Hydrogen (H2) measurement for electrolyser

Mechatest design for new electrolyser unit a Hydrogen (H2) gas measurement solution (also known as H2 in O2 wet gas sensor) that allows for analysis of the wet gas Hydrogen (H2) stream in Oxygen (O2) composition.

The output of the electrolyser is Hydrogen (H2) and Oxygen (O2) as a gas composition and might be saturated with water vapor. To take in a wet gas a Hydrogen (H2) sample is not easy, most sensors for this typical measurement in this acceptable price range are mostly not suitable for wet gasses. 

Based on our experience we designed solution with fallback probe, membrane filtration with liquid blocker, and prevent the Hydrogen (H2) sensor from harmfull wet gas and extend lifetime much more.


Hydrogen (H2) is an explosive and dangerous gas, humans and the environment are subjected to high safety risks, the Mechatest Hydrogen (H2) measurement solution is suitable for explosion dangerous areas. 

We deliver general purpose and model for explosion proof area Ex SIL-2.

There are two pressure options, low pressure up to 10 bar or high pressure model for up to 55 bar.

Hydrogen wet gas measurement range 0 – 4 vol. % (other ranges on request).


As a fuel, green Hydrogen (H2) gas has the future against the Hydrogen made from fossil fuels. The green Hydrogen will be seen as the alternative to natural gas needs. Hydrogen from fossil fuels has been used safely for many decades in a wide range of applications, including in the food, metal, glass and chemical industries. 

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Frames Electrolyser System with Mechatest Hydrogen measuring system

Hydrogen sample wiki

At standard temperature and pressure, hydrogen is a colorless, odorless, tasteless, non-toxic, nonmetallic, highly combustible diatomic gas with the molecular formula H2.
Since hydrogen readily forms covalent compounds with most nonmetallic elements, most of the hydrogen on Earth exists in molecular forms such as water or organic compounds. 

  • Main hazards: Flammable, Explosive
  • Phase: Gas
  • Density: 0.000082 (20 °C) g/cm3
  • Boiling Point: -253 °C
  • Explosive limits: 4 – 75 %
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Hydrogen (H2) measurement in wetgas electrolyser

H2 Generation Section

In collaboration with technology partners, Frames was able to offer one of the largest commercially proven electrolysis stacks currently on the market. The megawatt scale stack has the best-in-class price-performance in the

production range from 30 Nm3/h to 400 Nm3/h within an extremely compact single assembly. 

Mechatest support Frames with the Hydrogen and Oxygen gas measurement.



H2 Conditioning Section

The hydrogen produced by the electrolysis stacks will contain both liquid water and water vapor. The hydrogen dew pointing section is designed to remove moisture and upgrade the produced hydrogen to a purity of 5.5, which is an equivalent gas purity of 99.9995%. To meet the purity requirements, oxygen is removed in a catalytic reactor, and hydrogen is dried using a molecular sieve. To run the unit continuously, the molecular sieve vessels are installed in duplex configuration (duty/regeneration). One vessel is in operation while the other one is being regenerated. 

H2 Storage Section

The system can be supplied with an optional

storage section to allow produced hydrogen to be stored through compression, liquefaction or via liquid organic hydrogen carrier (LOHC).

Electrolyser Green Hydrogen (H2) Gas Measurement

The major challenge in measuring hydrogen samples in wet gas in an electrolyser system is to protect the hydrogen sensor and ensure a long service life and high quality measurement.
We have improved our Hydrogen sampling systems for gas by:

  • Creating closed loop systems emission free which provide a safe, controlled environment
  • Suitable for high pressure process application
  • Simplifying designs, making the sampling of liquid and gas more efficient
  • Proper discharge of excess liquid or gas prevents unwanted pressure build-up in the system

These modern solutions simply regard the sampling systems themselves. Our worldwide reputation rests on the combination of excellent Hydrogen measurement systems, and professional services by our team of specialists.


Enjoy the full benefits of an experienced team of passionate professionals

Mechatest employees possess decades of experience and knowledge. All of which is at your disposal when your sampling system needs adaptations, maintenance or repairs. Our staff has high-tech equipment at their disposal, thus increasing their efficiency even more. We are even capable of designing and manufacturing in accordance with foreign codes and standards.


Start improving by sampling process today

Why wait any longer? Improvement starts today if you pick up the phone and call us at +31 (0)15 – 310 51 83. Our staff provides you with all the information you need to make an informed decision and choose the best sampling systems for liquid or liquefied gas.


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