Key features: 1.Catalytic bead based pellistor sensor cell with low flash energy 2. 10-bit microprocessor control unit 3.Non-intrusive one man calibration via hall effect switches 4.Atex certified explosion proof / flameproof, suitable for zone 1, 2 gas explosion installation 5.Linear, proportional analog industry standard current output 6.Continuous system self-diagnosis with watch dog 7.Flashback arrestor with sintered filter 8.Auto zero point tracking to zero point compensation 9.Sil 2 hw tuv certified 10.Rs485 serial interface with modbus rtu communication (optional) 11. 1 or 3 relay output module (optional) 12.System and alarm led indicators (optional) 13.Modbus rtu communication over rs485 serial interface Technical specifications: Measuring parameters: hydrogen gas flammability or leakage Sensor technology: catalytic bead based pellistor sensor cell Measuring range: 0 ~ 100 % lel ( 0 ~ 4% v/v @ stp) Response time (t90): < 30 sec Control unit: 10 bit microprocessor based Warm up time: < 5 mins Auto zero point tracking for drift compensation Power supply: 24 vdc Ingress protection: ip65 Enclosure: stainless steel (for sensor cell), anti-static epoxy coated metal alloy (for transmitter) Output: linear, proportional 4-20ma Mounting: wall, duct, pipeline Safety integrity level: sil 2 Atex marking: ce 722 ex ii 2g eex d iic t6, ce 722 ex ii 3g eex na iic t6 Optional: lcd display, alarm leds, potential free relay contacts Hazardous area: zone 1, 2 Application: 1.Oil & gas, petrochemical, refinery 2.Battery rooms, ups facility 3.Mobile switching center (msc) of cellular / telecom site 4.Cracking plants 5.Hydrogenation plants 6.Chemicals 7.Cold stores 8.Pharmaceuticals, medicinal formulation