Why You Need a Fixed Methane (CH4) Detector — Continuous Monitoring for Biogas, Landfill Gas, and Natural Gas Facilities
Methane (CH4) is continuously generated in sewage-treatment digesters, food-waste biogas facilities, landfills, natural gas pipelines, coal mines, and more. Because it is colorless, odorless, and tasteless, human senses cannot detect a leak at all. Leaks continue even at night, on holidays, and other times when no workers are present, so 24-hour continuous monitoring with a fixed gas detector is the key to accident prevention. The WANDI FIX800 simultaneously detects up to 5 gases including CH4, and auto-links with DCS/SCADA when an alarm is triggered.
💡 The Key Role of a Fixed CH4 Detector
It detects explosion risk early even when no workers are present, and sends an instant alert to the central control room, enabling an early response.
Methane (CH4) Explosion Risk — Effects by Concentration
| Concentration | Risk Type | Effect | Risk Level |
|---|---|---|---|
| 1,000 ppm (0.1%) | 10% LEL | Stage-1 alarm threshold | 🟡 Caution |
| 2,500 ppm (0.25%) | 25% LEL | Stage-2 alarm, evacuate immediately | 🔴 Danger |
| 50,000 ppm (5%) | 100% LEL (lower explosive limit) | Explosion occurs upon ignition | ☠️ Explosion |
| 150,000 ppm (15%) | UEL (upper explosive limit) | Asphyxiation risk zone | ☠️ Asphyxiation |
| When accompanied by oxygen deficiency | Lowered O2 concentration | Loss of consciousness, death | ☠️ Fatal |
※ Per Korea Gas Safety Corporation (KGS) standard, CH4 lower explosive limit (LEL): 5 vol%
Real Incident Cases — Accidents Caused by the Absence of a Fixed CH4 Detector
Case 1: Methane Accumulation Explosion in a Natural Gas Pipeline Valve Room (2019, Incheon)
At a natural gas supply facility valve room in Incheon, gas leaked continuously from a pipe joint, but with no fixed detector the leak went unnoticed; ignition occurred during electrical inspection work, leading to an explosion that left one worker with severe burns and damaged part of the facility. (Source: Korea Gas Safety Corporation gas accident yearbook, 2019)
Case 2: Methane Leak Fire Around a Sewage Treatment Plant Digester (2021, Gyeonggi)
At a sewage treatment plant in Gyeonggi Province, methane gas leaked continuously through a crack in the digester's outer wall, and an electrical spark near the digester caused a fire. The investigation concluded that had a fixed CH4 detector been installed around the digester, an alarm could have been raised at the early stage of the leak. (Source: Korea MoEL industrial accident cause analysis report, 2021)
A Scenario for Preventing CH4 Explosion Accidents with WANDI FIX800
FIX800 — Fixed Industrial Gas Detector with 5-Gas Simultaneous Detection
The WANDI FIX800 is a fixed gas detector that simultaneously detects up to 5 gases including CH4 — plus EX (combustible gas), H2S, CO, and O2. With 24-hour continuous monitoring it instantly detects night and holiday leaks, and integrates perfectly with DCS/SCADA via 4~20mA analog output and relay contacts.
simultaneous detection
including nights and holidays
automatic interlock
If FIX800 Had Been Installed — Accident Prevention Scenario
- 1Early leak detection: Install FIX800 near pipe joints and valve rooms. A stage-1 alarm fires the instant CH4 reaches 10% LEL.
- 2Automatic shutoff interlock: When 25% LEL is exceeded, the emergency shutoff valve (SOV) operates automatically. Cutting the gas supply prevents an explosion.
- 3Instant control-room alert: Real-time CH4 concentration sent to the DCS via a 4~20mA signal. Remote control-room monitoring is possible even at night.
- 4Automatic ventilation/fire-system interlock: Linking the alarm signal with exhaust fans and the fire system enables forced ventilation and fire-readiness at the early stage of a leak.
Real Installation Case — Biomass Facility CH4+H2S Fixed Monitoring (Daegu)
Confined-Space Methane/Hydrogen Sulfide Fixed Detection Site (Pohang)
FIX800 Product Specifications (CH4/EX Detection)
| Item | Specification |
|---|---|
| Model name | FIX800 |
| Detection type | Fixed (stationary) type |
| Detected gases | EX (including CH4), H2S, CO, O2, VOC — up to 5 gases simultaneously |
| EX measurement range | 0~100% LEL |
| Output signal | 4~20mA analog / relay contact output |
| Alarm settings | Stage 1 (10% LEL) · Stage 2 (25% LEL) independently configurable |
| Power | DC 24V |
| Dust/water protection | IP65 or higher |
A Closer Look at the WANDI FIX800
Below are real photos of the WANDI FIX800 fixed multi-gas detector.
