Rockwell Automation 1734sc-IE4CH E+H Instruments via HART to PlantPAx User Manual - Manual (Page 120)

120 Rockwell Automation Publication PROCES-UM002A-EN-P - July 2014
Appendix H Cerabar S Pressure Transmitter
A Ceramic measuring diaphragm is used for the Cerabar S PMC71 (Ceraphire®).
The Ceramic sensor is a dry sensor, i.e. the process pressure acts directly on the
robust ceramic diaphragm and deflects it. A pressure-dependent change in
capacitance is measured at the electrodes of the ceramic carrier and the
diaphragm. The measuring range is determined by the thickness of the ceramic
diaphragm.
Advantages:
• Guaranteed overload resistance up to 40 times the nominal pressure
• Thanks to highly-pure 99.9% ceramic (Ceraphire®, see also
"www.endress.com/ceraphire")
– extremely high chemical resistance compared to Alloy
– less relaxation
– high mechanical stability
• Suitable for vacuums
• Second process barrier (Secondary Containment) for enhanced integrity
• Process temperature up to 150°C (302°F)
Item Description
1 Atmospheric vent (gauge pressure only)
2 Ceramic substrate
3 Electrodes
4 Ceramic diaphragm
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