Wireless Temperature Sensor Operating in Complete Metallic Environment Using Permanent Magnets

This paper presents the first wireless temperature sensor operating in a complete metallic environment using permanent rare-earth magnets. The sensor is based on change in magnetic field strength with temperature, which is detected using commercially available Hall Effect sensors. Temperature of a hot plate at a distance of 19 mm in air and through a 9.5-mm-thick nonmagnetic austenitic stainless steel plate is successfully detected from 5
^°
C to 80
^°
C as a proof-of-concept demonstration. The curve fit values show excellent response with R
²
value greater than 98% for both the cases.