BEKA BA334E Application Manual
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2. Selecting a model
2.1
Mounting
2.1.1 Field mounting
2.1.2 Panel mounting
2.2
Location
2.2.1 General purpose applications
2.2.2 Explosive atmosphere applications
2.3
Two input models
2.4
Operating temperature
3. Rate Totaliser function
4. Rate Totaliser configuration
4.1
Flowmeter K-factor
4.2
Total scale factor
4.3
Rate scale factor
4.3.1 Resolution
4.4
Timebase
5. Linearisation
6. Pulse output
7. Optional 4/20mA output
8. Optional dual alarm outputs
9. Slide-in scale card
10. Configuration examples
11. Additional information
Externally powered pulse input Rate Totalisers
1. Introduction
This Application Guide is intended to aid the selection
of the most suitable pulse input Rate Totaliser from the
extensive range of models manufactured by BEKA
associates. The guide also contains flow measurement
background information and configuration examples.
This guide does not contain detailed system design or step-
by-step configuration information which are contained in
the instruction manual for each model. Detailed installation
and certification information for use in hazardous areas
is also contained in the instruction manual for each
model which can be viewed on the BEKA website at
www.beka.co.uk
Each output pulse from a flowmeter or flow transducer
represents a defined volume that has passed through the
flowmeter. The total number of pulses therefore represents
the total volume and the pulse frequency represents the
rate of flow passing through the flowmeter. All BEKA
pulse input Rate Totalisers have similar functions and are
able to calculate and display the total flow and the rate of
flow of most pulse output flowmeters.
The BEKA Rate Totaliser range includes field and panel
mounting models for general purpose applications and for
use in gas and dust hazardous areas. All models can be
supplied with a wide range of factory fitted options including
display backlights, alarm outputs and isolated pulse and
current outputs for retransmission applications. Some
models have two pulse inputs enabling the instrument to
calculate and display the sum or difference of the total flow
and rate of flow passing through two flowmeters.
All models are configured and calibrated via four push
buttons using a common configuration menu. Although
easy to configure on-site without the need for test
equipment, Rate Totalisers can be supplied configured
and ready for installation with a printed slide-in scale card
showing customer specified information for no additional
charge.
BEKA also manufacture loop powered 4/20mA Rate
Totalisers which have similar functions and are described
in a separate Application Guide.
APPLICATION GUIDE AG334
Externally powered pulse input Rate Totalisers
For models with an 'E' or 'G' suffix
associates
141 x 212mm
IP66
Field
GRP
141 x 212mm
IP66
Enclosure
material, size
and IP rating
Model
BA334E
BA334G
Some shown with optional
backlight
Number of M20 cable entries
Separate terminal compartment
Yes
Display
Primary: 8 digits 18mm high Secondary: 6 digits 12mm high
Number of inputs
1
Options - must be specified
when indicator is ordered
Backlight
Alarms
4/20mA output
Pulse output
Included
Included
Included
Included
Yes
Yes
Included
Yes
BA384E
No
Yes
No
3
2
3
2
2
Included
Included
Included
Included
Field
GRP
122 x 120mm
IP66
Field
GRP
122 x 120mm
IP66
BA384G
Yes
Yes
Included
Yes
Certification
Europe ATEX
Gas
Dust
Group II
Category 1GD
Ex ia IIC T5 Ga
-40°C ≤ Ta ≤ +70°C
Ex ia IIIC T80°C Da
-40°C ≤ Ta ≤ +60°C
Group II Category 1G
Ex ia IIC T5 Ga
-40°C ≤ Ta ≤ +70°C
N/A
Group II Category 1G
Ex ia IIC T5 Ga
-40°C ≤ Ta ≤ +70°C
Group II Category 1D
Ex ia IIIC T80°C Da
-40°C ≤ Ta ≤ +60°C
Group II Category 1G
Ex ia IIC T5 Ga
-40°C ≤ Ta ≤ +70°C
N/A
Certification
International IECEx
Gas
Dust
Ex ia IIC T5 Ga
-40°C ≤ Ta ≤ +70°C
Ex ia IIIC T80°C Da
-40°C ≤ Ta ≤ +60°C
Ex ia IIC T5 Ga
-40°C ≤ Ta ≤ +70°C
N/A
Ex ia IIC T5 Ga
-40°C ≤ Ta ≤ +70°C
Ex ia IIIC T80°C Da
-40°C ≤ Ta ≤ +60°C
Ex ia IIC T5 Ga
-40°C ≤ Ta ≤ +70°C
N/A
Certification
Canada cETL
Class I Div 1 Gp A, B, C, D T5
Class II Div 1 Gp E, F, G. Class III Div 1
Class I Zone 0 AEx ia IIC T5 Ga
-40°C ≤ Ta ≤ 70°C
Class I Div 1 Gp A, B, C, D T5
Class II Div 1 Gp E, F, G. Class III Div 1
Ex ia IIC T5 Ga
-40°C ≤ Ta ≤ 70°C
Certification
USA ETL
Primary: 8 digits 18mm high Secondary: 6 digits 12mm high
BA384NG
BA584G
No
2
2
Yes
Yes
Included
Yes
Yes
Yes
Included
Yes
BA334NG
1
Yes
Yes
Included
Yes
Field
GRP
122 x 120mm
IP66
No
2
Field
GRP
122 x 120mm
IP66
BA534G
1
Yes
Yes
Included
Yes
Ex ic codes only refer to
push button contacts
Not Certified
General purpose applications only
Group II Category 3G
Ex nA ic IIC T5 Gc
-40°C ≤ Ta ≤ +60°C
Group II Category 3D
Ex ic tc IIIC T80°C Dc
-40°C ≤ Ta ≤ +60°C
Ex nA ic IIC T5 Gc
-40°C ≤ Ta ≤ +60°C
Ex ic tc IIIC T80°C Dc
-40°C ≤ Ta ≤ +60°C
Class I Zone 2 AEx nA ic IIC T5 Gc
Zone 22 AEx ic tc IIIC T80°C Dc
-40°C ≤ Ta ≤ 60°C
Ex nA ic IIC T5 Gc
Ex n IIC T5 Gc
Ex ic tc IIIC T80°C Dc
Class III Div 2 Class II Div 2 Gp F, G
-40°C ≤ Ta ≤ 60°C
Table 1 Field mounting rate totalisers
96 x 48 mm
Panel
Noryl
144 x 72 mm
Enclosure
material & size
Model
BA337E
BA338E
Some shown with optional
backlight
Protection
Display
Primary: 8 digits 18mm high
Secondary: 6 digits 12mm high
Primary:
8 digits 9mm high
Secondary:
6 digits 6mm high
Primary:
8 digits 9mm high
Secondary:
6 digits 6mm high
Number of inputs
1
1
Options - must be specified
when indicator is ordered
Backlight
Alarms
4/20mA output
Yes
#
Yes]
Yes
Yes
Yes
Yes
BA388E
2
Front IP66, rear IP20
Yes
Yes
Yes
Rugged panel
316 stainless steel
105 x 60 mm
BA337E-SS
Yes
Yes
Yes
Certification
Europe ATEX
Gas
Dust
Group II Category 1G
Ex ia IIC T5 Ga -40°C ≤ Ta ≤ +70°C
N/A
Group II Category 1G
Ex ia IIC T5 Ga
-40°C ≤ Ta ≤ +60°C
Group II Category 1D
Ex ia IIIC T80°C Da
-40°C ≤ Ta ≤ +60°C *
Certification
International IECEx
Gas
Dust
Ex ia IIC T5 Ga -40°C ≤ Ta ≤ +70°C
N/A
Ex ia IIC T5 Ga
-40°C ≤ Ta ≤ +60°C
Ex ia IIIC T80°C Da
-40°C ≤ Ta ≤ +60°C *
Class I Div 1 Gp A, B, C, D T5
Class II Div 1 Gp E, F, G. Class III Div 1
Class I Zone 0 AEx ia IIC T5 Ga
-40°C ≤ Ta ≤ 70°C
Class I Div 1 Gp A, B, C, D T5
Class II Div 1 Gp E, F, G. Class III Div 1
Ex ia IIC T5 Ga
-40°C ≤ Ta ≤ 70°C
Certification
Canada cETL
Zone 20 AEx ia IIIC
T80°C Da
-40°C ≤ Ta ≤ 60°C *
Ex ia IIIC T80°C Da
-40°C ≤ Ta ≤ 60°C *
Certification
USA ETL
Pulse output
Yes
Included
Included
Yes
#]
* May be installed in an Ex e, Ex p, Ex n or Ex t panel enclosure without invalidating enclosure certification.
316 stainless steel
105 x 60 mm
Panel
Noryl
96 x 48 mm
Rugged panel
316 stainless steel
105 x 60 mm
Primary:
8 digits 9mm high
Secondary:
6 digits 6mm high
Primary:
8 digits 9mm high
Secondary:
6 digits 6mm high
Primary:
8 digits 9mm high
Secondary:
6 digits 6mm high
Primary: 8 digits 18mm high
Secondary: 6 digits 12mm high
BA537E
BA588E
1
2
Yes
Yes
Yes
Yes
Yes
Yes
BA337NE
1
Yes
Yes
Yes
Front IP66, rear IP20
Front IP66, rear IP20
Panel
Noryl
144 x 72 mm
BA538E
Yes
Yes
Yes
Ex ic codes only refer to
push button contacts
Group II Category 3G
Ex nA ic IIC T5 Gc
-40°C ≤ Ta ≤ +60°C
Group II Category 3D
Ex ic tc IIIC T80°C Dc
-40°C ≤ Ta ≤ +60°C
Ex nA ic IIC T5 Gc
-40°C ≤ Ta ≤ +60°C
Ex ic tc IIIC T80°C Dc IP66
-40°C ≤ Ta ≤ +60°C
Class I Zone 2
AEx nA ic IIC T5 Gc
Zone 22
AEx ic tc IIIC T80°C Dc
-40°C ≤ Ta ≤ 60°C
Ex nA ic IIC T5 Gc
Ex n IIC T5 Gc
-40°C ≤ Ta ≤ 60°C
BA537E-SS
Yes
Yes
Yes
1
Yes
Included
Yes
Included
Yes
Not Certified
General purpose applications only
#]
#]
#]
# Only one may be fitted Table 2 Panel mounting rate totalisers
2. Selecting a model
When selecting a model the following requirements should
be considered:
Mounting
Field or panel
Location
Safe area
Gas Hazardous area
Zone 0, 1 or 2
Type of protection
Certification authority
Dust hazardous area
Zone 20, 21 or 22
Type of protection
Certification authority
Number of inputs
1 or 2 flowmeter inputs
Options
Display backlight
Dual alarm outputs
Pulse output
4/20mA output
To simplify selection Table 1 summarises the specifications
of all the field mounting Rate Totalisers and Table 2
contains similar information for the panel mounting
models. Detailed specifications, datasheets, instruction
manuals and third party safety and ingress certificates
for each model are available from the BEKA website
www.beka.co.uk.
2.1 Mounting
The BEKA range of pulse input Rate Totalisers includes
models for field and panel mounting.
2.1.1 Field mounting
Field mounting Rate Totalisers with a ‘G’ model number
suffix have a robust glass reinforced polyester (GRP)
enclosure with an 8mm thick toughened glass window.
The enclosure has IP66 ingress protection which will not
be degraded by 7J impacts to the GRP case or 4J impacts
to the window at temperatures between -40°C and +70°C.
The enclosure’s ingress and impact protection has been
independently assessed by a third party UKAS accredited
test house. The resulting test certificate is shown on the
BEKA website.
The enclosure material is carbon loaded to prevent the
accumulation of static charges. The thermoset GRP is
very strong and will not corrode or degrade when used
for Rate Totaliser installations in marine and waste water
environments. For installations in hazardous areas, GRP
overcomes the restrictions limiting the use of aluminium in
potentially explosive atmospheres.
Field mounting instruments with a ‘G’ model number suffix
have two M20 x 1.5 tapped cable entries. To maintain
the integrity of the Rate Totaliser enclosure both cable
entries should be fitted with impact resistant M20 x 1.5
IP66 glands, conduit entries or blanking plugs.
The instrument’s units of measurement and tag information
can be marked onto a slide-in scale card clearly visible
above and below the display. Although easy to configure
on-site, Rate Totalisers can be supplied configured and
calibrated with this scale card printed with customer
specified units of measurement for no additional charge.
A 316 stainless steel legend plate which can be supplied
laser engraved with customer specified information is
available as an option.
Field mounting Rate Totalisers are surface mounting, but
can be be pipe or panel mounted using one of the BEKA
accessory kits.
BA393G 316 stainless steel kit, attaches instrument
to any vertical or horizontal pipe with outside
diameter between 40 and 73mm.
BA394G 316 stainless steel panel mounting kit
secures field mounting instrument into a
panel aperture, but does not seal panel
aperture.
BA494G GRP panel mounting kit secures field
mounting instrument into a panel aperture
and provides IP66 seal between front and
rear of the panel. Not certified for field
mounting instruments with an ‘NG’ suffix.
6
In addition to the ‘G’ suffix Intrinsically safe field mounting
models, ‘E’ suffix intrinsically safe Rate Totalisers are
also available. The ‘E’ suffix models have a separate
field terminal enclosure and three tapped M20 x 1.5 cable
entries. These models have display backlights, dual
alarms and isolated pulse and 4/20mA outputs.
2.1.2 Panel mounting
Panel mounting Rate Totalisers are available in 96 x 48mm
and 144 x 72mm glass loaded Noryl (modified PPE) DIN
enclosures with toughened scratch resistant glass display
windows. The enclosure size depends upon the display
size and the number of pulse inputs. Both enclosures have
IP66 front of panel ingress protection, and when correctly
installed provide an IP66 seal between the instrument
and the instrument panel. The ingress protection of
the enclosures have been independently assessed at
temperatures between -40°C and +70°C by a third party
UKAS accredited test house. The resulting test certificate
is shown on the BEKA website.
The instrument’s units of measurement can be marked onto
a slide-in scale card clearly visible at the right hand side of
the display. The scale card can be fitted without opening
the instrument enclosure or removing the Rate Totaliser
from the instrument panel. Although easy to configure
on-site, Rate Totalisers can be supplied configured with
the scale card printed with customer specified units of
measurement for no additional charge.
For panel mounting applications in marine environments,
or where the front of the instrument is likely to be impacted,
single input rugged models are available in a 316 stainless
steel enclosure. These models, which are identified by
an ‘-SS’ model number suffix, have identical features as
the other models including a slide-in scale card. The
enclosure has IP66 front of panel ingress protection, and
when correctly installed provide an IP66 seal between
the instrument and the instrument panel. The ingress
protection of the enclosure has been independently
assessed at temperatures between -40°C and +70°C by a
third party UKAS accredited test house. The resulting test
certificate is shown on the BEKA website.
Intrinsically safe Rate Totalisers with an ‘-SS’ suffix have
been certified for installation in Ex e and Ex p enclosures
without invalidating the certification of the panel enclosure
in which they are mounted.
For applications in Zone 2 or 22 without the need for Zener
barriers or galvanic isolators, the BA337NE Rate Totaliser
has Ex nA non-sparking and Ex tc dust ignition protection
by enclosure. Please see BEKA Application Guide AG310
for more information on how to install this Rate Totaliser.
The rear of panel ingress protection of all 96 x 48mm and
105 x 60mm rugged stainless steel Rate Totalisers can
be increased to IP66 with a BA495 rear cover sealing
kit. Manufactured from 316 stainless steel the cover
incorporates two M20 entries for cable glands, allowing
these Rate Totaliser s to be installed in open panels.
2.2 Location
Having decided how the Rate Totaliser is to be mounted,
the location of the installation will help to determine the
required model.
2.2.1 General purpose application
If the Rate Totaliser is to be installed in an area which does
not have a flammable gas or combustible dust hazard, one
of the following general purpose Rate Totaliser should be
selected.
Field mounting see Table 1
BA534G
1 input
BA538G
2 input
Panel mounting models are available in two alternative DIN
enclosure sizes plus a rugged impact resistant instrument
in a 316 stainless steel enclosure.
Panel mounting see Table 2
BA537E
1 input 96 x 48mm
BA538E
1 input 144 x 72mm
BA537E-SS 1 input Rugged 105 x 60mm
BA588E
2 input 144 x 72mm
2.2.2 Explosive atmosphere applications
To select a Rate Totaliser for a hazardous area installation,
the Zone or Division in which it is to be installed and
the hazard must be known, together with the required
certification authority i.e. IECEx, ATEX or ETL.
The range includes intrinsically safe Ex ia models for
installation in most gas and dust Zones. For installations
in Zone 2 or 22 without the need for Zener barriers or
galvanic isolators, models with non-sparking Ex nA
certification for gas hazards and dust ignition protection by
enclosure Ex tc are included.
Field mounting see Table 1
BA334E
1 input
1G
Ex ia
Separate terminal
compartment.
BA334G
1 input
1GD
Ex ia
BA384E
2 input
1G
Ex ia
Separate terminal
compartment.
BA384G
2 input
1GD
Ex ia
BA334NG
1 input
3GD
Ex nA and Ex tc
BA384NG
2 input
3GD
Ex nA and Ex tc
Panel mounting see Table 2
BA337E
1 input
96 x 48mm
1G Ex ia
BA338E
1 input
144 x 72mm
1G Ex ia
BA337E-SS 1 input
Rugged 105 x 60mm 1GD Ex ia
BA388E
2 input
144 x 72mm
1G Ex ia
BA337NE
1 input
105 x 60mm
3GD Ex nA
and Ex tc
7
When selecting a Rate Totaliser for installation in a
hazardous area, the instrument’s hazardous area certificate
should be consulted to ensure that the instrument has
approval for the required area, hazard and temperature
range.
2.3 Two input models
The two input Rate Totalisers are primarily intended for
use with two flowmeters. Each Rate Totaliser input is
individually configurable and the instrument can display
either input, or the sum or difference of the two flow rates
and totals.
The two input models enable the total flow and flow rate
from two sources to be calculated and displayed. If it
is required to add more than two flow sources, multiple
Rate Totalisers can be linked using the instrument’s
synchronous pulse output.
2.4 Operating temperature
All the field and panel mounting Rate Totalisers except
models with an ‘E-SS’, ‘NG’ and ‘NE’ suffix have a specified
operating temperature of -40°C to +70°C. Between these
temperatures the Rate Totalisers will function normally,
however at temperatures below -20°C the display digits
will gradually change more slowly and contrast will be
reduced. At some temperature below -20° the display will
stop functioning, but totalisation will continue normally and
the instrument will not be damaged.
Models with an ‘E-SS’, ‘NG’ and ‘NE’ suffix have a maximum
certification temperature of +60°C but performance is the
same as the other models at low temperatures.
3. Rate Totaliser function
All BEKA externally powered pulse input Rate Totalisers
have similar functions, although the number of inputs and
the output options may differ. Fig 1 shows a simplified
block diagram of a one input instrument.
All models can accept pulses from a wide variety of
flowmeter transducers or outputs. To enable a Rate
Totaliser to count pulses from transducers such as a
switch contact, open collector transistor or a two wire
proximity detector, the transducer has to be powered
which is achieved by fitting an external link between two of
the Rate Totaliser’s field terminals.
1
2
3
4
5
6
RS1
RS2
Power
supply
A4
A3
A2
A1
Alarm
2
Alarm
1
+
+
Optional
isolated
alarms
C4
C3
C2
C1
+
Optional
isolated
4/20mA
output
Optional
backlight
internally
powered
Processor
Display
+
+
+
Link to
energise
input
Input
Pulse low
Pulse high
Magnetic pick-off
Proximity detector
Switch contact
Open collector
Isolated pulse output is optional on 96x48mm panel mounting models
External
reset
P2
P1
+
Earth
Isolated
pulse
output
Fig 1 Simplified diagram of single input Rate Totaliser
Rate Totalisers can calculate and display the rate of flow
and the total flow from most pulse output flowmeters
including non-linear flowmeters such as a turbine meter
operating over a wide range of flows. All models include
a sixteen segment lineariser which can be configured
to minimise non-linearity errors. Rate Totalisers with
two inputs have separate configuration functions and a
separate lineariser for each input.
All the Rate Totaliser models have separate rate and total
displays as shown in Fig 2 with independent calibration
allowing the rate of flow and the total flow to be displayed
in different units of measurement. e.g. rate of flow could
be shown in litres per hour and the total flow could be in
cubic metres. The display digit size depends upon the
model as shown below.
Display size
6 digits
8 digits
Field mounting
All models
12mm
18mm
Panel mounting
96 x 48mm
6mm
9mm
144 x 72mm
12mm
18mm
Rugged 105 x 60mm
6mm
9mm
8
Rate of flow and total flow 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 2 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 Configuration
All models are configured 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 defined four
digit access code. The calibration structure of all single
input Rate Totalisers is shown in Fig 3. This allows a Rate
Totaliser to be configured and calibrated on-site without
the need for external test equipment.
The configuration 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 first three variables, factor, 5cale t and 5cale r divide
the number of input pulses from the flowmeter to convert them
to meaningful engineering units, such as gallons or litres. As
shown in Fig 3 they are arranged so that the total flow and
the rate of flow 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 3 Single input Rate Totaliser Configuration structure
4.1 Flowmeter K-factor
Each output pulse from a flowmeter or flow transducer
represents a defined flow volume that has passed through
the flowmeter. For most flowmeters this is small compared
with the total flow volume that is to be measured. The
performance of flowmeters and flow transducers is
therefore defined by the number of output pulses they
produce for each unit of flow volume passing through them
e.g. 200 pulses per gallon of flow. This is known as the
K-factor of the meter or transducer. Most flowmeters and
transducers are supplied with a test certificate showing the
average K-factor over a range of flow rates.
To convert the pulse output from a flowmeter or flow
transducer into engineering units, the number of output
pulses must be divided by the K-factor of the flowmeter or
flow transducer.
9
4.2 Total Scale Factor 5cale . t
As shown in the previous section the Rate Totaliser
function factor is used to convert the number of input
pulses received into engineering units such as litres or
gallons.
If the Rate Totaliser’s total display is required in the
engineering units produced by factor no further scaling
is required. However, to enable the total display to
be in different engineering units, or in multiples of the
engineering units produced by factor such as thousand
of litres or gallons, an additional scaling factor 5CALE . t is
included.
5CALE . t is a dividing factor adjustable between 0.0001
and 99999 that divides the output of the factor function to
produce the total display in the required engineering units.
Fig 5 illustrates how 5CALE . t can be used to extend the
example shown in Fig 4 to produce a total display in m³.
Each pulse output from factor represent one litre of total
flow. There are 1,000 litres in a cubic metre, therefore the
output from factor requires dividing by 1000 to convert it
to cubic metres m³.
1 pulse per litre of flow
70 pulses per
litre of flow
Flowmeter with
K-factor of 70
÷
Flowmeter K factor factor
Set to 70
÷
Rate scale factor 5cale . r
Set to 4.5461
÷
Total scale factor 5cale . t
Set to 1000
x
Timbase t-ba5e
Set to 60 for rate per minute
Total Display
Cubic metres of flow m³
Rate Display
Gallons of flow per minute
1 pulse per
gallon of flow
1 pulse per cubic
meter m³ of flow
Fig 5 5cale . t set to 1000 to produce total flow
display in cubic metres m³
This can be illustrated with a simple example. To calculate
the total flow in engineering units measured by a flowmeter
having a K-factor of 70 pulses per litre after it has output
1075 pulses.
Number of output pulses = 1075 = 15.36 litres
Flowmeter K-factor 70
All BEKA pulse input Rate Totalisers achieve this
conversion using a configurable dividing constant called
factor which can be adjusted between 0.0001 and 99999
as shown in Fig 3.
For the flowmeter in this example having a K-factor of 70
pulses per litre, the dividing constant factor in the Rate
Totaliser should be set to 70. After the Rate Totaliser
has received 70 pulses from the flowmeter it will transfer
one pulse, representing 1 litre of flow, to the following Rate
Totaliser adjustable functions Scale Factor 5cale r and
the Total Scale Factor 5cale t as shown in Fig 4.
Unless a resolution greater than one K-factor unit of
measurement is required, i.e. 1 litre in the above example,
for most applications factor should be set to the K-factor
of the flowmeter. Section 10.1 contains additional
information about Rate Totaliser resolution.
1 pulse per litre of flow
70 pulses per
litre of flow
Flowmeter with
K-factor of 70
÷
Flowmeter K factor factor
Set to 70
÷
Rate scale factor 5cale . r
Set to 4.5461
÷
Total scale factor 5cale . t
Set to 1000
x
Timbase t-ba5e
Set to 60 for rate per minute
Total Display
Cubic metres of flow m³
Rate Display
Gallons of flow per minute
1 pulse per
gallon of flow
1 pulse per cubic
meter of flow
Fig 4 factor set to flowmeter K-factor
10
1 pulse per litre of flow
70 pulses per
litre of flow
Flowmeter with
K-factor of 70
÷
Flowmeter K factor factor
Set to 70
÷
Rate scale factor 5cale . r
Set to 4.5461
÷
Total scale factor 5cale . t
Set to 1000
x
Timbase t-ba5e
Set to 60 for rate per minute
Total Display
Cubic metres of flow m³
Rate Display
Gallons of flow per minute
1 pulse per
gallon of flow
1 pulse per cubic
meter of flow
Fig 6 5cale . r and t-ba5e set to provide a Rate Display
in Gallons / minute
4.4 Timebase: t-bA5E
As described in the previous section, the rate scale factor
5cale . r defines the engineering units of the rate display.
The Rate Totaliser can display rate of flow per second, per
minute or per hour.
The Rate Totaliser timebase t-ba5e enables the output
from 5cale . r to be multiplied by 1, 60 or 3,600 to produce
a rate display per second, per minute or per hour as shown
below:
t-ba5e menu
options
tb-1
x 1 for flow / second
tb-60
x 60 for flow / minute
tb-3600
x 3600 for flow / hour
For this example the rate display is required in gallons per
minute, therefore t-ba5e is set to tb-60 as shown in Fig 6.
4.3 Rate scale factor 5cale . r
Function 5CALE . r is similar to 5cale t described in the
previous section. As shown in section 4.1 the Rate
Totaliser function factor is used to convert the number of
input pulses received from the flowmeter into engineering
units such as litres or gallons.
If the Rate Totaliser’s rate display is required in the
engineering units produced by factor no further scaling
is required. However, to enable the rate display to be
in different engineering units, or in multiples of the
engineering units produced by factor such as thousand
of litres or gallons, an additional scaling factor 5CALE . r is
included.
Functions 5cale . r and 5cale . t receive their inputs from
factor. Both are independently adjustable which enables
the Rate Totaliser to have rate and total displays with
different units of measurement.
5cale . r is a dividing factor adjustable between 0.0001
and 99999 that enables rate of flow to be displayed in the
required engineering units. It is used in conjunction with
the Rate Totalisers timebase t-ba5e which determines
whether the flow rate is displayed per second, per minute
or per hour.
Continuing the example shown in Fig 4 and assuming
that the flow rate display is required in gallons per minute.
Fig 6 illustrates how 5cale . r is set to produce a rate
display in gallons. Each pulse output from the factor
function represent one litre of total flow. There are 4.5461
litres in an imperial gallon, therefore the output from factor
requires dividing by 4.5461 to convert it to imperial gallons.
This is achieved by setting 5cale . r to 4.5461.
4.3.1 Resolution
The output from factor will determine the resolution of
the Rate Totaliser. If increments of flow smaller than
one K-factor unit of measurement are significant, factor
should be reduced.
The effect of reducing factor for a flowmeter having a
K-factor of 200 pulses per litre are shown below.
Factor
Instrument resolution
200
1 litre
20
0.1 litre
2
0.01 litre
TOTAL
________
RATE
BA337E
6501
50 . 0
Total and Rate are displayed simultaneously and can
have different units of measurements
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Flowmeters are usually supplied with a calibration
certificate specifying their average K-factor and the flow
range over which it applies. For use over extended flow
ranges and for non-linear flowmeters, multiple K-factors
will be specified each at a different flow rate. For these
devices the calibration certificate is likely to contain a table
similar to the one shown below.
Flow Rate
Litres/min
K-factor
Pulses/litre
5
200
10
230
15
239
20
242
Table 3 Typical flowmeter calibration certificate
To minimise display errors resulting from flowmeter
non-linearity, all BEKA Rate Totalisers incorporate a 16
segment straight line lineariser which when correctly
configured will compensate for the flowmeter non-linearity.
When the Rate Totaliser’s lineariser is enabled up to
16 values of the flowmeter’s K-factor may be entered in
the l-factor function, each at a specified input pulse
frequency pul5e fre.
The output frequency of the flowmeter, which is required for
calibrating the Rate Totaliser lineariser, can be calculated
from the information in the flowmeter calibration certificate.
Output frequency Hz = (Flow rate per min) x (K-factor)
60
Or if the flow rate is specified per second.
Output frequency Hz = (Flow rate per second) x (K-factor)
Flow Rate
Litres/min
K-factor
Pulses/litre
Output
frequency
Hz
0
0
0
5
200
16.666
10
230
38.333
15
239
59.750
20
242
80.666
Table 4 Calculated lineariser calibration information
6 Pulse output
All field mounting BEKA Rate Totalisers and the 144 x 72mm
panel mounting models have an optically isolated open
collector pulse output. This pulse output is available as
a factory fitted option for the smaller 96 x 48mm and the
rugged 105 x 60mm panel mounting models.
The output pulse may be a synchronous duplicate of the input
pulse for re-transmission applications, or it may be derived
from incrementation of the least significant digit of the total
display, irrespective of the decimal point position. When
derived from the total display the output pulse frequency
may be divided and the output pulse width defined.
Selecting dirECt in the pulse output configuration menu
produces a synchronous duplicate of the Rate Totaliser
input pulse at frequencies up to 5kHz.
When 5CALEd is selected in the pulse output configuration
menu, the pulse output is derived from the incrementation
of the least significant digit of the total display, irrespective
of the position of the displayed decimal point. When
5CALEd is selected the Rate Totalisers pulse output
frequency may be divided by:
1
10
100
1000
10000
and the pulse output width (duration) may be selected
from eleven options:
0 . 1 ms
0 . 5 ms
1 ms
2 . 5 ms
5 ms
10 ms
25 ms
50 ms
100 ms
250 ms
500 ms
If configured such that the output pulse frequency with
the specified pulse width can not be output in real time,
the number of pulses will be stored and transmitted at
the maximum possible speed, but will not be stored if
the total display is reset to zero or the Rate Totaliser is
disconnected or switched off.
To prevent misleading or dangerous pulse outputs after
any changes are made to the Rate Totaliser configuration,
the pulse output must be manually re-enabled before it will
function.
The pulse output of a two input Rate Totaliser may be a
synchronous duplicate of either pulse input, or it may be
derived from incrementation of the least significant digit of
the composite total display (input A + input b) irrespective
of which total is being displayed by the instrument.
A pulse output can not be derived from a composite total
display of (input A - input b).
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7. Optional 4/20mA output
All BEKA Rate Totalisers can be supplied with a factory
fitted galvanically isolated 4/20mA current sink output which
can be used for retransmission to other instrumentation.
This output appears as a 4/20mA loop powered transmitter
requiring an external power supply between 5 and 28V.
The output can be configured to represent any part of the
instrument’s rate or total display.
To prevent a misleading or dangerous current output
after any changes to the Rate Totaliser configuration, the
4/20mA output must be manually re-enabled before it will
function.
8. Optional dual Alarm outputs
All BEKA Rate Totalisers can be supplied with factory
fitted dual alarms. Each alarm has a galvanically isolated,
solid state single pole, voltage free output that may be
independently configured as a high or low, rate or total
alarm with a normally open or normally closed output.
Configurable functions for each alarm include the setpoint,
alarm delay and silence time. Hysteresis may be applied
to rate alarms.
When the Rate Totaliser’s power supply is turned off
or disconnected, alarm outputs will open irrespective
of whether normally open or normally closed outputs
have been selected. When designing a system it is
recommended that an open output should be selected for
the alarm condition.
Alarm annunciators on the instrument display indicate the
status of each alarm. If an alarm delay or silence time has
been selected the annunciator will flash during the delay
or silence period.
9. Slide-in scale card
All Rate Totaliser’s, except the ‘E’ suffix field mounting
models, have a slide-in scale card which can be printed
to show the instruments units of measurement. The scale
card is mounted on a flexible strip that is inserted into a slot
at the rear of panel mounting Rate Totalisers and adjacent
to the terminals on field mounting instruments.
New Rate Totalisers can be supplied with a printed scale
card showing requested units of measurement for no
additional charge. If this information is not supplied when
the instrument is ordered a blank card will be fitted which
can easily be marked on-site.
Inserting scale card in panel Rate Totaliser
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This example illustrates a Rate Totaliser with the rate and
total displays having different engineering units. Total flow
is required in m³ with a resolution of 0.1 and the flow rate
in litres per Minute with a resolution of 1.
An output pulse is required for each 0.1m³ of total flow.
The flowmeter has a K-factor of 1 pulse per litre.
Summary
Flowmeter K-factor
1 pulse / litre
Required total display
0.0 m³
Required rate display
0 litres / minute
Pulse output
1 pulse / 0.1 litres of flow
Rate Totaliser Configuration
Flowmeter K-factor
Factor
1
Each output pulse from the flowmeter represents 1 litre
therefore no further conversion is required.
Total display
5cale t
1000
dp total
0 . 0
Display is required in m³, therefore 5cale t is set to 1000
as there are 1000litres in a m³. Total display resolution
of 0.1 m³ is required, hence decimal point is positioned
before the least significant digit.
Rate display
5cale r
1 . 0
dp rate
0
t-ba5e
tb-60
Display is required in litres / minute. Each pulse already
represents 1 litre so no further scaling is required and
5cale r is set to 1.0 Rate display resolution of 1 litre
is required, hence decimal point is positioned after the
least significant display digit where it is not visible.
Selecting a timebase of tb-60 multiplies the rate display
by 60 to show the flow rate per minute.
Pulse output
5ource
5caled
divide
1
The Rate Totaliser outputs a pulse each time the least
significant digit of the total display is incremented. The
least significant digit of the total display represents 0.1
m³ which is the required output pulse resolution,therefore
no further division is required.
10. Configuration examples
This section contains some examples of Rate Totaliser
configurations requested by BEKA customers. Step-by-
step instructions are not included nor are non-calibration
configuration functions.
Example 1
In this example a user required a BEKA Rate Totaliser to
display total flow in Gallons with a resolution of 0.1 and the
flow rate in Gallons per Minute with a resolution of 1.
An output pulse is required for each gallon of total flow.
The flowmeter has a K-factor of 10 pulses per Gallon.
Summary
Flowmeter K-factor
10 pulses / gallon
Required total display
0.0 gallons
Required rate display
0 gallons / minute
Pulse output
1 pulse / 1 gallon of flow
Rate Totaliser Configuration
Flowmeter K-factor
Factor
10 . 0
Converts output from flowmeter into engineering units
gallons.
Total display
5cale t
1 . 0
dp total
0 . 0
Display is required in gallons, therefore 5cale t is set to 1
as Factor has converted pulse input into gallons. Total
display resolution of 0.1 gallons is required, hence decimal
point is positioned before the least significant digit.
Rate display
5cale r
1 . 0
dp rate
0
t-ba5e
tb-3600
Display is required in gallons, therefore 5cale r is set to 1
as Factor has converted pulse input into gallons. Rate
display resolution of 1 gallon is required, hence decimal
point is positioned after least significant display digit
where it is not visible.
Selecting a timebase of tb-60 multiplies the rate display
by 60 to show flow rate per minute.
Pulse output
5ource
5caled
divide
10
The Rate Totaliser outputs a pulse each time the least
significant digit of the total display is incremented. The
least significant digit represents 0.1 gallons so this rate
has to be divided by 10 to produce one output pulse per
gallon of total flow.
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The requirements of this example are identical to those for
example 2 except for the pulse output. In this example an
output pulse is required for each litre of flow. which is the
same as that being produced by the flowmeter.
Pulse output
5ource
direct
The required output pulse from the Rate Totaliser is the
same as pulse output from the flowmeter i.e. 1 pulse per
litre. Selecting direct in the pulse output configuration
menu, results in the output pulse being a synchronous
duplicate of the Rate Totaliser input pulse.
Example 4
This example illustrates how a Rate Totaliser can display
total flow and the rate of flow from a stroke sensor on a
reciprocating pump.
A display of the total oil flow is required in barrels of oil with
a resolution of 0.1. The Rate Totaliser is also required to
display the pump stroke rate in pump strokes per Minute.
An output pulse is required for each barrel of total flow.
Each pulse from the pump represent one stroke which is
equivalent to 0.6247 US Gallons.
Summary
Flowmeter K-factor
1 pulse / 0.6247 USG
Required total display
0.0 Barrels
Required rate display
0 Strokes / minute
Pulse output
1 pulse / Barrel
Rate Totaliser Configuration
Flowmeter K-factor
Factor
1 . 0
Each output pulse from the pump represents 1 stroke
therefore no further conversion is required.
Total display
5cale t
67 . 232
dp total
0 . 0
The display is required in Barrels, therefore 5cale t has
to convert pump strokes to Barrels.
Each pump stroke displaces 0.6247 US Gallons and
there are 42 US Gallons in a barrel.
5Cale t = 42 / 0.6247 = 67.232
Total display resolution of 0.1 barrels is required, hence
decimal point is positioned before the least significant
digit of the display.
Rate display
5cale r
1. 0
dp rate
0
t-ba5e
tb-60
Display is required in pump strokes / minute. Each
pulse already represents 1 pump stroke so no further
scaling is required and 5cale r is set to 1. Rate display
resolution of 1 Stroke is required, hence decimal point
is positioned after least significant display digit where it
is not visible.
Selecting a timebase of tb-60 multiplies the rate display
by 60 to show pump strokes rate per minute.
Pulse output
5ource
5caled
divide
10
The Rate Totaliser outputs a pulse each time the least
significant digit of the total display is incremented. The
least significant digit represents 0.1 barrels so this rate
has to be divided by 10 to produce one output pulse per
barrel of total flow.
15
This example illustrates how a BEKA two input Rate
Totaliser can be used to display the rate of flow and
the total flow of two reciprocating mud pumps and their
composite rates and totals i.e. pump 1 + pump 2. Each
pump has a displacement of 1 litre per stroke and a sensor
outputs one pulse per stroke.
The rate display is required in pump strokes per minute
and the total mud flow is to be displayed in m³ with a
resolution of 0.1 m³. Operating the Rate Totalisers front
panel * or & push button while the instrument is
functioning scrolls the display through pump 1, pump 2 or
the composite output of both pumps, but it does not affect
the instruments performance or output.
A pulse is to be transmitted by the Rate Totaliser for each
0.1 m³ of composite mud pumped i.e. pump 1 + pump 2.
Summary
Pump K-factor
1 pulse / stroke which is
equivalent to 1 litre.
Required total display
0.0 m³
Required rate display
0 strokes / minute
Pulse output
1 pulse / 0.1m³ of composite
total flow.
Rate Totaliser Configuration
K-factor
FACtor-A pump 1
1 . 0
FACtor-b pump 2
1 . 0
Each output pulse from pump 1 and pump 2 represents
1 stroke which is equivalent to 1 litre of flow therefore no
further conversion is required.
Total display
5CALE . t-A
1000
5CALE . t-b
1000
The display is required in m³, therefore 5CALE . t has to
convert litres to m³. Each pump stroke displaces 1 litre
and there are 1000 litres in each m³.
Rate Display
5CALE . r-A
1
5CALE . r-b
1
dP rAtE
0
t-bA5E
tb-60
The rate display is required in strokes per minute. Each
pulse from pumps 1 and 2 represents 1 pump stroke so
no further scaling is required for either input. Therefore
both 5CALE . r-A and 5CALE . r-b are set to 1. Rate display
resolution of 1 stroke is required, hence decimal point is
positioned after the least significant display digit where
it is not visible. Selecting a timebase of tb-60 multiplies
the rate display by 60 to show pump stroke rate per
minute.
Pulse output
5ourCE
5CALEd
diVidE
1
An output pulse is required for each composite 0.1 m³ of
mud pumped. The Rate Totaliser outputs a pulse each
time the least significant digit of the composite total (pulse
input A + pulse input b) is incremented, irrespective of
whether the composite total is being displayed. In this
example the least significant digit of the composite total
represents 0.1m³ so scaling is not require.
However, if an output pulse was required for every 1.0m³
of composite total that was pumped, diVidE would have
to be set to 10 i.e. 10 increments of the least significant
digit (0.1m³ per increment) would occur before an output
pulse was produced.
11. Additional information
If additional information or help is required with Rate
Totaliser configuration, please call one of our sales
engineers who will be pleased to help.
Although Rate Totalisers are easy to configure on-site,
they can be supplied configured to customer specified
requirements with a printed slide-in scale card for no
additional charge.
BEKA associates Ltd.
Old Charlton Road., Hitchin, Herts. SG5 2DA UK Tel: (01462) 438301 Fax: (01462) 453971 e-mail [email protected] www.beka.co.uk
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