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Step 6
Enter the rate timebase
Select ‘t-bASE’ from the main menu
and press P to show the current setting.
In this example the rate display is
required in litres per hour. Using the Up
or Down button scroll through the three
options and select ‘tb-3600’ which will
multiply the rate display by 3600.
Return to the ‘t-bASE’ prompt in the
main menu by pressing E.
Step 7
Adjust the rate filter
The rate display filter parameters
should be adjusted experimentally after
installation to provide a stable rate
display with an acceptable step
response.
During commissioning it is recommend
that initially the second digit of the rate
parameters is set to 0 (step response
off) and the first digit (amount of
filtering) is adjusted to provide
acceptable rate display stability. The
second digit should them be increased
until acceptable rate display stability is
once again achieved.
To adjust the filter parameters select
‘FILtEr’ from the main menu and press
P to reveal the current setting. The first
digit will be flashing and may be
adjusted using the Up or Down button.
The P button will transfer control to the
second digit. When both are set as
required, return to the ‘FILtEr’ prompt in
the main menu by pressing E.
Note:
While adjusting the filter, the rate is
shown on the lower display so that
stability can be assessed.
Step 8 Enter the total scaling factor
The K factor of the flowmeter in this
example is 1050.0 pulses per litre and
the total display is required in cubic
metres.
There are 1000 litres in a cubic metre
so the BA338C is required to display 1
cubic metre for every 1,050 x 1,000
pulses received. ‘SCALE-t’ should
therefore be set to 1,050,000
Select ‘SCALE-t’ from the main menu
and press P which will reveal the
current setting with one digit flashing.
To position the decimal point, operate
the P push-button to move the flashing
digit to the least significant position.
Pressing the Up and Down buttons
simultaneously will then remove the
decimal point.
Using the Up and Down buttons to
adjust each digit in turn and the P
button to transfer control between
digits, enter 1050000 Finally return to
the 'SCALE-t' prompt in the main menu
by pressing E.
Step 9
Define clip-off
In this example totalisation is to be
inhibited at flow rates below 300 litres
per hour.
Select ‘CLIP-OFF’ from the main menu
and press P which will reveal the clip-
off threshold in litres per hour i.e. the
same units already selected for the rate
display. The most significant digit of
the display will be flashing, indicating
that this digit may be adjusted.
Pressing P five times will move the
flashing digit to the third lease
significant digit.
Using the Up and Down buttons set the
third least significant digit to 3 i.e. a
clip-off threshold of 300. Finally
return to the 'CLIP-OFF' prompt in the
main menu by pressing E.
.
Step 10 Turn local reset on
In this example the operator needs to
reset the total display to zero by
pressing the Up and Down buttons
simultaneously. To activate the local
reset function select ‘LOC.rSEt’ from
the main menu and press P to display
the current setting. Pressing the Up or
Down button will toggle the display
between ‘On’ and ‘OFF’. Select ‘On’
and press E to return to the ‘LOCrSEt’
prompt in the main menu.
