... Concentration unit:ppm,%VOL,%LEL,mg/m3 Acousto-optic alarm means:, vibration Working temperature: - 40 ~ 70 °C Work humidity: 0 ~ 95% RH ... measurement interface, Lower gas species, right now display vibration motor and buzzer, indicator. All alarm 1 times says the normal starting, if ... . If the instrument is pump suction method, the screen Will display pump icon, and has been in rotation, and if no ...