The Bieler + Lang GMC 8420 Four Channel Controller

Our GMC-8420 is a four channel Gas Detection Controller that allows you to monitor a range of Toxic and/or Flammable gas detectors, Flame Detectors and Smoke/Heat Detectors, simply and easily. The GMC 8420 is a convenient wall-mounted control system that requires no additional internal wiring.

The unit has allowance for up to meauring channels (4-20mA), two alarm relays, one fault relay and one additonal audible alarm output. It also allows for testing the alarms without the nedd for calibration gas. To prevent false alarm when calibrating the connected sensor probes, the alarm trigger of the analysis unit can be suppressed using a special menu. Cutting short; the Bieler + Lang GMC-8420 Four Channel gas detection controller is a compact but powerful control system that combines simple operation with an extensive array of input and output functions.


  • Four Channel Gas Detection Controller
  • Two Alarm Thresholds
  • Two Alarm Relays, one Sounder Relay and one Fault Relay
  • Large Segment Display
  • Convenient Wall-mountable Control System
  • Alarm testing without need for test gas

Typical Applications

  • Measuring and Displaying Gas Concentrations
  • Monitoring and Dangerous Gas Signaling
  • Smaller Gas Detection Control Systems