Differential pressure sensor
The differential pressure sensor is a pressure sensor that measures the difference between two absolute pressures, the differential pressure . The differential pressure sensor can consist of two measuring chambers that are hermetically separated from one another by a membrane . The deflection of the membrane is then a measure of the size of the differential pressure.
Differential pressure transmitter
The differential pressure transmitter is used to continuously measure pressure differences in liquids , vapors , gases and dusts . The hydrostatic level in a container or the mass flow through a pipeline can be calculated from the differential pressure . The saturation of a particle filter can also be determined in this way by measuring the differential pressure before and after the particle filter.
Measurement properties
If it is desired to measure a difference between two pressures, the system is subjected to the different process pressures from both the left and the right, whereby the membrane deflection reflects the pressure difference. In the case of aggressive media, a ceramic or metallic separating membrane is built in front of the actual measuring chamber so that these media cannot penetrate the measuring membrane and destroy it.
Areas of application
- gaseous and liquid media
- Heating technology
- Monitoring of filters and sieves
- process technology
- Building technology the blower door test
- Automotive technology
Measurement results
An electronic evaluation system transforms and amplifies the signal supplied by the pressure cell. The original signal is the difference in the capacities of both capacitors . With the applied alternating voltage , this difference in capacitance can be evaluated and converted into a measurement signal ( see capacitive sensor ).
An alternative is the silicon pressure sensor , which records the deformation using resistors attached to the membrane. This measuring circuit can also be operated with direct voltage .