瓦斯气体电化学传感器超量程段的非线性自校正研究

Study of CH_4 Electrochemical Sensor Non-linear Self-correction in Extended Range

由于电化学传感器在超量程段的输出为曲线输出,测量误差范围较大。对此,提出了曲线拟合法来予以校正,为测量大浓度气体时出现的量程超限提供了一种解决方法,给出了校正原理及实验电路,测试得到瓦斯电化学传感器在其超量程段10000×10-6～12000×10-6范围内的一组输出电压数据,表明在超量程段已不具有线性特征。使用最小二乘法对数据做拟合处理后,得出了超量程段的二次拟合曲线,从而达到了非线性自校正的智能化。实验表明瓦斯气体电化学传感器量程扩大20%,扩大部分测量误差0.11%。

CH4 electrochemical sensor＇s output is curve,Which has a high test error in extended range.Introduces a method of the CH4 gas electrochemical sensor non-linear self-correction which is the curve fitting in extended range,designs the hardware circuits and equipment,tests a set of voltage data of CH4 gas electrochemical sensor in extended range from 10 000×10-6 to 12 000×10-6,indicates that the CH4 gas electrochemical sensor is non-linear in extended rang ,uses the least square method to fit the data,gets the quadratic fitting curve of extended range,offers the basis for the non-linear self-correction in intelligent instruments.Extends the CH4 gas electrochemical sensor rang up to 20% ,the error 0.11% .Supplies a method for the measurement of CH4 gas in extended rang using electrochemical sensor.