| 摘要 |
<p>A self-calibrating infrared (IR) sensing device having the capability to measure the attenuation effects of surface contamination on the transmission window and to adjust the gain of the sensor accordingly so as to counter the attenuation. The IR sensing device includes an IR sensor mounted in a housing having an IR transparent window that allows IR radiation originating from outside the housing. The unit measures the increase in temperature and generates a proportional electronic signal. An IR radiator is also included. When activated, the radiator emits IR radiation that passes through the window and is lost to the outside if there is no contamination, or is alternatively reflected by an external mirror onto the sensor. If the surface of the window is contamined, the radiation raises the temperature of the contaminants. This increase in temperature results in a return signal.</p> |
