Pressure transducer that can measure the absolute pressure. For this purpose the side opposite the pressure to be measured is hermetically sealed as a reference chamber (e.g. with a glass plate or glass bushing). The reference pressure defined in this manner in the chamber can be a vacuum, but is not necessarily a vacuum. It is sufficient if the pressure is stable. The referencing of the measured signal to absolute zero is then undertaken electronically.
Fluidlexikon