Tunable diode laser absorption spectroscopy can achieve simultaneous measurements of gas temperature, concentrations, and pressure of the combustion field. The wavelength modulated spectroscopy method can improve the signal-to-noise ratio of measurements in the harsh engine flow environment, but the signal demodulation time is long. After the experiment, a database of the integrated absorption area and 2f/1f maximum of the two spectral lines per unit length is established via the same absorption spectral, scan frequency and modulation frequency are used to traverse the temperature T, concentration χ and pressure P. For the subsequent the fast measurement of the combustion field parameters is achieved by comparing the experimental measurements with the database values at the same experiment. The results show that the database method requires 2.2h to process 1.5GB of experimental data with three channels and 4.6s measurement time, which is up to 7 times shorter than the traditional demodulation method.
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