采用双通道差分式红外气体检测方法, 基于比尔朗伯理论做针对性修正, 研制出低检测下限、高探测性能的手持式红外甲烷气体检测仪.通过TracePro光线模拟软件, 对比分析多种光学路径结构, 得到小空间内长光程气室结构, 增强气体有效吸收, 提高仪器检测性能.引入多参数补偿算法, 对气体吸收理论进行优化, 得到适应本检测系统的气体吸收函数, 以保证气体浓度信息计算准确性.仪器工作时最大输出电流为130 mA, 采用干电池供电, 仪器的尺寸为209 mm×70 mm×40 mm, 甲烷气体浓度爆炸限以下最低检测限可达到50 ppm, 可以保证气体防爆的安全性要求.

The dual-channel non-spectroscopic infrared gas detection method is adopted, and the traditional infrared gas absorption theory is modified to develop a handheld infrared methane detector with low detection limit and high detection performance. Through the light simulation software TracePro, a variety of optical path structures were compared to obtain the long-path gas chamber structure in a small space to enhance the effective absorption of gas and improve the detection performance of the instrument. The multi-parameter compensation algorithm is introduced to optimize the Lambert-Beer law, and the gas absorption function adapted to the detection system is obtained to ensure the accuracy of the calculation of gas concentration information. When the instrument works, the maximum output current is 130 mA, which is powered by dry battery. The size of the instrument is 209 mm×70 mm×40 mm. The minimum detection limit is below the explosion limit of methane gas concentration reaching to 50 ppm, which can ensure the safety of the gas against explosion.