Description E4000 is a portable model with multiple gas detectors. It can continuously measure the concentrations of up to four combustible gases, oxygen, and toxic gases in the surrounding environment, and issue an alarm when the gas levels are abnormal.By adopting interchangeable smart sensor module, it can be made for detecting 2 gases, 3 gases and 4 gases. It is applicable to explosion-proof places: steelworks, petrochemical plant, oil industry, shipbuilding yard, sewage treatment plant, mine, power supply works etc. Key Features Smart interchangeable sensor module MOS, catalytic, electrochemical, infrared, PID sensors selectable Two alarm level STEL alarm and TWA alarm for toxic gases Visual, audible, vibrating alarm Self protection against high concentration combustible gas Low battery alert Data uploading Password management Self-test when power on Self-diagnostic and self-correction function GPS, GPRS and Man-down function optional Built-in sampling pump (optional) Adjustable alarm levels and span calibration value Calibration point adjustable