Study on detection of hydrogen sulfide gas with double output ports

With the development of technology, the detection of hydrogen sulfide gas concentration not only requires simple operation, but also requires measurement range is large. In this research, an additional detection port is added on the basis of harmonic detection technology, and the two are used together. According to the different concentration of gas, the corresponding output port is selected as the detection port. When the gas concentration is low, the difference I1 between the output I and the constant 0.9I0 is selected, and the differential output I2f is detected at a high concentration. The output results of harmonic detection span the 5 orders of magnitude when the gas concentration from 0.001% to 40%. However, the output of this method takes only 2 orders of magnitude, and the measurement range is widened under the same range. When the input light intensity changes, the magnitude of the overall measurement value is changed and does not affect the magnitude of the magnitude.