Sensor the wire-free remote measurement of temperatures

摘要

The invention relates to a temperature sensor 10 for the wire-free measurement of temperatures or of physical variables which determine the temperature, having a resonant circuit 11 whose temperature-dependent resonant frequency is determined, characterized in that the temperature sensor has a coil which is built up by means of bimetal strips 23 and whose inductance and/or winding capacitance 21, 22 can be varied by the temperature- dependent deformation 33 of the bimetal strips. By means of a microcontroller 14 and digital/analogue converter, the frequency of the field in an adjustable tuned circuit 13 is swept over a range in which the temperature-dependent detuning of the sensor circuit 10 is located. The attenuation of the transmitter tuned circuit 13 is measured by means of the analogue/digital converter, converted into the corresponding temperature value and displayed 15. The measured values are available for further processing, for example in a control loop, via an interface 16. The sensor 10 and the housing 17 are designed to be watertight and airtight. IMAGE