Thermocouple open circuit detection with tone frequency signal application and spectral analysis

摘要

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 component of a tone signal across the thermocouple. If the amplitude of the particular frequency component exceeds a predetermined threshold, an output is provided for indicating an open circuit condition for the thermocouple.