Data recovery function: Selective recovery or full recovery. Built-in pump suction measurement, fast response, sampling distance of more than 10 meters. Automatic zero-point tracking and multi-level calibration of target point improve the linearity and accuracy of measurement. Waterproof, dustproof, explosion-proof, shockproof, intrinsically safe circuit design, antistatic, anti-electromagnetic interference. The three display modes can be switched, and you can set whether to display the maximum value, minimum value, and gas name, and you can view the historical record graph.