Measuring Cell For Gauge Pressure - Siemens SITRANS P DS III Operating Instructions Manual

Description
3.7 Principle of operation
● Flange connection in accordance with EN 61518
● Flush-mounted process connections
3.7.3.1

Measuring cell for gauge pressure

①
②
③
④
Image 3-5
The inlet pressure (p
④
and the fill fluid
resistance of the four piezoresistors (bridge circuit) of the gauge pressure sensor. The
change in the resistance causes a bridge output voltage proportional to the inlet pressure.
Pressure transmitters with spans ≤ 6.3 MPa measure the inlet pressure against atmosphere,
those with spans ≥ 16 MPa the inlet pressure against vacuum.
30
Reference pressure opening
Measuring cell
Process connection
Seal diaphragm
Function chart of measuring cell for gauge pressure
) is transferred to the gauge pressure sensor
e
⑤
, displacing its measuring diaphragm. The displacement changes the
⑤
Filling liquid
⑥
Gauge pressure sensor
p Inlet pressure
e
⑥
via the seal diaphragm
SITRANS P DS III/P410 with PROFIBUS PA
Operating Instructions, 02/2016, A5E00053276-08