Development of an infrared sensor for on-line analysis of lubricant deterioration

It was an object of the presented study to develop an infrared sensor for on-line analysis of the deterioration stage of industrial lubricants. The sensor employs the effect of infrared absorption and Attenuated Total Reflection (ATR). The ATR technique provides the separation of sensitive sensor optics from the hazardous environment. A novel method of signal modulation permits measurements of absorptions at sample and reference wavelength, within one measurement cycle, using a simple one-element pyroelectric detector and Fourier Transform of the detected signal.