3410 Series Gas Ultrasonic Meters Operations Manual
Section 4: Flow measurement
3-9000-777 Rev E
January 2018
Batch cycle processing
21
4.2.3
Batch cycle processing
Batch update period
Calculation updates performed by the meter, for deriving volume and velocity, are based on
batches of data samples collected from sequences of transducer firings. The batch update
period is dependent upon the user specified batch update period (
SpecBatchUpdtPeriod
) and the
stack size (
StackSize
) as shown in
Table 4-1
. The Standard batch update period is the default. The
actual batch update period is readable via the
BatchUpdatePeriod
data point.
Emission rates
The emission rate is the period between firing two different transducers. The stacked emission
rate is the period between consecutive firings of a single transducer when stacking is used (i.e.,
the stack size is not set to None).
The actual emission rates used (readable via the
EmRateActual
and
StackEmRateActual
data
points) are functions of the desired emission rates, meter type, firing sequence, stack size, and
pipe diameter.
The user specifies the desired emission rates via the
EmRateDesired
and
StackEmRateDesired
data points. If a desired emission rate is set to zero, the meter uses the fastest possible emission
rate which can be as short as is 2 milliseconds. Otherwise, the meter uses the fastest possible
emission rate that is
not less than
the desired value. We recommend setting the Filter to the OFF
position.
The
Signal Analyzer
(
Meter|Signal Analyzer
) is used to configure the
EmRateDesired
and
StackEm-
RateDesired.
These values are set to zero to achieve the most transducer firings per batch
update.
Table 4-1 Actual meter update period
Stacksize
1 (None)
2
4
8
16
SpecBatchUpdtPeriod
Rapid
(250 ms)
0.25 sec
N/A
N/A
N/A
N/A
Standard
(1000 ms)
1 sec
1 sec
1.5 sec
3 sec
5 sec
