, it will be understood that various changes and modifications may be made therein within the contemplation of my invention and under the scope of the following claims.

I claim:

1. A sampling apparatus comprising a crushing unit having inner and outer concentric crushing members, a drive shaft on which the inner member is carried and through which it is rotated relatively to the outer member, said crusher having an annular discharge between the two members, a sampling device under the crusher onto which the material discharged from the crusher falls, said sampling device being carried on said shaft to rotate with the inner member of the crusher, the sampling device being thereby adapted to progressively remove sample material from around the annular discharge.

2. A sampling crusher unit comprising inner and outer concentric members, a central drive shaft, the inner member being carried on said drive shaft for rotation relative to the outer member, the crusher having an annular discharge for crushed material around the bottom of said inner member, a sampling cone under the crusher carried on said shaft for rotation with said inner member and onto which material discharging from the crusher falls, said sampling cone having an opening therein, and means under the cone for receiving the material that passes through the opening.

3. A sampling crusher unit comprising inner and outer concentric members, a central drive shaft, the inner member being carried on said drive shaft for rotation relative to the outer member, the crusher having an annular discharge for crushed material around the bottom of said inner member, a sampling cone under the crusher carried on said shaft for rotation with said inner member and onto which material discharging from the crusher falls, said sampling cone having an opening therein, means under the cone for receiving the material that passes through the opening, and means on the outer member of the crusher projecting below the inner member and forming an annular wall around said annular discharge and positioned to deflect laterally moving particles onto the cone.

4. A sampling crusher unit comprising inner and outer concentric members, a central drive shaft, the inner member being carried on said drive shaft for rotation relative to the outer member, the crusher having an annular discharge for crushed material around the bottom of said inner member, a sampling cone under the crusher carried on said shaft for rotation with said inner member and onto which material discharging from the crusher falls, said sampling cone having an opening therein, means under the cone for receiving the material that passes through the opening, and vertically extending wall members on the cone at each side of the opening extending well above the surface of the cone and being adapted to prevent material which falls onto the cone from bouncing or sliding into said opening.

5. A sampling crusher unit comprising inner and outer concentric members, a central drive shaft, the inner member being carried on said drive shaft for rotation relative to the outer member, the crusher having an annular discharge for crushed material around the bottom of said inner member, a sampling cone under the crusher carried on said shaft for rotation with said inner member and onto which material discharging from the crusher falls, said sampling cone having an opening therein, means under the cone for receiving the material that passes through the opening, and vertically extending wall members on the cone at each side of the opening extending well above the surface of the cone and being adapted to prevent material which falls onto the cone from bouncing or sliding into said opening, the wall on the leading side of the opening being lower than the wall on the trailing side of the opening.

6. A sampling crusher unit comprising inner and outer concentric members, a central drive shaft, the inner member being carried on said drive shaft for rotation relative to the outer member, the crusher having an annular discharge for crushed material around the bottom of said inner member, a sampling cone under the crusher carried on said shaft for rotation with said inner member and onto which material discharging from the crusher falls, said sampling cone having an opening therein, means under the cone for receiving the material that passes through the opening, and vertically extending wall members on the cone at each side of the opening extending well above the surface of the cone and being adapted to prevent material which falls onto the cone from bouncing or sliding into said opening, the wall on the leading side of the opening being lower than the wall on the trail- 0 ing side of the opening, one of said wall members being movable toward and away from the other.

'7. A sampling unit comprising an upper crushing unit of relatively large capacity, a lower crushing unit of relatively small capacity, means for operating both units together, quartering means operatively interposed between the upper and lower units, and means intermediate the upper and lower crushing units for collecting a portion only of the material which is passed through the first crushing unit and which has been deflected away from the second crushing unit by said quartering means.

8. A sampling unit comprising an upper crushing unit of relatively large capacity, a lower crushing unit of relatively small capacity, means for operating both units together, quartering means operatively interposed between the upper and lower units, and means intermediate the upper and lower crushing units for collecting a portion only of the material which is passed through the first crushing unit and which has been deflected away from the second crushing unit by said quartering means, said means comprising a receptacle closed against a free circulation of air therethrough, and other receiving means for receiving material which is discharged from the second crushing unit.

9. A sampling apparatus comprising an upper crushing unit, a lower crushing unit directly below the upper one, a common drive shaft for both units, driving means for operating the shaft, and. quartering means carried by the drive shaft and operatively interposed between the upper and lower crushing units, said quartering means being adjustable to vary the relative amounts of material directed into the lower unit from the upper one.

10. A sampling apparatus comprising an upper crushing unit, a lower crushing unit directly below the upper one, a common drive shaft for both units, driving means for operating the shaft, quartering means carried by the drive shaft and operatively interposed between the upper and lower crushing units, said quartering means being adjustable to vary the relative amounts of material directed into the lower unit from the upper one, and means cooperating with the quartering means for receiving a portion only of the material that has passed through the first crushing unit and which has been deflected away from the lower crushing unit, said means including a receiving chute and a receptacle into which the chute discharges, and an adjustable gate for said chute.

11. Apparatus for sampling material, comprising an upper hopper having a crushing unit at the bottom thereof, a second crushing unit below the first, each crushing unit having a stationary part and a rotatable part, a common vertical drive shaft on which the rotatable parts of both units are carried, driving means in the upper hopper operatively connected with such shaft, said driving means having a dust-proof housing therefor, said housing having a conical top, and quartering means operatively interposed between the upper and lower crushing units for causing a small percentage only of the material which is crushed in the first unit to be deflected into and be passed through the second unit.

12. Sampling apparatus comprising an upper crushing unit, a lower crushing unit, each of said crushing units having a stationary part and a rotatable part, a common drive shaft on which the rotatable parts of both units are carried, means for driving said shaft, and a quartering cone carried on said shaft above the lower crushing unit and below the upper crushing unit, said quartering cone rotating with the rotatable part of the upper crushing unit and having an opening therethrough through which material discharged fromv the upper crushing unit can fall through said cone, said opening extending over a relatively small portion only of the surface of said cone.

13. Sampling apparatus comprising an upper crushing unit, a lower crushing unit, each of said crushing units having a stationary part and a rotatable part, a common drive shaft on which the rotatable parts of both units are carried, means for driving said shaft, a quartering cone carried on said shaft above the lower crushing unit and below the upper crushing unit, said quartering cone rotating with'the rotatable part of the upper crushing unit and having an open- E ing therethrough through which material discharged from the upper crushing unit can fall through said cone, said opening extending over a relatively small portion only of the surface of said cone, and a gate for controlling the effective size of said cone.

14. Sampling apparatus comprising an upper crushing unit, a lower crushing unit, each of said crushing units having a stationary part and a rotatable part, a common drive shaft on which the rotatable parts of both units are carried, means for driving said shaft, and a quartering cone carried on said shaft above the lower crushing unit and below the upper crushing unit, said quartering cone rotating with the rotatable part of the upper crushing unit and having an opening therethrough through which material discharged from the upper crushing unit can fall through said cone, said opening extending over a relatively small portion only of the surface of said cone, said cone having upwardly extendin walls at each side of the opening, the leading wall with reference to the direction of rotation of the cone being lower than the wall at the trailing side of said opening.

15. Sampling apparatus comprising an upper crushing unit, a lower crushing unit, each of said crushing units having a stationary part and a rotatable part, a common drive shaft on which the rotatable parts of both units are carried, means for driving said shaft, and a quartering cone carried on said shaft above the lower crushing unit and below the upper crushing unit, said quartering cone rotating with the rotatable part of the upper crushing unit and having an opening therethrough through which material discharged from the upper crushing unit can fall through said cone, said opening extending over a relatively small portion only of the surface of said cone, the upper crushing unit having an annular vertical wall immediately below the discharge thereof against which material forcibly expelled from the crushing unit in a lateral direction is deflected downwardly against said cone.

THORLEIF THOLRSTEN.

Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US2636689 *Dec 7, 1949Apr 28, 1953Iowa State College Res FoundatSoil crushing or treating apparatus
US2963232 *Nov 28, 1956Dec 6, 1960Smith Eric SGrinder
US3098390 *Dec 22, 1960Jul 23, 1963Duval Sulphur And Potash CompaSampling device
US3939714 *Jun 10, 1975Feb 24, 1976The United States Of America As Represented By The United States Energy Research And Development AdministrationVariable percentage sampler
US4179929 *Jul 21, 1978Dec 25, 1979Redding James ATruck sampling system
US4679737 *Jun 12, 1986Jul 14, 1987Romer Labs, Inc.Grinding sub-sampling mill and method for preparation of test sample
US4946650 *Oct 13, 1989Aug 7, 1990Roethele SApparatus for integrating sampling and in-line sample splitting of disperse products from transport conduits or at flow transfer points
US4951511 *Jul 24, 1989Aug 28, 1990Noranda, Inc.Apparatus for sampling heterogenous material
DE1189292B *Oct 11, 1958Mar 18, 1965Westfalia Dinnendahl GroeppelProbenteiler
Classifications
U.S. Classification73/863.45, 241/162, 241/245, 241/101.2, 73/863.51, 73/863.56, 241/100
International ClassificationG01N1/20
Cooperative ClassificationG01N1/20
European ClassificationG01N1/20