Synchronous Online Monitoring of Rotational Speed and Temperature for Rotating Parts in High Temperature Environment

Rotational speed and temperature measurements of an engine blade surface play a vital role in the performance detection of an engine. We proposed a wireless passive LC sensor based on thick-film integration technology to integrate the sensor in situ on the surface of the rotating part, which can be used to monitor the rotational speed and temperature of the rotating part. The reflection signal generated by the impedance mismatch is output in the form of voltage through the detection circuit such that the synchronous online measurement of rotational speed and temperature is realized by analyzing the time slot of adjacent troughs and the amplitude of the output voltage. In addition, we used laser drilling, screen printing, high-temperature sintering, and other technologies to integrate the sensor in situ on the surface of the ceramic turntable, which is lightweight. Finally, the test was conducted by setting up a rotational speed-high-temperature composite experimental platform, and the results showed that the sensor can work normally in the range of 25-830°C, and the rotational speed measurement range was 50-400rpm. The consistency of the rotational speed measurement was suitable, the maximum error was less than 1%, and the work was stable within 180 min.