Gastec GOMHC-3A Multiple Gas Detector for Oxygen, Flammable Gas, Carbon Monoxide, Hydrogen Sulphide

Description

The GOMHC-3A integrates four distinct sensing technologies into a single, compact chassis:

Oxygen: H-3A (Galvanic Cell)
Flammable Gas: FG-3A (Catalytic Combustion)
Carbon Monoxide: CO-603E (Electrolysis)
Hydrogen Sulphide: HS-602E (Electrolysis)

The device features an internal suction pump, allowing users to draw samples from up to 30 meters away using an extension hose. This ensures the atmosphere is tested before any worker enters a hazardous zone. Its large, backlit LCD displays all four gas concentrations in real-time, and its alarm system (90dB buzzer, flashing LEDs, and vibration) provides redundant alerts in dangerous conditions.

Brand

Gastec

Although, technology is always evolving, one demand on our products never changes: the demand for customer safety. Whenever we contribute to customer safety, we are presented with an opportunity to develop further.

GASTEC holds this corporate creed of safety and development in high esteem, as it strives to grow while always putting customer safety first.

Features

Quad-Gas Monitoring: Consolidates four essential sensors into one device, reducing the equipment load for safety personnel.
Active Suction Sampling: The built-in pump is powerful enough for deep-tank or manhole sampling via extension lines.
Intrinsically Safe: Certified for use in hazardous areas (Zone 0/1) where explosive vapors are a constant threat.
High-Resolution Toxic Sensing: Detects $CO$ and $H_2S$ in 1 ppm (or 0.1 ppm for $H_2S$ ) increments for precise exposure tracking.
Data Logging Capability: Stores historical gas data and alarm events for post-incident analysis and compliance reporting.

Specifications

Feature	Specification
Model Number	GOMHC-3A
Gases Detected	$O_2$ , $LEL$ , $CO$ , $H_2S$
Oxygen Range	0.0 – 25.0%
Flammable Range	0 – 100% LEL
$CO$ Range	0 – 300 ppm (Up to 999 ppm)
$H_2S$ Range	0.0 – 30.0 ppm (Up to 100 ppm)
Sampling Method	Internal Suction Pump
Weight	Approx. 450g

Applications

Comprehensive Pre-Entry Clearance: The GOMHC-3A is applied as the definitive safety check for multi-hazard environments.

Clean Air Start: Power the unit on in fresh air. It will perform a self-diagnostic on the pump and all four sensors.
One-Touch Calibration: Adjust the unit to its baseline ( $O_2$ at 20.9%, others at 0).
Remote Testing: Connect the extension hose and lower the probe into the workspace. Allow sufficient time (1 second/meter + sensor response) for the sample to reach the internal manifold.
Entry & Monitoring: If cleared, the worker clips the unit to their belt or harness for continuous “breathing zone” monitoring while inside.
Sensor Replacement: This unit contains four consumable parts that must be replaced when they can no longer be calibrated: