Emerson Daniel 3415

For each non-failed chord, the interpolated proportion value used in Equation 4-9 is
calculated as follows:
• If the chord's velocity is surrounded by non-default (average velocity, average
proportion) data pairs, then the interpolated proportion is the linear interpolation
between the two data pairs
• If the chord's velocity has a non-default (average velocity, average proportion) data
pair on one side of it but not the other, then the interpolated proportion is the data
pair average proportion
• If there are only default (average velocity, average proportion) data pairs, then the
interpolated proportion is the corresponding bin's default average proportion value.
4.5 Volumetric flow rate
The Daniel 3410 Series Gas Ultrasonic Flow Meter meter provides three volumetric flow
rate values: raw, (expansion-corrected and/or profile-effect corrected) flow-condition, and
base- condition. Note that a positive volumetric flow rate indicates flow in the forward
direction whereas a negative volumetric flow rate indicates flow in the reverse direction.
4.5.1 Raw volumetric flow rate
The "raw" volumetric flow rate is calculated from the average gas flow velocity (wet-
calibration gas flow velocity) as shown in Equation 4-10
Raw volumetric flow rate Equation 4-10:


= 



2
4
 3600 /ℎ
where
Equation 4-10
Q
Raw
=
“raw” volumetric flow rate (m
3
/h) (QMeter)
V
WetCal
=
wet-calibration gas flow velocity (m/s) (AvgFlow)
π =
geometric constant, pi (dimensionless) (3.14159...)
D =
pipe inside diameter (m) (PipeDiam)
4.5.2 Flow-condition volumetric flow rate
The flow-condition volumetric flow rate is the result of applying expansion correction and
flow- profile correction to the raw volumetric flow rate as shown in Equation 4-11 subject to
the low- flow cut-off. If the resulting value is below the low-flow cut-off value, it is set to
zero. The low-flow cut-off volumetric flow rate (CutRate) is the specified low-flow velocity
threshold (ZeroCut) converted to a volumetric flow rate.
Measurement
26 3410 Series Gas Ultrasonic Flow meters