3M GD-6 User Manual

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The 3M™ Macurco™ GD-6 Combustible Gas Detector, Controller and Transducer is a low voltage device with selectable 4-20mA 

output, buzzer and digital display options. It is an electronic detection system used to measure the concentration of combustible 

gas and provide feedback and automatic exhaust fan control to help reduce combustible gas concentrations in parking garages, 

maintenance facilities or other light commercial applications. The 3M™ Macurco™ GD-6 Combustible Gas Detector is a low level 

meter capable of displaying from 0-50% LEL (Lower Explosive Limit) of combustible gas. The 3M™ Macurco™ GD-6 Combustible 

Gas Detector is factory calibrated and tested for proper operation, but can also be calibrated in the field.
List of Warnings and Cautions within these User Instructions

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• Each person using this equipment must read and understand the information in these User Instructions before use. Use 

of this equipment by untrained or unqualified persons, or use that is not in accordance with these User Instructions, may 

adversely affect product performance and 

• Use only for monitoring the gas which the sensor and instrument are designed to monitor. Failure to do so may result in

exposures to gases not detectable and 

cause sickness or death. For proper use, see supervisor or User Instructions, or 

call 3M in U.S.A., 1-800-243-4630. In Canada, call Technical Service at 1-800-267-4414.

• GD-6 may not function effectively below 0°F or above 125°F (-18°C or above 52°C). Using the detector outside of this

temperature range may adversely affect product performance and 

result in sickness or death.

• This detector helps monitor for the presence and concentration level of certain specified airborne gases. Misuse may

produce an inaccurate reading, which means that higher levels of the gas being monitored may be present and could 

result in overexposure and 

cause sickness or death. For proper use, see supervisor or User Instructions, or call 3M in 

U.S.A., 1-800-243-4630. In Canada, call Technical Service at 1-800-267-4414.

• Each time the unit is turned on it performs a self-test, which activates visual alarms. If the self-test fails, or if all the alarms do

not activate, do not use. Failure to do so may adversely affect product performance and 

result in sickness or death.

• Do not cover or obstruct visual alarm. Doing so may adversely affect product performance and

result in sickness or death.

• Do not disassemble unit or attempt to repair or modify any component of this instrument. This instrument contains no user

serviceable parts, and substitution of components may impair product performance and 

• Using a certified gas with a concentration other than the one listed for this instrument and sensor when conducting a

calibration or calibration verification test (bump test) will produce inaccurate readings. This means that higher levels of the 

gas being monitored may be present and could result in overexposure and 

cause sickness or death. For proper use, see 

supervisor, User Instructions or call 3M in U.S.A., 1-800-243-4630. In Canada, call Technical Service at 1-800-267-4414.

• The following steps must be performed when conducting a calibration or calibration verification test (bump test) to ensure proper

performance of the monitor. Failure to do so may adversely affect product performance and 

result in sickness or death.

•  When performing a calibration or calibration verification test (bump test) only use certified calibration gas at the

required concentration level. Do not calibrate with expired calibration gas.

 •  If the instrument cannot be calibrated, do not use until the reason can be determined and corrected.
 •  Do not cover or obstruct display or visual alarm cover.
 •  Ensure sensor inlet is unobstructed and is free of debris.

Each person using this equipment must read and understand the information in these User Instructions before use. Use 

of this equipment by untrained or unqualified persons, or use that is not in accordance with these User Instructions, may 

adversely affect product performance and 

The 3M™ Macurco™ GD-6 Combustible Gas Detector helps combustible gas detection and automatic exhaust fan control 

for automotive maintenance facilities, enclosed parking garages, warehouses with forklifts, etc. The 3M™ Macurco™ GD-6 

Combustible Gas Detector can be used with 12VDC or 24VDC N.O. (fire/security) panels.

Use only for monitoring the gas which the sensor and instrument are designed to monitor. Failure to do so may result in 

exposures to gases not detectable and 

cause sickness or death. For proper use, see supervisor or User Instructions, or 

call 3M in U.S.A., 1-800-243-4630. In Canada, call Technical Service at 1-800-267-4414.

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Do not Use For
The 3M™ Macurco™ GD-6 Combustible Gas Detector is 

noT intended for use in hazardous locations or industrial applications 

such as refineries, chemical plants, etc.  

Do noT mount the 3M™ Macurco™ GD-6 Combustible Gas Detector where the normal ambient temperature is below 0°F or

exceeds 125°F (-18°C or above 52°C). The 3M™ Macurco™ GD-6 Combustible Gas Detector mounts on a type 4S electrical

box supplied by the contractor. 

The 3M™ Macurco™ GD-6 Combustible Gas Detector may not function effectively below 0°F or above 125°F (-18°C or

above 52°C). Using the detector outside of this temperature range may adversely affect product performance and

General Description 
The 3M™ Macurco™ GD-6 Combustible Gas Detector is a low voltage, dual relay combustible gas (EX) detector and automatic 

ventilation controller. The 3M™ Macurco™ GD-6 Combustible Gas Detector uses a microcomputer controlled, electronic 

system to measure the concentration of combustible gas, actuate relays and provide a 4-20mA (0-50% LEL) output. The  

3M™ Macurco™ GD-6 Combustible Gas Detector is low maintenance with a long life (5+ years) pellistor sensor and optional 

gas test and calibration kits. The 3M™ Macurco™ GD-6 Combustible Gas Detector is a low level meter capable of displaying 

from 0-50% LEL of combustible gas.