Technical Manual
Page 34
CODEL
OPS.109
Issue : B
Rev. : 1
Date : 23/10/13
Doc. i/d : 0109/6
Ref. : 090028
For example, if the min. and max. expected flow velocities are 5m/s and 20m/s respectively with a transducer
separation of 1000mm, then the max. TOF = 200 and then min. TOF = 50. Consequently the ideal
DATA RATE
is ms. Selecting a
DATA RATE
of 0.5ms would be unacceptable because the max.
TOF/DATA RATE
= 400
which is >255. Selecting a
DATA RATE
of 2ms would not be desirable because the min.
TOF/DATA RATE
=
25 which is <50.
For the above example a Data Rate of 0.5ms limits the min. flow velocity to 1000/(0.5 x 255) =
7.84m/s. A Data Rate of 2ms and greater permits the full range of expected velocities but limits
the available resolution of the measurement.
5 PARAMETERS
Data rate 1.0ms
Auto Ranging
Switching the data to
‘auto’ enables the monitor to select automatically, the appropriate data rate for the flow
being measured.
7.9.7.6. Channel Switch
It is normal to install the transducers so that transducer
‘A’ is the upstream (Lead) detector. Should the
installation have been made so that transducer
‘B’ is the upstream detector, this can be accommodated by
setting the channel switch from
‘A’ to ‘B’ using the
and
keys.
5 PARAMETERS
Channel switch A
7.9.7.7. Span Factor
This is a factory-set measurement flow scaling factor and should not be altered without due consideration.
5 PARAMETERS
Span factor 1000
7.9.7.8.Set Clock
The signal processor contains a battery-backed real-time clock that enables calibrations to be initiated at set
and specific times and intervals.
This section enables the clock to be set.
5 PARAMETERS
Set clock
Enter
5 Set clock
Year 2008
Scroll years using
Enter