We are offering fixed gas detector.high precision & durabilityreliable performance with its very low deviation tolerancesautomatic sensor error detectionset relay outputs for low/high alarm levelsled displaytemperature compensationautomatic zero calibration function4-20ma analog signal output in compliance with all 4-20ma control systemsrs485 compatibleremote calibration without opening its cover, via its infrared remote control deviceex-proof design for use in all combustible, flammable and/or explosive environments.