The apparatus uses 880 , 950nm nir led as light source , interference filter as homochromy device , si photronic as detector . digital signal comes from ad transformation , processed by microprocessor system 以880 、 950nm的近紅外led為光源, 14個窄帶干涉濾光片為單色器,以硅光電池為檢測器,經(jīng)ad轉(zhuǎn)換得到數(shù)字信號,送單片機(jī)處理。