... , greatly satisfy the industrial site safety monitoring of equipment with high reliability requirements, widely used in petroleum, chemical, ... ppm,%VOL,%LEL,mg/m3 Acousto-optic alarm means:, vibration Working temperature: - 40 ~ 70 °C Work humidity: 0 ~ 95% RH not ... and buzzer, indicator. All alarm 1 times says the normal starting, if electricity shortage or detection. Less than sensor has long ...