US Patent 7208735 Process field device with infrared sensors

Infrared radiation from a plurality of locations associated with a process is measured by a field device, which includes a plurality of input channels, a plurality of IR sensors, and a data processor. The infrared radiation from the locations associated with the process is received by the input channels and the intensity of the infrared radiation is measured by the IR sensors to produce representative sensor signals. The data processor produces an output as a function of selected sensor signals.