Wireless multi-temperature measurement for rotating cryogenic machines

A method of wireless and multitemperature measurement is proposed, in which the resonant frequency shift of the sensors caused by temperature is the detectable signal. LC resonant circuit sensors consisting of a ferrite yoke coil and a mica-type capacitance were used in the demonstration experiment. The experimental data show that the temperature of several points is discriminatively detectable in the rotating machine. The response time of the method for every measurement is about one minute to attain 10 mK resolution. It is believed that a frequency tracer technique for each sensor may be a way to improve the response time. However, the proposed measurement system should be restricted to the observation of the stationary temperature profile in a rotating cryogenic machine