When pressure sensors touch hydrogen, this often results in difficulties. Unfortunately, I very often notice in my own job our customers have no idea 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 a lot of metals become brittle when exposed 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 to put เกจวัดแรงดันลมดิจิตอล , the pressure sensor starts leaking or is totally destroyed. In the case of pressure sensors, specifically thin membranes required for measuring pressure play a decisive role. Atomic hydrogen can not only penetrate the metal, but also pass 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. This initially only falsifies the measurement results, but can down the road also lead to 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 leads to a detuning of the bridge at the very least temporarily, producing a falsification of the measurement signal.
However, the consequences described above occur in different 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 are available on the WIKA website. If you are using hydrogen as the medium, your contact will gladly recommend an optimum solution for your application.