US Patent 11060992 Probe heater remaining useful life determination

A probe system includes a heater and a control circuit. The heater includes a resistive heating element routed through the probe. An operational voltage is provided to the resistive heating element to provide heating for the probe. The control circuit is configured to provide a test voltage different than the operational voltage and monitor a test current generated in the resistive heating element while providing the test voltage. The control circuit is further configured to detect micro fractures in the resistive heating element based on the test current.