A penetrating remote temperature measurement device based on magnetic nanoparticles for measuring the internal temperatures of metal containers

摘要

A method for remote measurement of the temperatures of metal containers using magnetic nanoparticles (MNPs) is described. A differential structure composed of three inductors with iron cores was used to counteract the effect of the magnetic permeabilities of metal and air on the inductance. The change in inductance caused by the change in the temperature of MNPs attached either to the surface of or within a metal container was calculated from the output voltage amplitude of an AC bridge. The temperature of the object was then calculated from the AC-temperature model for the MNPs. The temperatures of the bottom and inside of a stainless-steel pot was measured by the proposed method within an accuracy of 2 K in the temperature range from 320 K to 400 K.