The hazardous nature of gases does not depend on their smell or visibility: any gas can potentially threaten the safety of people, assets, and the environment. In industrial settings, safety relies on reliable systems capable of detecting gas hazards
before they become critical. This is the role of a gas sensor: a key component used to measure the presence and concentration of gases, forming the foundation of any gas detection system.
In this article, we explain how a gas sensor works, the main sensor technologies available, and their industrial applications, with examples from Teledyne Gas & Flame Detection solutions.
What Is a Gas Sensor and How Does It Work?
A gas sensor is the core element inside a gas detection device. Its purpose is to identify the presence and concentration of a specific gas in the ambient air and convert that interaction into an electrical signal.
A gas sensor is typically made up of:
1. The sensing element
This is the central component that reacts chemically or physically when exposed to a target gas. The reaction generates a measurable electrical signal.
2. A protective housing
This enclosure protects the sensor and electronics from dust, humidity, corrosion, or extreme conditions. In hazardous areas, the housing may be ATEX-certified to comply with explosive atmosphere requirements.
3. Signal processing electronics
These electronics transform the raw signal generated by the sensing element into usable data.
4. A communication interface
The processed data is then transmitted to a control panel or monitoring system through communication protocols such as 4–20 mA, Modbus RS485, or HART.
The detection process takes place in three key steps:
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Detection: the target gas comes into contact with the sensing element.
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Conversion: the reaction produces an electrical signal proportional to the gas concentration.
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Transmission: the signal is sent to a monitoring system (portable device or fixed detection system).
The purpose is straightforward: provide real-time alerts when gas levels exceed preset thresholds to prevent explosions, toxic exposure, asphyxiation, or environmental contamination.
At Teledyne Gas & Flame Detection, gas sensors are integrated into portable devices or connected to fixed systems that protect entire industrial sites. The
BM25, for instance, is widely used for toxic gas monitoring. For large-scale installations, several sensors can be networked together through robust wireless architectures.
A gas sensor's value lies not only in detecting a specific gas, but also in how effectively it fits into a complete, reliable safety ecosystem.
The Main Types of Gas Sensors
Different sensing technologies exist, each suited to specific gases and industrial environments.
Electrochemical Sensors
Used primarily for toxic gases (CO, H₂S, etc.). They offer high sensitivity and accuracy, and are widely used in confined space monitoring.
Infrared (IR) Sensors
These sensors measure gas concentration by detecting the absorption of infrared light. They are ideal for CO₂ and hydrocarbons, offering long service life and excellent stability—often preferred in petrochemical environments.The GD10P is a prime example of a highly reliable and robust IR sensor for combustible gas monitoring.
NDIR Sensors (Non‑Dispersive Infrared)
NDIR (Non-Dispersive Infrared) sensors, widely used at Teledyne Gas & Flame Detection, enable reliable analysis of combustible gases.
Catalytic Sensors (Pellistors)
Designed to detect combustible gases such as methane, propane, and hydrogen. The sensor measures resistance changes caused by catalytic bead heating. Commonly used for explosion prevention on industrial sites.
Semiconductor Sensors
These sensors rely on conductivity variations in a sensitive semiconductor layer. They are cost‑effective and robust, making them suitable for multi‑gas monitoring.
MEMS Sensors
MEMS (Micro‑Electro‑Mechanical Systems) sensors combine micromechanical elements with integrated electronics. Advantages include:
- low power consumption
- compact size
- resistance to catalytic poisons
- suitability for portable or harsh environments
These sensing technologies are complementary and often used together to ensure optimal coverage based on each site's risks.
Industrial Applications of Gas Sensors
Gas sensors are essential safety components used across a wide range of industries, as for example:
- Oil & Gas: Monitoring refineries, petrochemical plants, and offshore platforms to detect leaks and prevent accidents.
- Chemical and Pharmaceutical Industries: Ensuring workers are not exposed to hazardous or toxic substances.
- Nuclear and Energy Sectors: Detecting hydrogen leaks with specialized equipment such as the Gasurveyor 700.
- Transport and Logistics: Securing tunnels, storage areas, and sensitive warehouse environments.
Beyond detection, maintenance, calibration, and long-term reliability are critical. Teledyne Gas & Flame Detection provides dedicated maintenance services to guarantee sensor performance and equipment lifetime.
Gas sensors are a cornerstone of industrial safety. Whether monitoring toxic, combustible, or greenhouse gases, each technology offers specific advantages suited to different applications.
Choosing the right sensor is essential, but so is partnering with a provider capable of delivering a comprehensive, reliable, and durable gas detection solution.
Teledyne Gas & Flame Detection offers a wide range of fixed and portable gas detectors, as well as advanced connected systems tailored to the most demanding environments.
Discover our full product portfolio to find the solutions best suited to your safety needs.
