They are factory calibrated to a particular gas or vapor. They withstand rugged and dirty environments and use electrocatalytic bead-sensing technology. They feature digital LEDs along with LED indicators of alarm, fault, and status. They operate on 117-Vac, 50 to 60-Hz (optional 220-Vac, 50 to 60-Hz) or 24-Vdc input power with 24-Vdc battery backup capability. The controllers can be wall, panel or rack mounted in nonhazardous areas. Both units are CSA approved.

General Monitors,p 26776 Simpatica Circle, Lake Forest, CA 92630, (800) 330-9161, generalmonitors.com