... warning predetermined value, the controller may send out the acousto-optic warning, and sends out the control signal, prompts the ... /mpreparation electricity working time >2 hoursconcentration of alarm 25%LEL 50%LELconcentration of alarm error < ±3%LELalarm method sound and ... real-time check of data,fault detecting,power management,alarm display,alarm indication ,relay outputs etc ,1 signal for RS- ...