Basic Knowledge on Gases
Combustible gas detection is critical for preventing fires and explosions in industrial settings. When gases like hydrogen, methane, or propane accumulate and reach explosive limits, even a minor spark can trigger a catastrophic event. At PureAire Monitoring Systems, we specialize in real-time detection technologies that identify dangerous gas levels well before they pose a threat—ensuring continuous safety and compliance.
What Is a Combustible Gas?
A combustible gas is any gas that can ignite and burn when mixed with air and exposed to a source of ignition. Common examples include:
- Hydrogen (H₂)
- Methane (CH₄)
- Propane (C₃H₈)
- Isobutane (C₄H₁₀)
- Ethanol and Methanol
These gases are essential to industrial processes, but require strict monitoring to avoid combustion risks.
Understanding Explosion Limits (LEL & UEL)
Explosion limits refer to the range of gas concentrations in air that can ignite:
- LEL (Lower Explosive Limit): The lowest concentration at which a gas can combust.
- UEL (Upper Explosive Limit): The highest concentration at which a gas can still ignite.
Here are some common explosion limits:
| Gas | LEL (%vol) | UEL (%vol) |
|---|---|---|
| Hydrogen | 4.0 | 75.6 |
| Methane | 5.0 | 15.0 |
| Propane | 2.1 | 9.5 |
| Iso-butane | 1.8 | 8.4 |
| Toluene | 1.2 | 7.0 |
| Methanol | 5.5 | 44.0 |
| Ethanol | 3.5 | 19.0 |
PureAire’s combustible gas detection diagram visualizing the explosive range between the Lower and Upper Explosion Limits (LEL and UEL), with alarm set below 25% LEL.
PureAire’s Combustible Gas Detection Technology
PureAire offers industry-leading gas detection systems engineered to keep environments safe from combustible gas hazards. We now proudly offer the new MPS™ Flammable Gas Monitor, a revolutionary sensor that detects up to 15 flammable gases with no calibration required.
Now Featuring: The MPS™ Flammable Gas Monitor
Unlike traditional catalytic bead or MOS sensors, the MPS (Molecular Property Spectrometer™) delivers accurate, real-time gas classification without cross-interference or drift. It requires no calibration over its lifetime, cutting downtime and maintenance costs.
- ✔️ Detects Hydrogen, Methane, Propane, Ethanol, Butane, Ammonia, Acetylene, and more
- ✔️ No false alarms from humidity, temperature, or interfering gases
- ✔️ Lifetime factory calibration – no recalibration needed
- ✔️ Certified to UL 2075 and ATEX/IECEx standards
- ✔️ Modbus or 4-20 mA output for PLC/SCADA integration
View Full Specs of the MPS Flammable Gas Monitor →
Sensor Options Tailored to Your Application
Depending on your environment and gas type, we also offer:
- Metal Oxide Semiconductor Sensors (MOS): Ideal for general hydrocarbon detection.
- Catalytic Bead Sensors: Time-tested for combustible gas monitoring.
- Electrochemical Sensors: Accurate for toxic flammable gases like ammonia.
Our solutions ensure compliance with LEL safety thresholds and integrate seamlessly with emergency systems, alarms, and facility controls.
Applications Across Industries
- Hydrogen Production: High-range explosion limits require fast-response detection.
- Chemical Labs: Real-time propane and methane monitoring during experiments.
- Industrial Plants: Combustible leak detection in confined spaces.
Why Choose the MPS Flammable Gas Monitor from PureAire?
- ✔️ Measures 14+ Gases and Gas Mixtures
- ✔️ Engineered to exceed EN50194 and UL1484 standards
- ✔️ Low-maintenance, long-life sensors (up to 15 years)
- ✔️ Full integration with SCADA, PLCs, and IoT monitoring platforms
For over 25 years, institutions and facilities across science, technology, manufacturing, and healthcare worldwide have trusted PureAire’s industry-leading gas detection systems in the most demanding applications.
Get Started with Safer Combustible Gas Detection
Contact our experts today for a consultation or request a custom quote on our MPS Flammable Gas Monitor.
