When pressure sensors come into contact with hydrogen, this often results in difficulties. Unfortunately, I frequently notice in my own job that our customers are not aware of this prior to use. This is exactly why they often usually do not even tell us that their medium contains hydrogen. We only find out when we get a complaint. But why do we get yourself a complaint? Why is especially Calm to pressure sensors?
A basic rule is that a large number of metals become brittle when subjected to hydrogen. Hydrogen atoms that diffuse in to the metal grid change the strength of the material. In the worst case, this results in cracks in the material. Or even to put it simply, the pressure sensor starts leaking or is completely destroyed. In the case of pressure sensors, specifically thin membranes required for measuring pressure play a decisive role. Buy can not only penetrate the metal, but also go through it by diffusion.
It has several effects: When piezoresistive measuring principles are employed, it becomes critical if hydrogen reacts with the inner transmission medium or accumulates there. Pas 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 least temporarily, resulting in a falsification of the measurement signal.
However, the consequences described above occur in various materials differently. This means that the effects of hydrogen could be lowered substantially by selecting suitable materials.
Note
More info on our pressure sensors and on the subject of hydrogen can be found on the WIKA website. If you are using hydrogen because the medium, your contact will gladly recommend an optimum solution for the application.