Gastec GOA-7H Oxygen detector

Description

The GOA-7H utilizes a high-performance Galvanic Cell sensor (Model O2-204G). This electrochemical sensor acts like a small fuel cell, consuming oxygen to produce a voltage. It is optimized for “Diffusion” sampling, meaning it monitors the air that naturally circulates around the wearer’s breathing zone.

This model is “Industry 4.0 ready” in terms of reliability, featuring automatic sensor and circuit self-checks upon startup. While compact, it is ruggedized with an IP64 rating, making it suitable for use in dusty or damp conditions like tunnels, silos, and ship hulls.

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

Extreme Portability: At just 48mm wide and 110g, it is one of the least intrusive personal oxygen monitors on the market.
One-Touch “AIR” Adjustment: Allows the user to calibrate the sensor to the standard 20.9% oxygen level in fresh air with a single button press.
Triple-Threat Alarm: Ensures the user is notified even in high-noise or low-visibility areas via a 95 dB buzzer, flashing red LEDs, and a strong vibration motor.
Intrinsically Safe (Ex): Certified Ex ia IIC T3 Ga, allowing for safe operation in explosive gas atmospheres (Zone 0/1/2).
High Efficiency: Uses a single Panasonic LR03 (AAA) battery to provide nearly 6 months of continuous 24/7 operation (provided no alarms are triggered).
Interchangeable Design: The sensor can be detached from the main body and connected to optional extension cables (5m to 30m) for remote sampling.

Specifications

Feature	Specification
Measurement Range	0.0 – 25.0% (Service range up to 42.0%)
Measurement Principle	Galvanic Cell (Sensor O2-204G)
Resolution	0.1%
Alarm Threshold	< 18.0% (Deficiency) / > 23.5% (Enrichment – User settable)
Response Time ( $T_{90}$ )	Within 15 seconds (at 20°C)
Ingress Protection	IP64 (Dust-proof and splash-resistant)
Weight	Approx. 110g

Applications

Confined Space Monitoring: Worn by workers entering manholes, storage tanks, or underground vaults.
Marine & Shipping: Essential for personnel entering ship holds or ballast tanks where oxygen may be displaced by cargo or corrosion.
Agriculture: Protection against anoxia in grain silos, manure pits, or fermentation areas.
Cryogenic Safety: Worn by lab technicians or hospital staff working near liquid nitrogen or CO2 tanks that could leak and displace oxygen.
Civil Engineering: Safety in deep trenches or tunneling projects where heavy gases may settle.