1:for lpg, co, h2s gas etc 2:catalytic,electrochemical, pid ... 's a lpg gas detector, Gas Analyzer, Alarm with HBUS signal transmission.It can network with our gas monitor JB ... gas, VOC (Certain Organic Vapors)Working voltageDC14V~35V( detector terminal)Signal transmit 4~20mA Dimension 160mm×68mm×185mm Weight ... ); pressure range:86~106kPa Cheaper combustible gas detector with real-time display