Emerson Daniel 3415

Flow-condition volumetric flow rate Equation 4-11:


= 






where
Equation 4-11
Q
Flow
=
flow-condition volumetric flow rate (m
3
/h) (QFlow)
Q
Raw
=
“raw” volumetric flow rate (m
3
/h) (QMeter)
ExpCorr
P
=
expansion correction factor due to pressure (dimensionless) (ExpCorrPressure)
calculated as shown in
ExpCorr
T
=
expansion correction factor due to temperature (dimensionless)
(ExpCorrTemperature) calculated as shown in
CorrFctr =
profile-effect correction factor (CorrectionFactor) calculated as shown in
4.5.3 Pressure-effect expansion correction
The meter is capable of correcting the raw volumetric flow rate for the effect of pipe
expansion due to pressure changes.
Note that for the pressure-effect expansion correction factor to be calculated, the
correction must be enabled (via the EnableExpCorrPress data point) and the flow-
condition pressure must be available (i.e., the EnablePressureInput data point must be set
to 'Live'(1) or 'Fixed'(2), see Section 5.9.3). The pressure-effect calculation is shown in . If the
pressure-effect expansion correction factor is not calculated, it is set to 1.0.
Pressure-effect expansion correction Equation 4-12:


= 1 + 3 ×  × 
, 
 

Equation 4-12
ExpCorr
P
=
expansion correction factor due to pressure (dimensionless) (ExpCorrPressure)
ß =
pipe linear expansion coefficient due to temperature (MPaas-1) (StrainPerUnitStress)
calculated as shown in
P
abs,f
=
flow-condition absolute pressure (MPaa) (AbsFlowPressure) calculated as shown in
Equation 4-16
P
ref
=
reference absolute pressure (MPaa) (0.101325MPaa) reference temperature for the
pipe linear expansion coefficient (K)
4.5.4 Temperature-effect expansion correction
The meter is capable of correcting the raw volumetric flow rate for the effect of pipe
expansion due to temperature changes.
Measurement
Operations manual 27