An improved open circuit detector for testing a thermocouple for an open circuit condition. The detector includes a generator for providing and sourcing a tone signal to the thermocouple, wherein the tone signal has a known frequency and amplitude. A monitor analyzes the amplitude of a particular frequency...http://www.google.com/patents/US5418464?utm_source=gb-gplus-sharePatent US5418464 - Thermocouple open circuit detection with tone frequency signal application and spectral analysis
