How to measuring pressure under 16mbar?
With pressures under 16 mbar, diaphragm pressure gauges hit their limits. For this case, their diaphragms would have to be exceptionally thin in order to achieve the required elasticity. Then, however, they would no longer remain reliably stable. This problem can be solved, though, with a special variation of the diaphragm pressure gauge: the capsule pressure gauge.
Capsule elements consist of two diaphragms welded together, which are generally loaded with pressure from the inside. This results in a double diaphragm travel. In this way, even the lowest of pressures can be measured without reducing the wall thickness. However, since the pressure chamber is not self-draining, capsule elements are not suitable for applications with liquid media.
