Abstract: An optical cavity for a Non-Dispersive Infrared gas sensor has invented comprising two oppositely arranged parabolic mirrors having common focus located on the common optical axis of the parabolic mirrors, and a plane mirror arranged along the optical axis between the vertex of each of the parabolic mirrors. The NDIR gas sensor has an extended optical path to increase precision and accuracy in the measurement, and substantially increased ventilation opening size to facilitate in and out of the target gas through the optical cavity thereby decreasing the response time required for measuring the gas concentration. The sensors based on the principal of Non-Dispersive Infrared Detection is used the light-absorbing characteristic of gases to measure the amount of light absorption that occur at the specific wavelength absorbed by a target gas and calculate the target gas concentration.

Abstract: A unique optical cavity for NDIR gas sensor module and test results for the CO2 concentration from 100 ppm to 2,000 ppm are disclosed. The proposed sensor module shows the maximum peak voltage at 500 ms pulse duration, however, it has a maximum fractional voltage changes at 200 ms pulse duration with 18,000 times amplification gain. From 100 ppm to 2,000 ppm, the voltage difference of sensor module (V) is 200 mV at 200 ms pulse duration and 3 sec. turn-off time.

Abstract: A unique optical cavity for NDIR gas sensor module and test results for the CO2 concentration from 100 ppm to 2,000 ppm are disclosed. The proposed sensor module shows the maximum peak voltage at 500 ms pulse duration, however, it has a maximum fractional voltage changes at 200 ms pulse duration with 18,000 times amplification gain. From 100 ppm to 2,000 ppm, the voltage difference of sensor module (V) is 200 mV at 200 ms pulse duration and 3 sec. turn-off time.