What is a hydrogen sensor?
A hydrogen sensor is a device used to detect the presence of hydrogen gas in an environment. Hydrogen sensors are important for safety, industrial processes, and environmental monitoring due to the highly flammable nature of hydrogen. They help prevent potential hazards by providing early warnings of hydrogen leaks and ensuring that hydrogen levels remain within safe limits.

Working principle of Hydrogen sensor

Hydrogen sensors operate on a variety of principles and technologies. The most common types of hydrogen sensors include:

Electrochemical Hydrogen Sensor

The electrochemical hydrogen sensor operates based on the oxidation–reduction (redox) principle. When hydrogen gas (H2) enters the sensor through a diffusion membrane, it comes into contact with the working electrode, where an oxidation reaction occurs, producing hydrogen ions and electrons. These electrons then flow through an external circuit to the counter electrode, where a reduction reaction takes place, generating an electrical current proportional to the hydrogen concentration in the environment. This current signal is then converted into a voltage or digital output for display or transmission to a monitoring system.

Catalytic Combustion Hydrogen Sensor

The catalytic combustion hydrogen sensor operates on the principle of hydrogen oxidation on a catalytic surface. When hydrogen gas comes into contact with a sensing element coated with a catalyst such as platinum or palladium, a low-temperature combustion reaction occurs, releasing heat proportional to the hydrogen concentration in the air. The resulting temperature rise changes the resistance of the sensing element, and this resistance variation is converted into an electrical signal corresponding to the hydrogen concentration, which is then displayed or transmitted to a control unit.

Metal-oxide semiconductor (MOS) hydrogen sensor

The metal-oxide semiconductor (MOS) hydrogen sensor operates based on the principle of resistance change in a semiconductor layer when exposed to hydrogen gas. The sensing element is typically made from metal oxides such as SnO2, ZnO, or TiO2, which can adsorb gas molecules on their surface. When hydrogen is present, it reacts with the adsorbed oxygen ions on the oxide surface, reducing their concentration and thereby altering the density of free charge carriers in the material. This results in a change in the electrical resistance of the sensor, which is proportional to the hydrogen concentration in the air and is converted into an electrical signal for display or transmission to a

Thermal Conductivity Hydrogen Sensor

The thermal conductivity hydrogen sensor works based on the measurement of changes in gas thermal conductivity. Hydrogen has a significantly higher thermal conductivity than most other gases, so when it is present in a gas mixture, it alters the heat dissipation rate of the heated sensing element. This change in temperature causes a variation in the element’s resistance, which the sensor then converts into an electrical signal proportional to the hydrogen concentration in the air.

Optical Hydrogen Sensor

The optical hydrogen sensor operates on the principle of optical property variation in the presence of hydrogen. When hydrogen gas interacts with an optically sensitive material (typically a thin metal film or catalytic compound), it changes the absorption, reflection, or transmission characteristics of the material. These changes are detected by the light source and photodetector within the sensor and converted into an electrical signal proportional to the hydrogen concentration in the environment.

Applications of hydrogen sensors
Hydrogen sensors are widely used across industrial, environmental, automotive, medical, and research fields to ensure safety, improve operational efficiency, and comply with international safety standards.

Industrial Safety

In industrial applications, hydrogen sensors play a critical role in detecting leaks and preventing explosion risks at chemical plants, refineries, and gas storage facilities. These sensors continuously monitor hydrogen concentration in the air, providing early warnings when levels exceed safe thresholds to protect systems and personnel. They are also integrated into hydrogen fuel cells and clean energy systems to ensure stable and completely safe operation.

Environmental Monitoring

In the environmental field, hydrogen sensors are used to detect hydrogen emissions from industrial processes and natural sources, helping to control gas emissions and maintain ecological safety. These devices are also applied in air quality monitoring within areas that produce or use hydrogen, enabling the detection of even small leaks that traditional methods may overlook.

Automotive Industry

In the automotive industry, hydrogen sensors are essential components in hydrogen fuel cell vehicles (FCVs). They help detect hydrogen leaks within the fuel system, ensuring maximum safety for drivers and passengers. Additionally, hydrogen sensors are used in research, development, and testing of hydrogen-powered engines, supporting improvements in performance, reliability, and clean vehicle technology.

Medical Applications

In the medical field, hydrogen sensors are applied in breath analyzers to detect gastrointestinal disorders and other health conditions based on hydrogen concentration in exhaled breath. They are also used in biomedical laboratories to monitor and analyze hydrogen levels in research environments, supporting medical diagnostics and clinical testing.

Research and Development

Hydrogen sensors are extensively used in laboratories focused on material science, energy, and chemistry to study hydrogen behavior, reactions, and kinetics under various conditions. Furthermore, they play an important role in the development of advanced hydrogen storage, transportation, and utilization technologies, contributing to the global transition toward a sustainable green energy economy.

Sensors Vietnam is one of the leading importers of industrial sensors and equipment in Vietnam. If you are looking for a formaldehyde sensor, please contact Sensors Vietnam for consultation and quotation.

E2618-LEL-H2-W-24VDC – EVIKON Hydrogen Gas Sensor
Measurement range: 0...100% LEL
Output: 2 × 4–20 mA / 0–10 V; RS485
Power supply: 24 VDC

SV-3605 – PROSENSE Hydrogen Gas Sensor
Measurement range: 0–100% LEL
Output: 4–20 mA / RS-485 / Relay
Equipped with LCD display

SV-3604C – PROSENSE Hydrogen Gas Sensor
Measurement range: 0–2000 ppm
Output: 4–20 mA / RS-485 / Relay
Equipped with LCD display

SV-3604B – PROSENSE Hydrogen Gas Sensor
Measurement range: 0–1000 ppm
Output: 4–20 mA / RS-485 / Relay
Equipped with LCD display

SV-3604 – PROSENSE Hydrogen Gas Sensor
Measurement range: 0–500 ppm
Output: 4–20 mA / RS-485 / Relay
Equipped with LCD display

For more details: https://cambien.com.vn/cam-bien-khi-de-chay