Based on your previous focus on hot runner thermocouple temperature measurement and installation, the RMS value detection method for hot runner sensor signals is as follows:
1. RMS Thermoelectric Potential Signal Detection: A high-precision millivolt-level acquisition circuit is used to sample the weak thermoelectric potential signal output by the thermocouple throughout its entire lifecycle. Digital filtering eliminates electromagnetic interference noise from the industrial environment, and the true RMS thermoelectric potential value is calculated, avoiding signal distortion caused by noise interference.
2. RMS Resistance Signal Detection: A constant current source excitation method is used, applying a very small constant current to avoid self-heating interference. High-precision AD sampling acquires the voltage signal across the sensor, and Ohm's law is used to convert it into the true RMS resistance value, eliminating numerical deviations caused by contact resistance and line impedance.
After detection, the RMS value can be compared with a standard calibration table to quickly determine whether the sensor is in normal working condition.
