高压环境下2种NDIR型CO_(2)红外传感器的响应规律

目的研究压力变化环境对NDIR型CO_(2)气体传感器的影响,获得不同压力范围内传感器的响应变化规律。方法采用小型加压舱,在CO_(2)分压不变的情况下,分别采用N_(2)阶梯缓慢加压和冲击快速加压方式,研究英国C20和国产G4传感器在高压环境中稳定时间和漂移度等性能指标的波动规律,考察传感器对压力变化的响应规律。结果在低于607950 Pa的高气压稳压状态下,基本不会造成机械损伤,但信号会发生较大的漂移,国产G4分体式传感器出现信号震荡现象。CO_(2)分体式传感器及整机的浓度输出值随着压力的升高,标准气样值与实测值的比值接近幂函数形式,分体式传感器的输出浓度值比整机的输出浓度值要大。结论不同CO_(2)浓度分压下的压力响应规律具有比较良好的一致性,冲击加压的漂移比阶梯加压显著,浓度真值可以通过测量总压和内置多次函数来修正。

Response Law of Two Kinds of NDIR CO2 Sensor in Hyperbaric Environment

The influence of pressure-changing environment on NDIR CO2 gas sensor was studied by using a small pressurized chamber, and the response variation law of the sensor in different pressure ranges was obtained thus. Under the condition of constant partial pressure of CO2, N2 static slow pressurization and impact fast pressurization were used respectively to study the fluctuation law of such performance indexes as stability time and drift of the two sensors, one is the C20 sensor made in Britain and the other is G4 sensor made in China The response law of the sensor to the changes of pressure and temperature was investigated, and the pressure compensation scheme under high pressure was proposed. When the pressure was lower than 60 meters, the mechanical damage did not occur but the signal drifted greatly. G4 sensor had a phenomenon of signal oscillation. The concentration output value of the two CO2 sensors and the whole machine increased with the pressure, and the ratio of the standard gas sample value to the measured value was close to the form of power function, besides, the output concentration value of the two sensors was larger than that of the whole machine. In conclusion, the pressure response law under different partial pressure of CO2 concentration shows good consistency. The signal drift of sensor under impact fast pressurization is more significant than that of N2 static slow pressurization. Moreover, the true value of concentration can be corrected by measuring total pressure and built-in multiple functions.