Emerson Daniel 3415

Base-condition volumetric flow rate Equation 4-16:


= 


, 

, 








where
Equation 4-16
Q
Base
=
“raw” volumetric flow rate (m
3
/h) (QMeter)
Q
Flow
=
flow-condition volumetric flow rate (m
3
/h) (QFlow)
P
abs,b
=
flow-condition absolute pressure (MPaa) (AbsFlowPressure) calculated as shown in
Section 4.5.3.
T
b
=
base-condition temperature (K) (TBase)
T
f
=
flow-condition temperature (K) (FlowTemperature)
Z
b
=
base-condition compressibility factor (ZBase)
Z
f
=
flow-condition compressibility factor (ZFlow)
4.5.8 Volume
The Daniel 3410 Series Gas Ultrasonic Flow Meter provides forward and reverse volume
accumulators for each of the three volumetric flow rate values: raw, flow-condition (raw
with expansion and/or profile correction), and base-condition.
Each volume accumulator is actually stored as a data pair: (64-bit unsigned integer
portion, 32-bit floating point fractional portion). For example, a volume of 12345.750 m
3
is stored as 12345 m
3
for the integer portion and 0.750 m
3
as the fractional portion. Note
that while a volumetric flow rate can be positive (indicating forward flow) or negative
(indicating reverse flow), the volume accumulators are always positive values.
The non-volatile volume accumulator data points are as listed in the table below:
Volume accumulation data pointsTable 4-3:
Volumetric
flow rate type
Forward Direction Reverse direction
Integer Fraction Integer Fraction
Raw PosVolUncorr PosVolUncorrFrac NegVolUncorr NegVolUncorrFrac
Flow-condition PosVolFlow PosVolFlowFrac NegVolFlow NegVolFlowUncorr
Base-condition PosVolBase PosVolBaseFrac NegVolBase NegVolBaseUncorr
Measurement
30 3410 Series Gas Ultrasonic Flow meters