... 20mA, 3 wire connection ,compatible with existing alarm control unit or DCS (Distributed Control System) 2) Flameproof body design acc ... backlight LCD display: measuring range,digital gas reading ,units, bar graph , system status etc.4) International standard plug-in ... 52 bars meter with 2% resolution10) Unit: ppm, mA, %,%LEL%VOL11) Operating temperature: -40~70C (According to gas sensor operating ...