Research on High-Precision Oxygen Partial Pressure Sensor Based on TDLAS Technology

Aiming at the demand of oxygen partial pressure measurement in aerospace and aviation, a tunable diode laser absorption spectroscopy (TDLAS) technique is proposed to realize the oxygen partial pressure measurement. The wavelength modulation is used to drive a 763-nm vertical cavity surface emitting laser (VCSEL), and after multiple reflections from an optical absorption cell, the amplitude of the second harmonic is extracted by a lock-in amplifier to achieve oxygen partial pressure measurement. The experimental results show that the oxygen partial pressure measurement range of 0–50 kPa is achieved within the temperature range of 0 °C–40 °C, the maximum deviation of the measurement is less than 1 kPa, the maximum temperature drift is less than 0.06% FS/°C, and the 150-h stability is better than 0.1% FS/150 h.