Hydrogen and pressure sensors ? What must be observed?

When pressure sensors touch hydrogen, this often results in difficulties. Unfortunately, I very often notice in my job our customers are not aware of this ahead of use. That is why they often do not even reveal that their medium contains hydrogen. We only find out when we get a complaint. But why do we get a complaint? Why is especially hydrogen so critical to pressure sensors?
A basic rule is that numerous metals become brittle when subjected to hydrogen. Hydrogen atoms that diffuse into the metal grid change the strength of the material. In the worst case, this results in cracks in the material. Or to put it simply, the pressure sensor starts leaking or is completely destroyed. In the case of pressure sensors, specifically thin membranes necessary for measuring pressure play a decisive role. Atomic hydrogen will not only penetrate the metal, but additionally go through it by diffusion.
This has several effects: When piezoresistive measuring principles are employed, it becomes critical if hydrogen reacts with the internal transmission medium or accumulates there. This initially only falsifies the measurement results, but can down the road also result in complete destruction of the sensor in individual cases. The addition of hydrogen also changes the instrumentation characteristics of the resistance structures of the measurement bridge of thin-film sensors. Despite being reversible, this technique results in a detuning of the bridge at the very least temporarily, producing a falsification of the measurement signal.
However, เกจวัดน้ำยาแอร์refco described above occur in different materials differently. Because of this the consequences of hydrogen can be lowered substantially by selecting suitable materials.
Note
More info on our pressure sensors and on the subject of hydrogen are available on the WIKA website. If you are using hydrogen because the medium, your contact will gladly recommend an optimum solution for the application.

Leave a Comment