PMP71 datasheet(9/124 Pages) EH

9 / 124 page

Cerabar S PMC71, PMP71, PMP75

Endress+Hauser

Measuring principle

Devices with ceramic process isolating diaphragm (Ceraphire®)

A0020465

Air pressure (relative pressure sensors)

Ceramic substrate

Electrodes

Ceramic process isolating diaphragm

The ceramic sensor is an oil-free sensor, i.e. the process pressure acts directly on the robust ceramic

process isolating diaphragm and causes it to deflect. A pressure-dependent change in capacitance is

measured at the electrodes of the ceramic substrate and the process isolating diaphragm. The

measuring range is determined by the thickness of the ceramic process isolating diaphragm.

Advantages:

• Guaranteed overload resistance up to 40 times the nominal pressure (see "OPL" column in table)

→  12)

• The ultrapure 99.9% ceramic (Ceraphire®, see also "www.endress.com/ceraphire") ensures:

– Extremely high chemical durability

– Less relaxation

– High mechanical durability

• Suitable for vacuums

• Secondary containment for enhanced integrity

• Process temperatures up to 150 °C (302 °F)

Devices with metallic process isolating diaphragm

A0016448

Silicon measuring element, substrate

Wheatstone bridge

Channel with fill fluid

Metal process isolating diaphragm

PMP71

The process pressure deflects the metal process isolating diaphragm of the sensor and a fill fluid

transfers the pressure to a Wheatstone bridge (semiconductor technology). The pressure-dependent

change in the bridge output voltage is measured and evaluated.

PMP71 Datasheet(PDF) 9 Page - Endress+Hauser Group Services AG