Gas detector DAHUA HY-GA40A — Methane sensor, wall-mounted, DC powered, 86.6×86.6×29.2 mm

Dahua Technology HY-GA40A gas detector Methane is a wall-mounted detector designed for continuous monitoring of methane (CH4). It uses a catalytic-type gas sensor and an MCU-based control system to provide stable long-term detection. The device includes a built-in high-volume buzzer and relay output for linkage with exhausting fans or automatic valve shutoff. The alarm threshold is set at 10% LEL and the detector can also monitor ambient temperature.

Advantages

The HY-GA40A offers precise methane measurement through a catalytic sensor that provides stable performance and sensitivity with low false alarms. It features rapid audible and visual alerts when the gas concentration reaches the alarm threshold, and supports intelligent linkage to external devices such as exhaust fans or pipeline valves to help remove or isolate combustible gas sources. Compact wall-mounted design and low power consumption make it suitable for continuous operation in small spaces.

Suitable for

• Residential kitchens and homes
• Restaurants and hotel kitchens
• Small commercial premises with natural gas or methane use
• Boiler rooms and utility closets where methane leaks are possible

When it may not be suitable

This detector is specifically calibrated for methane using a catalytic sensor with an alarm threshold at 10% LEL. It is not intended for detection of gases other than methane unless explicitly supported by the manufacturer. Environments with explosive atmospheres requiring intrinsically safe certified equipment, or locations needing detection at parts-per-million sensitivity for toxic gases, may require specialized detectors.

Key specifications

• Detected gas: Methane (CH4)
• Sensor type: Catalytic-type gas sensor
• Alarm threshold: 10% LEL
• Power source: DC
• Maximum power consumption: 0.8 W
• Mounting: Wall
• Detection distance (recommended): 1 m
• Dimensions (W×H×D): 86.6 × 86.6 × 29.2 mm
• Built-in alert: High-volume buzzer and visual indicator
• Outputs: Relay output for linkage to exhaust fan or valve control

How to use

Install the detector on a wall approximately 1 meter from the potential leak source and at a height appropriate for methane accumulation (methane is lighter than air and tends to gather near ceilings). Connect the device to the DC power supply and to external equipment (exhaust fan or valve actuator) via the relay output if automatic linkage is required. After powering on, allow the sensor to stabilise according to the manufacturer’s warm-up recommendation before relying on alarm outputs. When the buzzer and visual indicator activate at or above the 10% LEL threshold, follow local safety procedures to ventilate, isolate the gas source and evacuate if necessary.

What to consider before purchase

• Confirm methane is the target gas to detect; this detector is calibrated for CH4.
• Check installation location and height for optimal methane detection (methane rises).
• Verify power availability (DC) and compatibility with existing safety systems for relay linkage.
• Consider environments that require intrinsic safety certification if used in hazardous/explosive zones.
• Plan for periodic maintenance and sensor replacement intervals per manufacturer guidance.

Usage recommendations

Place the detector near probable leak points (gas appliances, pipeline connections) and test regularly. Keep the unit clean and free of obstructions, and ensure relay connections to fans or shut-off valves are tested during commissioning to confirm automatic response at the 10% LEL alarm point.