Emerson Daniel 3410 Series Operation Manual page 29

Operations manual
DAN-20057316
L
chord
X
t
1
MeanTmH1)
t
2
MeanTmH2)
Important
Note that a positive chord gas velocity indicates flow in the forward direction whereas a
negative chord gas velocity indicates flow in the reverse direction.
4.4.1 Average sound velocity
The Average Sound Velocity is calculated as the average of the active chord sound velocity
measurements as shown in the equation below:
Equation 4-3: Average sound velocity
where
C
C
NumActiveChords = number of active chords
4.4.2 Optional AGA10 sound velocity calculation and
comparison
The Daniel 3410 Series Gas Ultrasonic Flow Meter offers an option to calculate the sound
velocity (using AGA10 equations and gas property data) and compare the result to the
meter- measured sound velocity on an hourly basis.
This feature is enabled via the AGA10 Key (see
The gas property data required for using this feature can be specified via data points or
optionally read from a Daniel GC
Detailed Method must be selected (via the HCH_Method data point,
Chromatograph
AGA10 calculations require AGA8 Detailed method calculation intermediate results).
Every five seconds the meter updates the AGA10-calculated sound velocity. This value is
readable via the AGA10SndVel data point and the calculation status value is readable via
the AGA10SndVelStatus data point. The status values are as listed in the table below:
Table 4-2: AGA10 calculation status
AGA10SndVelStatus value
0
1
Model 3418 GUSM
= chord "L" dimension (m) (LA ... LH)
= chord "X" dimension (m) (XA ... XH))
chord
= chord average transit time in the upstream direction (s) (MeanTmA1 ...
= chord average transit time in the downstream direction (s) (MeanTmA2 ...
= average sound velocity (m/s) (AvgSndVel)
Avg
= chord average sound velocity (m/s) (SndVelA... SndVelH)
chord
parameters) in order for the AGA10 calculations to be performed (as the
∑ ActiveCℎords • C cℎord
c =
Avg
NumActiveCℎords
AGA10 key (sound velocity
(Configure Gas Chromatograph
Description
Calculation OK (no errors)
Calculation not performed as the feature is not enabled (see
Configure optional keys). AGA10SnVel is set to zero.
Measurement
January 2019
calculation)).
parameters). The AGA8
Configure Gas
29