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目前,甲烷气体检测器的原理主要有两大类,即纯物理原理(如光干涉、热导和声速等)和催化氧化原理。物理原理的仪器主要是利用甲烷的物理特性值与空气的物理特性值进行比较。由于这一比值很小(光干涉原理除外),因此在检测低浓度(<1%)的甲烷时,准确度较差,此外,受周围环境变化的影响较大、如温度、湿度和压力等。在检测低浓度甲烷时,还需要先除掉气样中的二氧化碳和水蒸汽。
At present, the principle of methane gas detector mainly has two broad categories, namely purely physical principle (such as optical interference, thermal conductivity and sound velocity, etc.) and catalytic oxidation principle. Physical principle of the instrument is mainly the physical properties of methane and air use the physical properties of the value of comparison. Because this ratio is small (except for the light interference principle), it is less accurate in the detection of low concentrations (<1%) of methane and, in addition, is more affected by changes in the surrounding environment such as temperature, humidity and pressure . In the detection of low concentrations of methane, but also need to get rid of gas samples of carbon dioxide and water vapor.