一、概述DG-4型嗅敏检漏仪与其它气体检测仪器不同的是,采用了一种以SnO_2为主体的金属氧化物半导体作为检测元件,当元件与易燃易爆或有毒气体接触时,元件的电阻值发生急剧的变化,利用这个变化,把气体浓度转换为电量进行测量。仪器的检测部分是用一个对多种气体具有反应的广谱性元件。仪器的测量机构是一个电桥,电桥的指示与气体浓度之间有一定的关系。仪器内部还装有限量报警机构,当被测气体浓度超过某一预定放置的量限后,电桥输出推动射极耦合触发器翻转,接通声、光报警电路用警报声和闪光报警。为了给探头元件以恒定的工作温度,机内装有高效率的直流 I. Overview DG-4 type sniffing sensitivity leak detector and other gas detection equipment is different, using a SnO_2 as the main metal oxide semiconductor as a detection element, when the element is in contact with flammable or toxic gases , The resistance value of the element changes drastically, and by using this change, the gas concentration is converted into electricity to be measured. The instrument’s detection section uses a broad-spectrum element that responds to multiple gases. The measurement mechanism of the instrument is a bridge. The indication of the bridge has a certain relationship with the gas concentration. The instrument is also equipped with a limited number of internal alarm body, when the measured gas concentration exceeds a predetermined amount of the limit, the bridge output to promote the emitter coupling flip flip, connect sound, light alarm circuit with alarm sound and flash alarm. In order to probe components with a constant operating temperature, the machine is equipped with high-efficiency DC