10
3 Product description
VEGABAR 29 • Two-wire 4 … 20 mA
57087-EN-210301
1
3
4
2
Fig. 4: Configuration of the measuring system with piezoresistive sensor ele
-
ment
1 Sensor element
2 Base element
3 Transmission liquid
4 Process diaphragm
Strain gauge (DMS) sensor element
For measuring ranges above 250 bar, a strain gauge (DMS) sensor
element (dry system) is used.
1
2
3
Fig. 5: Configuration of the measuring system with strain gauge (DMS) sensor
element
1 Sensor element
2 Process diaphragm
3 Pressure cylinder
Relative pressure
: the measuring cell is open to the atmosphere.
The ambient pressure is detected in the measuring cell and compen-
sated. It thus has no influence on the measured value.
Absolute pressure
: the measuring cell contains vacuum and is
encapsulated. The ambient pressure is not compensated and does
hence influence the measured value.
The measuring system is completely welded and thus sealed against
the process.
The process fitting is sealed against the process by a suitable seal. It
must be provided by the customer, depending on the process fitting
also included in the scope of delivery, see chapter "
Technical data
", "
Materials and weights
".
Pressure types
Seal concept