... 93%RHrange of sound pressure >75dB/mpreparation electricity working time >2 hoursconcentration of alarm 25%LEL 50%LELconcentration of ... of functions: real-time check of data,fault detecting,power management,alarm display,alarm indication ,relay outputs etc ,1 ... unit detectors,Intelligent system:easy zero calibration,free relay output,4 passive relay contact output ,linkage programmer ,easy to install ...