Emerson Daniel 3410 Series User Manual

34 Base-condition volumetric flow rate
Section 4: Flow measurement 3410 Series Gas Ultrasonic Meters Operations Manual
January 2018 3-9000-777 Rev E
4.5.7 Base-condition volumetric flow rate
The base-condition volumetric flow rate is the result converting the flow-condition volumetric
flow rate to the base pressure-temperature condition. This conversion requires (1) AGA8
calculations to be either performed internally (i.e., by the meter) or externally (with the
resulting compressibilities specified to the meter via the
SpecZFlow and SpecZBase data points),
and (2) the flow-condition temperature and pressure to be live or fixed. If AGA8 calculations are
not performed (i.e., neither internally nor externally) or the flow-condition temperature and/or
pressure are/is not enabled, then the base-condition volumetric flow rate is set to zero.The base-
condition volumetric flow rate is calculated as shown in Equation 4-15.
Equation 4-15 Base-condition volumetric flow rate
where
4.5.8 Volume
The Daniel 3410 Series Gas Ultrasonic Flow Meter 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.
=
“raw” volumetric flow rate (m
3
/h) (QMeter)
=
flow-condition volumetric flow rate (m
3
/h) (QFlow)
= base-condition absolute pressure (MPaa) (PBase)
= flow-condition absolute pressure (MPaa) (AbsFlowPressure)
calculated as shown in Equation 4-10
= base-condition temperature (K) (TBase)
= flow-condition temperature (K) (FlowTemperature)
= base-condition compressibility factor (ZBase)
= flow-condition compressibility factor (ZFlow)
Q
Base
Q
Flow
P
abs f,
P
abs b,
---------------


T
b
T
f
-----


Z
b
Z
f
------


=
Q
Base
Q
Flow
P
abs b,
P
abs f,
T
b
T
f
Z
b
Z
f

Emerson Daniel 3410 Series Specifications

General

Brand	Emerson
Model	Daniel 3410 Series
Category	Measuring Instruments
Language	English