Gas sensors – find manufacturers and suppliers

Gas sensors, or gas detectors, are electronic components that detect the concentration of certain gases in the ambient air or in gas mixtures and convert them into an electrical signal.

They are indispensable in safety, environmental and automation applications.

Below you will find how different types of gas sensors work, their areas of application and trends and developments in this field:

How gas sensors work:

There are several different types of gas sensors, depending on the physical or chemical operating principle. The most important types are listed below:

1. Semiconductor gas sensors (MOS sensors):
   Principle: Change in the electrical resistance of a semiconductor on contact with a gas.
   Material: Mostly tin oxide (SnO₂).
   Typical gases: CO, CH₄, H₂, LPG.
   Advantages: Inexpensive, compact, low maintenance.
   Disadvantages: Cross-sensitivities, temperature-dependent.
2. Electrochemical gas sensors:
   Principle: Chemical reaction of the gas at an electrode that generates a current flow.
   Typical gases: CO, NO₂, O₃, SO₂.
   Advantages: Very selective, good accuracy.
   Disadvantages: Limited service life (1-3 years), sensitive to environmental influences.
3. Infrared gas sensors (NDIR):
   Principle: Measurement of the absorption of infrared radiation by certain gases.
   Typical gases: CO₂, CH₄, HCs.
   Advantages: High accuracy, no consumption of measuring material.
   Disadvantages: More expensive, larger design.
4. Photoionization detectors (PID):
   Principle: Ionization of molecules by UV light → measurement of the current.
   Typical gases: VOCs (volatile organic compounds), solvents.
   Advantages: Very sensitive (ppb range).
   Disadvantages: Expensive, sensitive to moisture.
5. Catalytic sensors:
   Principle: Combustion of combustible gases on a catalyst → temperature rise → resistance change.
   Typical gases: CH₄, propane, hydrogen.
   Advantages: Robust, reliable with explosive gases.
   Disadvantages: Consumption of oxygen, less selective.

Use of gas sensors:

1. Safety monitoring:
Carbon monoxide alarms in households.
Explosion protection in industrial plants.
Gas leak detection in refineries.
Important gases: CO, CH₄, H₂, propane, LPG.

2. Environmental monitoring:
Air quality measuring stations
Smog alarm systems
Emission control
Important gases: NOₓ, SO₂, CO₂, O₃, VOCs

3. Medicine and biotechnology:
Breath gas analysis (e.g. for breathalyzers or diagnostic devices)
CO₂ measurement for ventilators
Important gases: CO₂, NH₃, acetone

4. Agriculture and food:
monitoring of ripening processes (e.g. ethylene)
Storage of fruit and vegetables (CO₂, O₂)
Fermentation control
Important gases: CO₂, ethylene, NH₃

5. Automotive industry:
Exhaust gas control (lambda probe)
Indoor air quality
Important gases: CO, NOx, CO₂, HC

6. Smart Home & IoT:
Indoor air monitoring
Smart ventilation control
Smoke and gas warning systems
Sensors: often in combination with temperature, humidity and particle measurement

Trends and developments in the field of gas sensors:

• Miniaturization: MEMS gas sensors for portable devices and wearables.
• Multi-sensor technology: Combined sensors for several gases.
• AI-supported sensor technology: Recognition of patterns and gas mixtures through machine learning.
• Wireless systems: Integration into IoT platforms for remote monitoring.

Gas sensors are central components in many safety and environmentally relevant applications. Depending on the measuring principle, they offer different strengths and weaknesses in terms of accuracy, selectivity, costs and operating environment.
Overall, gas sensors are indispensable for ensuring safety, health and environmental protection in various areas of life. The choice of the right sensor type depends heavily on the specific application.

Below you will find an overview of the most important criteria that you should pay attention to when purchasing gas sensors:

When purchasing gas sensors, careful selection is crucial to ensure long-term safety, accuracy and cost-effectiveness.

• Before a sensor type is even selected, it must be clear which gases are to be detected.
• It is also important to know whether the gases are toxic, explosive or environmentally relevant.
• Some sensors are very specific, others react to a wide range of gases - this can be both an advantage and a disadvantage.
• Example: An electrochemical sensor is useful for CO, whereas an NDIR sensor is more suitable for CO₂.
• The environment in which the sensor is to operate has a significant impact on its service life and performance.
• Sensors react differently to extreme environmental conditions such as temperature and humidity.
• The presence of dust, vapors or chemicals can impair or destroy sensors.
• In hazardous areas, sensors with ATEX or IECEx certification are mandatory.
• The sensor must be able to reliably measure the expected concentrations:
• The measuring range must match the typical concentrations of the target gas.
• A low detection limit is particularly important for toxic gases or VOCs (e.g. in the ppb range).
• Resolution and linearity are particularly relevant for precise measurements, especially in process measurement technology.
• Many sensors react not only to the target gas, but also to similar gases. This cross-sensitivity can lead to incorrect measurements.
• Manufacturer data sheets often indicate how strongly a sensor reacts to other gases.
• Possible remedy by calibration with target gas or use of filter systems.
• Gas sensors are subject to ageing and chemical wear - maintenance costs therefore play a major role.
• What are the calibration intervals? Some sensors require monthly calibration, others only annual calibration.
• What is the service life? Electrochemical sensors often only have a service life of 2-3 years; NDIR sensors last considerably longer.
• The interchangeability of the sensor unit is an advantage for long-term operation.
• Depending on the application, the type of data acquisition is decisive:
• Digital sensors often offer higher precision and lower susceptibility to interference.
• Ensure compatibility with existing systems, e.g. Modbus, CAN, 4-20 mA, LoRa, MQTT.
• Smart features such as self-diagnosis, automatic calibration or temperature compensation increase operational reliability.
• Certain standards are prescribed in many industries, e.g:
• ATEX/IECEx for potentially explosive atmospheres.
• ISO/EN standards: For environmental measurement or in the field of occupational safety.
• Medical approvals: For use in diagnostics or ventilation.
• It's not just the purchase price that counts. What is important is how expensive the sensor is over its entire service life.
• Technologies such as IoT and AI are changing the use of sensors. When making new purchases, you should pay attention to modularity and expandability.
• A reliable manufacturer or supplier not only offers a product, but also
• Technical documentation, training for calibration and maintenance, fast spare parts supply and telephone support or remote maintenance.

The purchase of gas sensors requires a holistic view of technical, operational and economic aspects. A cheap sensor can become expensive if it frequently fails or measures incorrectly. In the long term, high-quality, well-supported solutions that are precisely tailored to the respective application are worthwhile.

Gas sensors can be obtained from various suppliers. Comprehensive information about manufacturers and suppliers of Gas sensors from all over the world can be found on Exportpages.