Infrared Absorption Methane Detector With Environmental Parameters Compensation And Thermostatic Control Function

Methane not only exists in coal-bed methane, it is also the main component of natural gas, biogas and other important energy, and methane as an important chemical raw materials have been widely used in a variety of substances production process, so methane detectors are widely used in the industrial and mining fields. Infrared absorption methane detector due to with high stability,high precision, long life, less maintenance advantages, applications continue to expand. Therefore, the design of high reliability infrared absorption methane detectors is essential for the accurate detection of the concentration of methane in each field.The measurements of non-dispersive infrared absorption principle is susceptible to environmental parameters, on the one hand the temperature will affect the radiation characteristics of infrared light causing a change in the zero point and sensitivity, on the other hand pressure changes can affect the concentration of the test gas per unit volume resulting in measurement errors. In order to obtain accurate measurements, the paper proposes the specific environmental parameters compensation scheme. Compared to the method of mathematical modeling by the experimental data to complete the zero and sensitivity temperature compensation, from the fundamental factors affecting the measurement accuracy, the paper puts forward the thermostatic control scheme.By thermostatically control circuit powers the infrared light source, so that the temperature of infrared light source can be kept constant under any environmental condition, thus ensuring the radiation characteristics stable,eliminating the effects of ambient temperature on the measurement results. Theimpact of environmental stress on the measurement results is a linear relationship,and piezoresistive gas sensor is used for environmental pressure compensation. In the paper, completes the hardware and software design of infrared absorption methane detector with environmental parameters compensation and thermostatic control function.The paper made the theoretical analysis about the impact of environmental parameters on the infrared absorption principle, completed the hardware and software design of thermostat control and pressure compensation, and effectively eliminating the impact of environmental parameters on the measurement results.The experimental data shows, in a wide range of ambient temperatures and pressures, the detector has a higher stability and accuracy, can better meet the needs of industry and mining.