KROHNE Summit 8800 Vol 2 - Manual (Page 25)

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08/2013 - MA SUMMIT 8800 Vol2 R02 en
SUMMIT 8800 METERING PRINCIPLES 03
• Accuracy: By averaging the transmitter values.
• Redundancy: If one transmitter fails, the other value may be used.
• Diagnostics: A warning can be given if there is a deviation between the transmitters.
For diagnostics 2 transmitters can be used, but it is not possible to determine which one is cor-
rect. For that reason 3 dP transmitters may be used.
The SUMMIT also can have 1 to 3 dP transmitters for 1 to 3 ranges, so 1 to 9 dP transmitters in
total.
3 .3 .1 Orifice Plate
A flat circular plate with a hole, mounted inside the pipe that causes the fluid to push through a
smaller diameter.
Figure 6 Orifice meter and plate
This is the most commonly used type of meter.
Classical venture or Herschel venturi
Consists of a tapering in the pipe.
Figure 7 Venturi tube layout