On-line measurement of combustion temperature based on TDLAS wavelength modulation technique

The thermometry of tunable diode laser absorption spectroscopy(TDLAS) wavelength modulation spectroscopy (WMS) technique was briefly introduced. Two adjacent water lines at 1 397.75 nm and at 1 397.87 nm were selected, and the on-line measurement system of WMS technique for CH4/air premix flame temperature was established. A 250 Hz real-time readout rate was achieved by using a multifunctional data acquisition card for signal processing and diode laser control. The measurements were performed on the calibration burner, and the A type standard uncertainty of temperature was less than 53 K base on the analysis of the measurement results.