COMMISSIONING
Part No.: 4417340 Revision 1 Service Manual 117
954 SmartServo FlexLine
If Relative pressure is selected, the value stored in the [Ambient Air
Pressure] entity is added to the measured pressure. If Absolute pressure
is selected, no factor is added. The final result is available in the [Primary
Value] entity.
NOTE: Absolute pressure is used in the density calculation; the relative
pressure is only displayed in P3 [Primary Value].
For the FCI-HT software to differentiate between a HART device
malfunction and a HART device not actually installed, P3 pressure has
the entity [P3 Installed] which must be set to either <Installed> if a P3
pressure HART device is actually fitted or <Not Installed> if a P3 pressure
HART device is not actually fitted. For example, in the case of free-
venting tanks, P3 would usually not be installed.
If the P3 pressure status is <Good Actual>, the P3 pressure value is also
stored in memory in the [Last Valid P3] entity, to allow recovery from a
power-down situation when a P3 pressure is not available.
If the measured P3 pressure is invalid (e.g. HART scan error), the
software will check the [P3 Installed] entity to determine if P3 is actually
fitted. If P3 is fitted, the software will check for a [Manual P3 Pressure] entity
value to be entered. If no manual P3 pressure value is entered, the [Last
Valid P3] is used in the density calculation. If no [Last Valid P3] is available,
an error will be reported.
If P3 pressure is not installed - in the case of free-venting tanks - a
default value of 0.0 for P3 pressure is used for density calculations.
The Secondary and Tertiary values of a P3 pressure HART device are
not converted, and they are simply translated from the HART device to
the FlexConn environment.
7.3.7.3.4 HIMS Density
To make HIMS density calculation possible, the relevant entity values
must be available. See also Figure 7-15
☛ Read also the Instruction Manual HIMS pressure measurement.
☛ Enter the appropriate values into the following entities:
• [Distance P1 to Zero Level]
• [Distance P3 to Zero Level]
• [Hydrostatic Deformation Level]
• [Hydrostatic Deformation Factor]
• [Local Gravity]
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