Temperature compensated NDIR CH4 gas sensor with focused beam structure

Abstract

With concave mirror surfaces, the IR light has been focused into circular shape and the intensity of IR light on the detector side has been enhanced effectively. Based upon the simulation results, a new NDIR gas sensor has been prototyped with high efficiency. Using concave mirror surfaces, the output voltages of gas sensor are significantly increased about from 2.15 V (vertical mirror structure) to 3.62 V at 0 ppm CH4 concentration. After temperature compensation, the detection error has been reduced from 2000 ppm to less than 200 ppm within 15 °C to 35 °C.