THERMOCOUPLE OPEN-CIRCUIT DETECTION CIRCUIT AND METHOD
A method for detecting an open-circuit in an external thermocouple network includes these steps: (a) injecting a current pulse of a predetermined duration into the external thermocouple network; and (b) measuring the voltage across the pair of terminals after a time period following the predetermined duration. In one example, the time period is sufficiently long to allow the current pulse to dissipate from the external thermocouple circuit when a thermocouple in the external thermocouple network does not have an open circuit. The thermocouple network may include a resistor-capacitor network provided between the thermocouple and one of the terminals.
1 . An apparatus for detecting an open-circuit in an external thermocouple network, the thermocouple network providing a voltage across a pair of terminals, the apparatus comprising:
a current pulse generator configured to inject a current pulse of a predetermined duration into the external thermocouple network; and
a measurement circuit that measures the voltage across the pair of terminals, the measurement circuit being activated after a time period following the predetermined duration.
2 . The apparatus of claim 1 , wherein the thermocouple network comprises a resistor-capacitor network provided between the thermocouple and one of the terminals.
3 . The apparatus of claim 1 , wherein the time period is sufficiently long to allow the current pulse to dissipate from the external thermocouple circuit when a thermocouple in the external thermocouple network does not have an open circuit.
4 . A method for detecting an open-circuit in an external thermocouple network, the thermocouple network providing a voltage across a pair of terminals, the method comprising:
injecting a current pulse of a predetermined duration into the external thermocouple network; and
measuring the voltage across the pair of terminals after a time period following the predetermined duration.
5 . The method of claim 1 , wherein the thermocouple network comprises a resistor-capacitor network provided between the thermocouple and one of the terminals.
6 . The method of claim 1 , wherein the time period is sufficiently long to allow the current pulse to dissipate from the external thermocouple circuit when a thermocouple in the external thermocouple network does not have an open circuit.