BEKA BA334D Manual Download Page 18

Page: 18 / 43

initially the second digit is set to 0 (off) and the
first digit is adjusted to provide acceptable rate
display stability. The second digit should then
be increased until the selected step size is
greater than the noise on the display signal, at
which setting the rate display will again
become stable. These will be the optimum
filter parameters for acceptable rate display
stability and a fast response to a large rate
signal change.

To check or change the filter select 'FILtEr'
from the main menu and press P to reveal the
current settings. Pressing the Up or Down
button will change the flashing digit and P will
transfer control to the second digit. While
making adjustments the filtered rate display is
shown on the lower display so that stability can
be assessed. When set as required, press the
E button to enter the revised parameters and
return to the main menu.

6.11 Total scale factor: ‘SCALE-t’

This factor defines the arithmetic relationship
between the number of input pulses and the
total display. SCALE-t is a dividing factor that
may be adjusted between 0.001 and
99999999. See Fig 8.

When used with a flowmeter  SCALE-t should
be set to the K-factor of the flowmeter  i.e. the
number of pulses the flowmeter produces for a
unit of flow.    If the BA334D total display is
required in units different from those in which
the flowmeter K factor is specified, a
conversion factor will be required.

e.g. If the flowmeter has a K factor of 45.6
pulses per litre and the BA334D total display is
required in units of 1,000 gallons, then
SCALE-t should be set to number of pulses
produced by the flowmeter per 1,000 gallons:

45.6 x 4.54609 x 1000

207,301.7 pulses per 1000 gallons

.
(there are 4.54609 litres in a UK gallon)

To check or change the total scale factor select
'SCALE-t' from the main menu and press P to
reveal the existing setting, one digit will be
flashing. The value of the flashing digit can be
changed by pressing the Up or Down buttons.
When this digit is correct pressing P will
transfer control to the next digit.

To position the decimal point in the scaling
factor, move the flashing digit to the left hand

side of the required decimal point position and
simultaneously press the Up and Down
buttons.

When the required total scale factor has been
entered, press E to store the number and
return to the main menu.

6.12 Clip-off: ‘CLIP-OFF’

To prevent totalisation of very low flow rates
that over long periods may result in significant
totalisation errors, the BA334D may be
programmed to stop totalising when the flow
rate falls below an adjustable threshold.

To check or change the clip-off threshold select
'CLIP-OFF' from the main menu and press P
which will reveal the current setting. The
threshold is shown in the units already selected
for the flow rate display. One digit will be
flashing. The value of the flashing digit may be
changed by pressing the Up or Down buttons.
When this digit is correct pressing P will
transfer control to the next digit. When clip-off
is set as required, press the E button to enter
the revised figure and return to the main
programme menu.

If the flow rate falls below the entered
threshold, the rate display will show zero flow,
totalisation will stop and the HOLD annunciator
will be activated. The flow indicator will rotate
for 2 seconds each time an input pulse is
received i.e. at input frequencies above
0.5Hz it will appear to rotate continuously.

Note:

When the rate scale factor SCALE-r, the

timebase t-bASE, or the position of the rate
display decimal point are changed, clip-off will
automatically be reset to zero. If required, a
new clip-off threshold may then be entered.

6.13 Local reset of total display:
‘LOC. rSEt’

When activated this function enables the
operator to reset the BA334D total display to
zero in the display mode by operating the Up
and Down push-buttons simultaneously for
more than two seconds. To check the status
of the local reset function select 'LOC.rSEt'
from the menu and press P which will reveal if
the function is 'On' or 'OFF'. If necessary
press the Up or Down button to change the
setting, followed by the E button to return to the
main menu.