A measuring system and a method for operating it to detect wire breakage based on the measured current or voltage in which the impedance of at least a first sensor is measured and the result transmitted to a connected system. The invention is capable of detecting wire breakage and sensor failure in temperature sensor systems simultaneous with the temperature measurement by the measuring system comprising an AC current source which generates an AC current that is transmitted through the wires, and through at least the first sensor, measuring system analyzing changes in the phase angle between the current and voltage of the AC signal. If the difference in the frequency of the signal affecting the impedance or voltage of the sensor, and the frequency of the injected wire testing signal is sufficiently high, it is possible to distinguish between the first measuring signals and the second wire testing signal.

An apparatus for testing a thermocouple contact comprises a first nondestructive connector removably connected to a known contact of a thermocouple contact assembly and a second nondestructive connector removably connected to an unknown contact of the thermocouple assembly. A processing device is electrically connected to the first nondestructive connector and the second nondestructive connector. Responsive to connection of the thermocouple contact assembly between the first nondestructive connector and the second nondestructive connector and application of a heat source to the thermocouple contact assembly a Seebeck voltage is measured by the processing device.

A system for detecting a failure in a thermocouple array may comprise the thermocouple array. The thermocouple array may comprise a plurality of thermocouples. The system may comprise an impedance determination circuit. The impedance determination circuit may include a capacitor that has a capacitance equal to an expected capacitance of one of the plurality of thermocouples. The one of the plurality of thermocouples may be connected to test nodes of the impedance determination circuit. The system may comprise a comparator circuit connected to the impedance determination circuit, where the comparator circuit includes an amplifier and a comparator. The system may comprise an excitation circuit connected to the impedance determination circuit, where the excitation circuit includes a waveform generator and an amplifier.

A system for detecting a failure in a thermocouple array may comprise the thermocouple array. The thermocouple array may comprise a plurality of thermocouples. The system may comprise an impedance determination circuit. The impedance determination circuit may include a capacitor that has a capacitance equal to an expected capacitance of one of the plurality of thermocouples. The one of the plurality of thermocouples may be connected to test nodes of the impedance determination circuit. The system may comprise a comparator circuit connected to the impedance determination circuit, where the comparator circuit includes an amplifier and a comparator. The system may comprise an excitation circuit connected to the impedance determination circuit, where the excitation circuit includes a waveform generator and an amplifier.