Product Categories

Fixed Combustible Gas Detector
Indoor Natural Gas & LPG Leak Detection with Relay or Solenoid Valve Signal Output
Type: AS-705L / AS-705D
Related: Alarm Detector
The AS-705 is a fixed indoor combustible gas detector for natural gas and LPG leakage detection, supplied in two power-configuration models — AS-705L (DC 9–24V) and AS-705D (AC 220V) — with a choice of relay output or solenoid valve signal output for integration with gas-safety systems.
This page is intended for importers, distributors, wholesalers, and system integrators evaluating the AS-705 for sourcing, distribution, or project integration.
Quick reference for procurement evaluation:
| Question | Answer |
| What gases? | Natural gas, LPG |
| What power versions? | AS-705L: DC 9–24V / AS-705D: AC 220V |
| What output types? | Relay (SPDT/1C) or solenoid valve signal (not simultaneous) |
| Installation type | Fixed, indoor, ceiling or wall-mounted per gas density |
| Standard documented | GB15322.2-2003 |
1. AS-705 Overview
The AS-705 detects combustible gas leakage — specifically natural gas and liquefied petroleum gas (LPG) — using a high-stability semiconductor gas sensor and microprocessor-based control. When gas concentration reaches the detector’s alarm threshold, the unit activates a red LED alarm indication and an audible alarm, and — depending on the ordered output configuration — outputs a relay signal or a solenoid valve control signal to external gas-safety equipment.
The AS-705 also provides automatic sensor-fault indication (yellow LED), a manual self-test button, and automatic alarm reset once gas concentration falls below the alarm threshold.
This detector is designed for indoor fixed installation only and is not a portable instrument.
2. Key Product Characteristics
- Natural gas and LPG detection
- High-stability semiconductor gas sensor, low sensitivity drift
- Two power-supply models: DC 9–24V / AC 220V
- Relay output or solenoid valve signal output
- Audible and visual (LED) alarm
- Automatic sensor-fault indication
- Manual self-test function
- Automatic alarm reset
- Manufactured using SMT process
- Ceiling mounting; base compatible with 86-type junction boxes
3. Natural Gas and LPG Detection
The AS-705 is documented to detect:
- Natural gas
- Liquefied petroleum gas (LPG)
The detector is not designed to detect carbon monoxide or other toxic gases. Buyers sourcing for CO or toxic-gas detection applications should not specify this model.
Because natural gas is lighter than air and LPG is heavier than air, installation position differs by gas type.
4. Power-Supply Options
| Model | Power Supply | Typical Use Case |
| AS-705L | DC 9–24V | Integration with DC-powered alarm/control systems |
| AS-705D | AC 220V | Direct connection to AC mains-powered installations |
Buyers and integrators should confirm the required model at the time of inquiry, as the two models are not interchangeable without matching system power supply.
5. Relay and Solenoid Valve Output Options
This is a key purchasing parameter and should be confirmed before ordering.
5.1 Relay Output Configuration
- Common contact
- Normally closed contact
- Normally open contact
- Relay type: 1C / SPDT
- Contact load: 3A 250VAC / 30VDC
Suitable where the detector needs to provide a dry-contact switching interface to external panels or equipment.
5.2 Solenoid Valve Signal Output Configuration
- Positive signal output
- Negative signal output
Suitable where the detector needs to directly drive a gas solenoid valve to shut off gas supply on alarm.
5.3 Configuration Limitation
The relay output and solenoid valve output cannot operate simultaneously on the same unit. The required output type must be specified when ordering, and can be confirmed by checking the label on the rear of the unit prior to wiring.
6. Applications
The AS-705 is applicable to:
- Indoor gas-safety installations requiring natural gas or LPG leak detection
- Commercial and residential gas-safety projects (indoor only)
- Gas-safety systems requiring relay-based alarm signal integration
- Gas-safety systems requiring solenoid valve shutoff integration
Actual suitability for a specific project depends on target gas, installation environment, required power configuration, required output type, and applicable local regulations. Buyers should confirm project-specific requirements with Athenalarm before procurement.
7. Installation Considerations
Correct positioning is determined by gas density relative to air.
7.1 LPG (heavier than air)
- Install 0.3–1.0 m above the ground
- Install within a 1.5 m radius of the gas source
7.2 Natural Gas (lighter than air)
- Install 0.3–1.0 m below the ceiling
- Install within a 1.5 m radius of the gas source
7.3 Locations to Avoid
- Too close to a gas stove
- Beside exhaust fans
- Near doors or windows
- In locations with substantial water vapor (e.g., directly in bathrooms)
All wiring must comply with the product manual and applicable local electrical safety regulations. Improper wiring may prevent the unit from alarming correctly during an actual gas leak.
Note: This guidance reflects the installation instructions and is not a substitute for applicable local building/safety codes, which buyers and installers should independently confirm for their target market.
8. Technical Specifications
| Parameter | AS-705L | AS-705D |
| Power Supply | DC 9–24V | AC 220V |
| Current Consumption | Documented as Static ≤110µA / Alarm ≤160µA | Same |
| Sensor | High-stability semiconductor gas sensor | Same |
| Detection Gas | Natural gas, LPG | Same |
| Alarm Concentration | 6% | Same |
| Stability | ±3% LEL | Same |
| Alarm Output | Audible and visual alarm; relay or solenoid valve signal (per ordered configuration) | Same |
| Relay Type | 1C / SPDT | Same |
| Relay Contact Load | 3A 250VAC / 30VDC | Same |
| Alarm Sound Pressure | 75 dB at 1 m | Same |
| Operating Temperature | -10°C to +50°C | Same |
| Ambient Humidity | 5%–95% RH | Same |
| Storage Temperature | -25°C to +50°C | Same |
| Product Dimensions | Φ120 × 40 mm | Same |
| Power Indicator | Green LED, continuously on | Same |
| Alarm Indicator | Red LED, flashing | Same |
| Sensor Fault Indicator | Yellow LED, continuously on | Same |
| Mounting | Ceiling mounting, base compatible with 86-type box | Same |
| Manufacturing Process | SMT | Same |
| Documented Standard | GB15322.2-2003 | Same |
9. Operating Status and Alarm Functions
9.1 Startup / Warm-Up
On power-up, the green power LED illuminates continuously and the unit enters a warm-up period of approximately 3 minutes, during which the red and yellow LEDs alternately flash and the buzzer sounds briefly. Gas testing must not be performed during warm-up.
9.2 Normal Alarm Operation
When gas concentration reaches the alarm threshold: red LED flashes, buzzer sounds, and the configured relay/solenoid valve output activates.
9.3 Fault Indication
If the internal sensor fails, the yellow LED illuminates continuously with an audible fault tone. The unit should be powered off and the dealer contacted for service — the unit should not be opened by the end user.
9.4 Self-Test
A self-test button allows manual verification that the LED indicators and buzzer are functioning, without requiring an actual gas source.
9.5 Automatic Reset
The alarm condition automatically clears once gas concentration falls below the alarm threshold — no manual reset is required.
10. Maintenance and Sensor Lifecycle
- Cleaning: Remove dust from the unit surface with a vacuum cleaner once per month. Do not use detergents or solvents.
- Calibration: Annual calibration is recommended to maintain detection sensitivity.
- Sensor service life: The semiconductor sensor can be used for 5 years and we recommends replacement after the unit has been in service for more than 5 years.
- Failure handling: A failed sensor should be repaired or replaced promptly through the dealer/supplier.
11. Product Limitations
- This is a combustible gas detector only. It cannot be used to detect carbon monoxide or other toxic gases.
- The unit requires correct wiring and a stable, correctly rated power supply; abnormal power conditions will prevent normal alarm operation.
- The product can reduce the occurrence of accidents, but cannot ensure safety completely — we recommend this device be used alongside, not instead of, general household/facility gas-safety practices.
Buyers evaluating this product for toxic-gas or CO detection applications should not specify the AS-705.
12. OEM / Private Label
| Item | Status |
| OEM / private-label service | Available, subject to confirmed scope per order |
| Custom logo | Available — standard custom-logo MOQ: 200 pcs |
| Packaging customization | Available, at buyer’s cost |
| Housing customization | Available, at buyer’s cost |
| Model-number customization | Available, at buyer’s cost |
| Documentation/manual customization | Available, at buyer’s cost |
| Firmware / frequency customization | Not applicable to this product |
Buyers requesting OEM/private-label supply should provide target quantity, logo/branding requirements, and packaging preferences at inquiry stage so Athenalarm can confirm feasibility and terms in writing.
13. Quality and Manufacturing Evidence
- Manufactured using SMT (Surface-Mount Technology) process
- High-stability semiconductor gas sensor with documented low sensitivity drift
| Item | Status |
| Quality management certification | ISO 9001 |
| Incoming material inspection process | Sampling Inspection |
| In-process production inspection | Sampling Inspection |
| Finished-product testing procedure | 100% Production Testing |
| Third-party test report | Yes |
| Production capacity | 5000 pieces per month |
14. Certifications & Compliance
The AS-705 meets GB15322.2-2003.
| Compliance Item | Status |
| Current applicable Chinese standard/version | GB15322.2-2003 |
| Current product test report | China Quality Supervision Test Report |
15. Procurement Information
| Procurement Item | Information |
| Product | AS-705 Fixed Combustible Gas Detector |
| Models | AS-705L (DC 9–24V) / AS-705D (AC 220V) |
| Detection Gas | Natural gas / LPG |
| Output Options | Relay (SPDT/1C) or solenoid valve signal (specify one) |
| Standard MOQ | 10 pcs |
| Custom-Logo MOQ | 200 pcs |
| Other Customization | Contact Athenalarm to confirm |
| Standard Lead Time | 10 days |
| Custom-Logo Lead Time | 15 days |
| Sample Availability | Yes |
| Warranty | 1 year |
| OEM / Private Label | Yes, subject to confirmed scope (see OEM section) |
| Packaging | Paper box packaging |
| Technical Support | Available |
| Pricing | Quotation-based; depends on model, quantity, output configuration, OEM requirements |
To receive an accurate quotation, please specify: model (AS-705L/AS-705D), required output type, quantity, and any OEM/private-label requirements.
16. Frequently Asked Questions
Q1: What gases can the AS-705 detect?
Natural gas and liquefied petroleum gas (LPG).
Q2: What is the difference between AS-705L and AS-705D?
AS-705L is the DC version (9–24V). AS-705D is the AC version (220V). Confirm the correct model based on your system’s power supply.
Q3: Does the AS-705 support relay output and solenoid valve output at the same time?
No. Only one output type can operate on a given unit. Specify the required output type when ordering.
Q4: Can the AS-705 detect carbon monoxide?
No. This is a combustible gas detector only and is not designed for carbon monoxide or other toxic gases.
Q5: Does the detector reset automatically after an alarm?
Yes, once gas concentration falls below the alarm threshold, per the supplied documentation.
Q6: What is the sensor’s service life?
The semiconductor sensor can be used for 5 years and we recommend replacement after 5 years of service.
Q7: What is the MOQ and lead time?
Standard MOQ is 10 pcs with a 10-day lead time. Custom-logo orders require a 200 pcs MOQ with a 15-day lead time.
Q8: Is OEM/private-label service available?
Yes, subject to confirmed scope. Contact Athenalarm with your logo, packaging, and quantity requirements.
Q9: What certifications does the AS-705 have?
Test report.
Q10: What technical support is available?
Technical support is available; specific scope (pre-sales, wiring/integration support, after-sales) will be confirmed based on your inquiry.
17. Request a Quotation
If you are sourcing fixed combustible gas detectors for distribution, wholesale supply, OEM production, or system integration, contact Athenalarm with your requirements.
Please provide:
- Required model: AS-705L or AS-705D
- Required quantity
- OEM/private-label requirements, if applicable
Athenalarm will confirm applicable product configuration, commercial terms, documentation, and supply details in writing.
18. Download Product Documentation
Access complete technical documents and guides for the Athenalarm AS-705L 705D Fixed Combustible Gas Detector User Manual.



