... )Unit:ppm, mA, %,%LEL,%VOL 4)Humidity:10-95%RH CO2 gas detector Technical features* 4-20mA, 3 wire connection ,compatible with ... , mA, %,%LEL,%VOL* Operating temperature: -40~70°C (According to gas sensor operating conditions)* Humidity: 10-95%RH (non condensing)* Ex-protection ...