摘要 |
Diagnostic circuitry of a process device is used to detect degradation of a resistive element of the process device while the process device remains online, without the use of an additional power source. In addition, once degradation of the resistive element is detected, the diagnostic circuitry can be compensated for automatically. The diagnostic circuitry includes a testing circuit and a processing system. The testing circuit is coupled to the resistive element and is configured to apply a test signal to the resistive element. The test signal heats the resistive element and causes the resistive element to generate a response signal. The processing system compares a change in the response signal to a corresponding reference to detect degradation of the resistive element.
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