User Guide

Rateofowandtotalowmaybeshownoneitherthe6or
8 digit displays. If only one variable is required, the lower
six digit display may be disabled.
8 DIGITS
Total flow display
6 DIGIT
Rate of flow display
Alarm status annunciators
Flow symbol ‘rotates’ when
pulse input frequency exceeds 2Hz
Total and rate displays
may be reversed
Lower display may be
disabled
Fig 6 Rate Totaliser display
Thetotaldisplaymayberesettozerobyoperatingtwoofthe
Rate Totaliser’s push buttons, or remotely by connecting
the instruments external reset terminals together for more
than one second.
The Rate Totaliser also maintains a protected Grand Total
whichisnotresetwhenthetotaldisplayiszeroed.Both
the total display and the grand total are retained when the
Rate Totaliser is not powered.
4. Rate Totaliser Conguration
Allmodelsareconguredandcalibratedusingacommon
intuitive menu structured in the same way as all BEKA
instruments. The menu is accessed via the four instrument
pushbuttonsandcanbeprotectedbyauserdenedfour
digit access code. The calibration structure of all single
input Rate Totalisers is shown in Fig 7. This allows a Rate
Totaliser to be congured and calibrated on-site without
the need for external test equipment.
The conguration menu uses English language names
to describe functions and variables such as code and
debounce. When the function name has more than eight
characters a simple abbreviation is used such as di5p-1
(Display1)andt-re5et(Totalreset).InthisApplication
Guide these function and variable names are shown in a
seven segment font, exactly as they appear on the Rate
Totaliser’s display.
BEKA rate Totalisers are easy to calibrate as there are
only four basic variables to adjust.
Flowmeter K-factor factor
Total scale factor 5cale t
Rate scale factor 5cale r
Timebase t-ba5e
Therstthreevariables,factor, 5cale t and 5cale r divide
thenumberofinputpulsesfromtheowmetertoconvertthem
to meaningful engineering units, such as gallons or litres. As
showninFig7theyarearrangedsothatthetotalowand
therateofowcanbeshownindifferentengineeringunits.
Each variable is adjustable between 0.0001 and 99999 and
is described separately in the following sections.
Pulse input
÷
Flowmeter K factor FACtor
Dividing factor usually adjusted
to equal flowmeter K-factor.
Adjustable between
0.0001 and 99999
Note: When the 16
segment lineariser Lin is
selected in the Function menu
up to 16 values of FACtor
may be entered each starting
at a specified pulse frequency
÷
Rate scale factor 5CALE . r
Dividing factor to convert pulse
output from FACtor into the
required units for the rate display
Adjustable between
0.0001 and 99999
X
Timebase t-bA5E
÷
Total scale factor 5CALE . t
Dividing factor to convert pulse
output from FACtor into the
required units for the total display
Adjustable between
0.0001 and 99999
Total display
Grand Total 8 high & 8 low digits
1 for rate per second
60 for rate per minute
3,600 for rate per hour
Rate display
888888
88888888
88888888 88888888
Fig7SingleinputRateTotaliserCongurationstructure
4.1 Flowmeter K-factor
Each output pulse from a owmeter or ow transducer
representsadenedowvolumethathaspassedthrough
theowmeter.Formostowmetersthisissmallcompared
withthetotalowvolume thatis tobe measured. The
performance of owmeters and ow transducers is
therefore dened by the number of output pulses  they
produceforeachunitofowvolumepassingthroughthem
e.g.200pulsespergallonofow.Thisisknownasthe
K-factorofthemeterortransducer.Mostowmetersand
transducersaresuppliedwithatestcerticateshowingthe
averageK-factoroverarangeofowrates.
To convert the pulse output from a owmeter or ow
transducer into engineering units, the number of output
pulsesmustbedividedbytheK-factoroftheowmeteror
owtransducer.
9