Siemens SITRANS P300 Operating Instructions Manual page 25

Measuring cell for absolute pressure, front-flush membrane
Figure 3-9
(1)
(2)
(3)
(4)
(5)
p
e
The input pressure (p
diaphragm (3) and the fill liquid (4), displacing its measuring diaphragm. The displacement
changes the resistance value of the four piezo resistors in the measuring diaphragm in a
bridge circuit. The change in the resistance causes a bridge output voltage proportional to
the input pressure.
SITRANS P300 with HART communication
Operating Instructions, 06/2005, A5E00359579-02
Function chart of measuring cell for absolute pressure (front-flush)
Measuring cell
Process connection
Separating diaphragm
Fill liquid
Absolute pressure sensor
Input pressure
) is transferred to the absolute pressure sensor (6) via the seal
e
Description
3.6 Mode of operation
3-11