earticle

영어

In this paper, the technology of QEPAS was used to detect the concentration of carbon monoxide gas. The regulation of DBF laser’s input current frequency and temperature was made first, current modulation frequency being 0 f  f / 2 16420HZ (frequency modulation is half of the resonance frequency of the QTF) and operating temperature being T=23 degrees Celsius. Then enable the output wavelength to be near 1.567 μm and measure CO gas of different concentrations. Through the analysis of the relationship between the second harmonic signals of different concentration CO gas, it is found that between CO concentration and the second harmonic intensity exists good linear relationship and that the system has no independence on the incident light wavelength and has high sensitivity and large dynamic measurement range. The study provides a new way of thinking for other types of trace gas detection and can be applied to the detection of automobile exhaust emissions.