Function And System Design; Measuring Principle - Endress+Hauser Cerabar PMP71B Technical Information

Measuring principle

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Function and system design

Metal process membrane
Standard device (without diaphragm seal)
1 Measuring element
2 Channel with fill fluid
3 Metal process membrane
p Pressure
The pressure deflects the metal process membrane of the sensor. A fill fluid transfers the pressure to
a Wheatstone bridge (semi-conductor technology). The pressure-dependent change in the bridge
output voltage is measured and evaluated.
Advantages:
• Can be used for high process pressures
• High long-term stability
• High overload resistance
• Secondary containment for enhanced integrity
• Significantly reduced thermal effect e.g. compared to diaphragm seal systems with capillaries
Device with diaphragm seal
1 Measuring element
2 Internal process membrane
3 Channel with fill fluid
4 Metal process membrane
p Pressure
The pressure acts on the process membrane of the diaphragm seal and is transferred from a
diaphragm seal fill fluid to the internal process membrane. The internal process membrane is
1
2
3
p
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2
3
4
p
Cerabar PMP71B
A0043089
A0043583
Endress+Hauser