The Bacharach Model HGM-SZ Single Zone (tube) Refrigerant Gas Monitor is designed for continuous monitoring of CFC, HFC, and HCFC refrigerants and halogen gases with a 1/4 in. O.D. tube up to 50 ft (15m) distance from measuring point to monitor. The unit features 30 pre-programmed refrigerants plus one custom gas. Three adjustable alarm levels with relay output designate leak, spill, and evacuation concentrations. Gas alarms and system fault conditions are indicated by visual and audible alarms. The Model HGM-SZ provides a system fault relay output and a 4 to 20 mA output for integration with remote monitoring equipment or building management systems.The HGM-SZ Single Zone (tube) Refrigerant Gas Monitor is designed to be used as part of a control system that helps to prevent the formation of a hazardous environment when properly installed and maintained. For more information on the proper application and use of this product please read 'Environmental Safety Devices' in our technical reference section.