Bieler+Lang GMC 8022 — 2-channel gas controller

A controller for two gas sensors with a 4–20 mA output, mounted on a DIN rail in an ordinary distribution board. It displays the concentration, raises the alarm and triggers the protective measures — ventilation, shut-off valve, horn, warning light.

What it does

The GMC 8022 is the acting part of a gas detection system: the sensors measure, the controller decides. It reads the 4–20 mA signal from up to two detectors, shows the current concentration and switches its relays when a level is exceeded.

Those relays drive what actually has to happen: a fan to extract the gas, a solenoid valve to cut the supply, a horn and an illuminated sign. Alarm 1 usually starts the ventilation, alarm 2 triggers shut-off and evacuation.

Why two channels are enough more often than you would think

A boiler room, a laboratory, a cylinder store, an LPG station, a small paint shop — in all of these two measuring points cover the whole risk. An 8-channel controller would be money spent for nothing, and the 8022 fits into the distribution board next to the protection gear without needing a cabinet of its own.

Where there are more points, the same family offers the 4-channel GMC 8034 — three alarm levels and a colour-changing display.

SIL 1 and the measurement function certificate

The unit is suitable for functional safety to SIL 1 and carries a measurement function certificate BVS 03 ATEX G007 X. That is not the same as a plain declaration of conformity: the measuring function has been verified by a notified body, which is often required when an installation is signed off by an assessor or an insurer.

The controller is installed outside the hazardous area; only the sensors sit in zone 1. The alarm output can be checked without test gas, which shortens the periodic inspection.

What it works with

Any Bieler+Lang detector with a 4–20 mA output: ExDetector HC 100 and HC 200 for flammable gases, SC 220 where pellistors get poisoned, ExMonitor and GasMonitor for toxic gases and oxygen, GasDetector IR 220 for refrigerants.

Technical data

Parameter	Value
Type	gas measuring computer (controller) for top-hat rail mounting
Channels	2
Measuring inputs	2 × 4–20 mA signal
Functional safety	SIL 1
Measurement function certificate	BVS 03 ATEX G007 X
Alarm levels	Alarm 1 and Alarm 2 — collective outputs for channels 1 and 2
Relay outputs	Alarm 1, Alarm 2, horn, fault — floating contacts
Contact rating	230 VAC / 2 A · 30 VDC / 2 A
Supply voltage	230 VAC 50–60 Hz or 24 VDC (21.7–28 VDC, SELV)
Indication	LEDs per channel (alarm 1, 2, fault, displayed sensor), ready, horn, digital concentration display
Controls	3 buttons — horn and alarm reset, menu, programming
Fault monitoring	mains failure, computer fault, wire breakage or short circuit of the sensor lines
Ex zone	sensors in zone 1; the controller itself outside the hazardous area
Manufactured in	Germany

Service with us

We are an authorised Bieler+Lang trade and service partner — we hold the manufacturer's written authorisation covering commissioning, maintenance and other service work, valid until 31 December 2028. Our technicians were trained in Achern and work with original parts and factory procedures.

In practice that means we commission, calibrate and service what we sell — nothing has to be shipped back to Germany. See our service scope or send equipment in.