Liquid crystal dot matrix display technology, which can display gas type, gas unit, gas concentration value, measurement Max value, local time, etc. With self-calibration function and zero calibration function, the gas monitoring is accurate and reliable One-key factory reset function, can avoid the trouble of misoperation With temperature and pressure compensation, it can realize the compensation of gas concentration under different temperature and pressure environments Two-level sound and light alarm, the alarm point can be set by yourself