Non-contact radiative temperature measurement of an object in a closed cavity

Referring to the wide application of non-contact surface temperature measurements, a method is presented here using the thermal noise in the microwave band of the measured object in a closed cavity. The thermal noise coupled from an antenna in this frequency range allows the measurement of the temperature within the object and even the core temperature. The measurement of the scattering parameters of the antenna in the cavity is needed to correct the coupled thermal noise power from the object. Using a mathematical algorithm, an online realtime temperature measurement can be achieved.