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Reference, Installation, and Operations Manual Section 6: Meter operation
3-9000-743 Rev S June 2013
Volumetric flow rate 199
Profile-effect correction
JuniorSonic
TM
meters (device numbers 3410, 3420, and 3450) require profile-effect correction.
All other meters do not require profile-effect correction and the profile-effect correction factor
is set to 1.
For meter types that require profile-effect correction, the correction factor can be either user-
specified or meter-calculated depending upon the value of the SpecCorrectionFactor data
point: if set to 0.0, then the correction factor is meter-calculated; if set within [0.90, 1.05], then
the specified value is used.
Calculating the meter factor requires that the flow-condition pressure and temperature be live
or fixed and that the AGA8 calculations are performed either internally or externally. If the
profile-effect correction factor is to be meter-calculated but either the flow-condition pressure
and/or temperature are/is disabled or the AGA8 calculations are not performed, then the flow-
condition correction factor is set to the default value of 0.95. Otherwise, it is calculated as
shown in Equation 6-17.
Equation 6-17 Profile-effect correction factor
where
Reynolds number
Reynolds Number is a dimensionless value that represents the nature of the gas flow within the
pipe. Although the primary reason for calculating Reynolds Number is for JuniorSonic
TM
meter
profile-effect correction, the value is calculated for all meter types.
Reynolds Number is calculated as shown in Equation 6-18.
=
flow-profile correction factor (CorrectionFactor)
=
pipe wall roughness (m) (WallRoughness)
=
pipe inside diameter (m) (PipeDiam)
=
Reynolds Number (dimensionless) (ReynoldsNumber)
calculated as shown in Equation 6-18
CorrFctr 1
0.242
0.2703
WR
D
in
---------
0.835
Re
0.8
-------------
+
log
------------------------------------------------------------
+=
CorrFctr
WR
D
in
Re