Prospects for industrial remote temperature sensing using microwave radiometry

Remote temperature sensing is increasingly important in the processing of semiconductors, chemicals, plastics, rubber, and other materials. Conventional infrared sensors cannot operate in environments where suspended particles such as vapor or dust scatter thermal radiation from the object. However, longer-wavelength microwaves are not scattered by particulates that scatter infrared rays. We have developed a low-cost X-band microwave radiometer which has demonstrated temperature sensing performance superior to infrared sensors in experiments designed to simulate typical industrial situations involving suspended particles. We present data that describes the conditions under which microwave temperature sensing is more accurate than infrared sensing.