Vega VEGABAR 82 User manual

Operating Instructions
Pressure transmitter with ceramic
measuring cell
VEGABAR 82
Slave sensor for electronic di󰀨erential pres-
sure
With SIL qualication
Document ID: 48046

2
Contents
VEGABAR 82 • Slave sensor for electronic dierential pressure
48046-EN-190320
Contents
1 About this document ............................................................................................................... 4
1.1 Function ........................................................................................................................... 4
1.2 Target group..................................................................................................................... 4
1.3 Symbols used................................................................................................................... 4
2 For your safety ......................................................................................................................... 5
2.1 Authorised personnel ....................................................................................................... 5
2.2 Appropriate use................................................................................................................ 5
2.3 Warning about incorrect use............................................................................................. 5
2.4 General safety instructions............................................................................................... 5
2.5 EU conformity................................................................................................................... 6
2.6 SIL qualication according to IEC 61508.......................................................................... 6
2.7 Permissible process conditions........................................................................................ 6
2.8 Installation and operation in the USA and Canada ........................................................... 6
2.9 Environmental instructions ............................................................................................... 7
3 Product description ................................................................................................................. 8
3.1 Conguration.................................................................................................................... 8
3.2 Principle of operation........................................................................................................ 9
3.3 Supplementary cleaning procedures.............................................................................. 14
3.4 Packaging, transport and storage................................................................................... 14
3.5 Accessories and replacement parts ............................................................................... 15
4 Mounting................................................................................................................................. 16
4.1 General instructions ....................................................................................................... 16
4.2 Ventilation and pressure compensation.......................................................................... 17
4.3 Combination Master - Slave ........................................................................................... 19
4.4 Level measurement........................................................................................................ 20
4.5 Dierential pressure measurement ................................................................................ 21
4.6 Interface measurement .................................................................................................. 22
4.7 Density measurement .................................................................................................... 23
4.8 Density-compensated level measurement ..................................................................... 24
4.9 External housing ............................................................................................................ 26
5 Connecting to power supply................................................................................................. 27
5.1 Preparing the connection ............................................................................................... 27
5.2 Connecting..................................................................................................................... 27
5.3 Single chamber housing................................................................................................. 29
5.4 External housing with version IP 68 (25 bar)................................................................... 29
5.5 Connection example ...................................................................................................... 31
6 Functional safety (SIL) .......................................................................................................... 32
6.1 Objective........................................................................................................................ 32
6.2 SIL qualication.............................................................................................................. 32
6.3 Application area ............................................................................................................. 32
6.4 Safety concept of the parameterization .......................................................................... 33
7 Set up with the display and adjustment module ................................................................ 35
7.1 Parameter adjustment .................................................................................................... 35
8 Diagnosis, asset management and service ........................................................................ 49
8.1 Maintenance .................................................................................................................. 49

3
Contents
VEGABAR 82 • Slave sensor for electronic dierential pressure
48046-EN-190320
8.2 Cleaning - hygienic connection with compression nut .................................................... 49
8.3 Rectify faults................................................................................................................... 50
8.4 Exchanging the electronics module................................................................................ 50
8.5 Exchange process module on version IP 68 (25 bar) ..................................................... 51
8.6 How to proceed if a repair is necessary.......................................................................... 52
9 Dismount................................................................................................................................. 53
9.1 Dismounting steps.......................................................................................................... 53
9.2 Disposal ......................................................................................................................... 53
10 Supplement ............................................................................................................................ 54
10.1 Technical data ................................................................................................................ 54
10.2 Calculation of the total deviation..................................................................................... 64
10.3 Practical example........................................................................................................... 65
10.4 Dimensions .................................................................................................................... 67
10.5 Industrial property rights................................................................................................. 77
10.6 Trademark ...................................................................................................................... 77
Safety instructions for Ex areas
Take note of the Ex specic safety instructions for Ex applications.
These instructions are attached as documents to each instrument
with Ex approval and are part of the operating instructions.
Editing status: 2019-03-11

4
1 About this document
VEGABAR 82 • Slave sensor for electronic dierential pressure
48046-EN-190320
1 About this document
1.1 Function
This operating instructions provides all the information you need for
mounting, connection and setup as well as important instructions for
maintenance, fault rectication, the exchange of parts and the safety
of the user. Please read this information before putting the instrument
into operation and keep this manual accessible in the immediate
vicinity of the device.
1.2 Target group
This operating instructions manual is directed to trained personnel.
The contents of this manual must be made available to the qualied
personnel and implemented.
1.3 Symbols used
Document ID
This symbol on the front page of this instruction refers to the Docu-
ment ID. By entering the Document ID on www.vega.com you will
reach the document download.
Information, tip, note
This symbol indicates helpful additional information.
Caution: If this warning is ignored, faults or malfunctions can result.
Warning: If this warning is ignored, injury to persons and/or serious
damage to the instrument can result.
Danger: If this warning is ignored, serious injury to persons and/or
destruction of the instrument can result.
Ex applications
This symbol indicates special instructions for Ex applications.
• List
The dot set in front indicates a list with no implied sequence.
→ Action
This arrow indicates a single action.
1 Sequence of actions
Numbers set in front indicate successive steps in a procedure.
Battery disposal
This symbol indicates special information about the disposal of bat-
teries and accumulators.

5
2 For your safety
VEGABAR 82 • Slave sensor for electronic dierential pressure
48046-EN-190320
2 For your safety
2.1 Authorised personnel
All operations described in this documentation must be carried out
only by trained, qualied personnel authorised by the plant operator.
During work on and with the device, the required personal protective
equipment must always be worn.
2.2 Appropriate use
VEGABAR 82 is a slave sensor for electronic dierential pressure
measurement.
You can nd detailed information about the area of application in
chapter "Product description".
Operational reliability is ensured only if the instrument is properly
used according to the specications in the operating instructions
manual as well as possible supplementary instructions.
2.3 Warning about incorrect use
Inappropriate or incorrect use of this product can give rise to applica-
tion-specic hazards, e.g. vessel overll through incorrect mounting
or adjustment. Damage to property and persons or environmental
contamination can result. Also, the protective characteristics of the
instrument can be impaired.
2.4 General safety instructions
This is a state-of-the-art instrument complying with all prevailing
regulations and directives. The instrument must only be operated in a
technically awless and reliable condition. The operator is responsi-
ble for the trouble-free operation of the instrument. When measuring
aggressive or corrosive media that can cause a dangerous situation
if the instrument malfunctions, the operator has to implement suitable
measures to make sure the instrument is functioning properly.
During the entire duration of use, the user is obliged to determine the
compliance of the necessary occupational safety measures with the
current valid rules and regulations and also take note of new regula-
tions.
The safety instructions in this operating instructions manual, the na-
tional installation standards as well as the valid safety regulations and
accident prevention rules must be observed by the user.
For safety and warranty reasons, any invasive work on the device
beyond that described in the operating instructions manual may be
carried out only by personnel authorised by the manufacturer. Arbi-
trary conversions or modications are explicitly forbidden. For safety
reasons, only the accessory specied by the manufacturer must be
used.
To avoid any danger, the safety approval markings and safety tips on
the device must also be observed and their meaning read in this oper-
ating instructions manual.

6
2 For your safety
VEGABAR 82 • Slave sensor for electronic dierential pressure
48046-EN-190320
2.5 EU conformity
The device fulls the legal requirements of the applicable EU direc-
tives. By axing the CE marking, we conrm the conformity of the
instrument with these directives.
You can nd the EU conformity declaration on our website under
www.vega.com/downloads.
2.6 SILqualicationaccordingtoIEC61508
The Safety Integrity Level (SIL) of an electronic system is used to as-
sess the reliability of integrated safety functions.
For detailed specication of the safety requirements, multiple SIL
levels are specied according to safety standard IEC 61508. You can
nd detailed information in chapter "Functional safety (SIL)" of the
operating instructions.
The instrument meets the specications of IEC 61508: 2010 (Edi-
tion 2). It is qualied for single-channel operation up to SIL2. The
instrument can be used homogeneously redundant up to SIL3 in
multi-channel architecture with HFT 1.
2.7 Permissible process conditions
For safety reasons, the instrument must only be operated within the
permissible process conditions. You can nd detailed information on
the process conditions in chapter "Technical data" as well as on the
type label.
The permissible process pressure range is specied by "MWP"
(Maximum Working Pressure) on the type label, see chapter "Struc-
ture". The MWP takes the element of the measuring cell and process-
ing tting combination with the weakest pressure into consideration
and may applied permanently. The specication refers to a reference
temperature of +20 °C (+68 °F). It also applies when a measuring cell
with a higher measuring range than the permissible pressure range of
the process tting is installed order-related.
In order to prevent damage to the device, the test pressure may only
exceed the specied MWP briey by 1.5 times at reference tempera-
ture. The pressure stage of the process tting as well as the overload
resistance of the measuring cell are taken into consideration here
(see chapter "Technical Data").
In addition, a temperature derating of the process tting, e. g. with
anges, can limit the permissible process pressure range according
to the respective standard.
2.8 Installation and operation in the USA and
Canada
This information is only valid for USA and Canada. Hence the follow-
ing text is only available in the English language.
Installations in the US shall comply with the relevant requirements of
the National Electrical Code (ANSI/NFPA 70).

7
2 For your safety
VEGABAR 82 • Slave sensor for electronic dierential pressure
48046-EN-190320
Installations in Canada shall comply with the relevant requirements of
the Canadian Electrical Code.
2.9 Environmental instructions
Protection of the environment is one of our most important duties.
That is why we have introduced an environment management system
with the goal of continuously improving company environmental pro-
tection. The environment management system is certied according
to DIN EN ISO 14001.
Please help us full this obligation by observing the environmental
instructions in this manual:
• Chapter "Packaging, transport and storage"
• Chapter "Disposal"

8
3 Product description
VEGABAR 82 • Slave sensor for electronic dierential pressure
48046-EN-190320
3 Product description
3.1 Conguration
The scope of delivery encompasses:
• Pressure transmitter VEGABAR 82 - Slave sensor
• Ready-made connection cable, unassembled cable gland
• Documentation
– Quick setup guide VEGABAR 82
– Safety Manual (SIL)
– Documentation instrument parameters (default values)
– Documentation order-relating instrument parameters (deviation
from default values)
– Test certicate for pressure transmitters
– Instructions for optional instrument features
– Ex-specic "Safety instructions" (with Ex versions)
– If necessary, further certicates
Information:
Optional instrument features are also described in this operating
instructions manual. The respective scope of delivery results from the
order specication.
This operating instructions manual applies to the following instrument
versions:
• Hardware from 1.0.0
• Software version from 1.0.0
Note:
You can nd the hardware and software version of the instrument as
follows:
• On the type plate of the electronics module
• In the adjustment menu under "Info"
The type label contains the most important data for identication and
use of the instrument:
Scope of delivery
Scope of this operating
instructions
Type label

9
3 Product description
VEGABAR 82 • Slave sensor for electronic dierential pressure
48046-EN-190320
9
10
11
8
6
7
2
3
4
1
5
Fig. 1: Layout of the type label (example)
1 Instrument type and product code
2 Field for approvals
3 Power supply and signal output, electronics
4 Technical data
5 Order number
6 Serial number of the instrument
7 QR code
8 Symbol of the device protection class
9 ID numbers, instrument documentation
10 Reminder to observe the instrument documentation
11 SILidentication
The type label contains the serial number of the instrument. With it
you can nd the following instrument data on our homepage:
• Product code (HTML)
• Delivery date (HTML)
• Order-specic instrument features (HTML)
• Operating instructions, quick setup guide and Safety Manual at the
time of shipment (PDF)
• Test certicate (PDF) - optional
Move to "www.vega.com" and enter in the search eld the serial
number of your instrument.
Alternatively, you can access the data via your smartphone:
• Download the VEGA Tools app from the "Apple App Store" or the
"Google Play Store"
• Scan the Data Matrix code on the type label of the instrument or
• Enter the serial number manually in the app
3.2 Principle of operation
VEGABAR 82 is suitable for applications in virtually all industries. It is
used for the measurement of the following pressure types.
• Gauge pressure
• Absolute pressure
• Vacuum
Measured products are gases, vapours and liquids.
Depending on the process tting and measurement setup, measured
products can be also viscous or contain abrasive substances.
Serial number - Instru-
ment search
Application area
Measured products

10
3 Product description
VEGABAR 82 • Slave sensor for electronic dierential pressure
48046-EN-190320
The electronic dierential pressure measurement is suitable for the
measurement of the following process variables:
• Level
• Flow
• Dierential pressure
• Density
• Interface
• Level, density-compensated
The VEGABAR 82 slave sensor is combined with a sensor from the
instrument series for electronic dierential pressure measurement.
1
2
Fig.2:Example,electronicdierentialpressureforlevelmeasurementinpres-
surized vessel
1 VEGABAR 82
2 VEGABAR 82, slave sensor
The sensors are connected via a screened four-wire cable.The
measured value from the slave sensor is read in and factored into the
calculations. Power supply and parameter adjustment are carried out
through the master sensor.
Information:
The sensor versions "Relative pressure climate-compensated" as
well as "Double chamber housing" are not suitable for connection of a
slave sensor.
You can nd further information in chapter "Combination Master -
Slave " of this operating instructions.
Measured variables
Electronicdierential
pressure

11
3 Product description
VEGABAR 82 • Slave sensor for electronic dierential pressure
48046-EN-190320
To reach the Safety Integrity Level (SIL) for the electronic dierential
pressure, both instruments must be SIL-qualied.
The sensor element is the CERTEC®measuring cell with robust
ceramic diaphragm. The process pressure deects the ceramic
diaphragm and causes a capacitance change in the measuring cell.
This capacitance change is converted into an electrical signal and
outputted as measured value via the output signal.
16 µm
1
2
3
Fig.3:CongurationoftheCERTEC®measuring cell
1 Process diaphragm
2 Glass joint
3 Base element
The measuring cell is available in two sizes: CERTEC®(ø 28 mm) and
Mini-CERTEC®(ø 17.5 mm).
A temperature sensor in the ceramic diaphragm of the CERTEC®or
on the ceramic base of the Mini-CERTEC®measuring cell detects the
actual process temperature. The temperature value is output via the
master sensor.
Extreme process temperature jumps are also immediately detected
by the CERTEC® measuring cell. The values are compared with that
of an additional temperature measurement on the ceramic base body.
Within only a few measuring cycles the intelligent sensor electronics
compensates unavoidable measurement deviations due to tempera-
ture shocks. Such shocks cause (depending on the set damping) only
slight, brief changes to the output signal.
Relative pressure: the measuring cell is open to the atmosphere.
The ambient pressure is detected in the measuring cell and compen-
sated. It thus has no inuence on the measured value.
Absolute pressure: the measuring cell is evacuated and encapsu-
lated. The ambient pressure is not compensated and does hence
inuence the measured value.
The following presentations show examples for the installation of the
ceramic measuring cell into the process tting and the dierent seal
concepts.
Measuring system pres-
sure
Measuring system tem-
perature
Pressure types
Seal concepts

12
3 Product description
VEGABAR 82 • Slave sensor for electronic dierential pressure
48046-EN-190320
The recessed installation is particularly suitable for applications with
gases, vapours and clear liquids. The measuring cell seal is posi-
tioned laterally as well as in addition in front.
1
2
5
6
3
4
Fig. 4: Recessed installation of the measuring cell (example: manometer con-
nection G½)
1 Measuring cell
2 Seal for the measuring cell
3 Additional, front seal for measuring cell
4 Diaphragm
5 Processtting
6 Sealfortheprocesstting
The front-ush installation is particularly suitable for applications with
viscous and abrasive media and in case of buildup. The measuring
cell seal is positioned laterally.
2
3
4
1
5
Fig.5:Front-ushinstallationofthemeasuringcell(example:threadG1½)
1 Sealfortheprocesstting
2 Measuring cell
3 Seal for the measuring cell
4 Processtting
5 Diaphragm
The completely front-ush mounting is particularly suitable for ap-
plications in the paper industry. The diaphragm is in the pulp ow, is
hence cleaned and protected against buildup.
Recessed installation
Front-ushmountingwith
single seal
Completelyfront-ush
mounting with single seal

13
3 Product description
VEGABAR 82 • Slave sensor for electronic dierential pressure
48046-EN-190320
1
2
3
4
5
Fig.6:Front-ushinstallationofthemeasuringcell(example:M30x1.5)
1 Measuring cell
2 Seal for the measuring cell
3 Sealfortheprocesstting
4 Processtting
5 Diaphragm
The front-ush installation is particularly suitable for applications with
viscous media. The additional, front sealing protects the glass joint
of the measuring cell against chemical attack and the measuring cell
electronics against diusion of aggressive gases from the process.
1
2
3
45
Fig.7:Front-ushinstallationofthemeasuringcellwithdoubleseal(example:
angeconnectionwithextension)
1 Measuring cell
2 Seal for the measuring cell
3 Processtting
4 Additional, front seal for measuring cell
5 Diaphragm
The front-ush, hygienic installation of the measuring cell is particu-
larly suitable for food applications. The sealings are installed gap-free.
The form seal of the measuring cell protects also the glass joint.
1
2
3
4
5
Fig.8:Hygienicinstallationofthemeasuringcell(example:hygienicttingwith
compression nut)
1 Measuring cell
2 Form seal for the measuring cell
3 Gap-freesealforprocesstting
4 Processtting
5 Diaphragm
Front-ushmountingwith
double seal
Installation in hygienic
tting

14
3 Product description
VEGABAR 82 • Slave sensor for electronic dierential pressure
48046-EN-190320
The front-ush, hygienic installation of the measuring cell acc. to 3A
is particularly suitable for food applications. The sealings are installed
gap-free. The additional front sealing for the measuring cell protects
also the glass joint. A hole in the process tting is used for leakage
detection.
1
62
3
4
5
Fig. 9: Hygienic installation of the measuring cell acc. to 3-A (example: Clamp
connection)
1 Measuring cell
2 Seal for the measuring cell
3 Processtting
4 Additional, front seal for measuring cell
5 Diaphragm
5 Hole for leakage detection
3.3 Supplementary cleaning procedures
The VEGABAR 82 is also available in the version "Oil, grease and
silicone-free". These instruments have passed through a special
cleaning procedure to remove oil, grease and paint-wetting impair-
ment substances (PWIS).
The cleaning is carried out on all wetted parts as well as on surfaces
accessible from outside. To keep the purity level, the instruments are
immediately packed in plastic foil after the cleaning process. The
purity level remains as long as the instrument is kept in the closed
original packaging.
Caution:
The VEGABAR 82 in this version may not be used in oxygen ap-
plications. For this purpose, instruments are available in the special
version "Oil and grease-free for oxygen applications".
3.4 Packaging, transport and storage
Your instrument was protected by packaging during transport. Its
capacity to handle normal loads during transport is assured by a test
based on ISO 4180.
The packaging of standard instruments consists of environment-
friendly, recyclable cardboard. For special versions, PE foam or PE
foil is also used. Dispose of the packaging material via specialised
recycling companies.
Transport must be carried out in due consideration of the notes on the
transport packaging. Nonobservance of these instructions can cause
damage to the device.
The delivery must be checked for completeness and possible transit
damage immediately at receipt. Ascertained transit damage or con-
cealed defects must be appropriately dealt with.
Installation in hygienic
ttingacc.to3-A
Packaging
Transport
Transport inspection

15
3 Product description
VEGABAR 82 • Slave sensor for electronic dierential pressure
48046-EN-190320
Up to the time of installation, the packages must be left closed and
stored according to the orientation and storage markings on the
outside.
Unless otherwise indicated, the packages must be stored only under
the following conditions:
• Not in the open
• Dry and dust free
• Not exposed to corrosive media
• Protected against solar radiation
• Avoiding mechanical shock and vibration
• Storage and transport temperature see chapter "Supplement -
Technical data - Ambient conditions"
• Relative humidity 20 … 85 %
With instrument weights of more than 18 kg (39.68 lbs) suitable and
approved equipment must be used for lifting and carrying.
3.5 Accessories and replacement parts
The protective cover protects the sensor housing against soiling and
intense heat from solar radiation.
Screwed anges are available in dierent versions according to the
following standards: DIN 2501, EN 1092-1, BS 10, ASME B 16.5,
JIS B 2210-1984, GOST 12821-80.
Welded sockets are used to connect the sensors to the process,
threaded adapters for adaptation of the sensor with threaded tting
G¾ or G1½ to existing welded sockets.
Storage
Storage and transport
temperature
Lifting and carrying
Protective cover
Flanges
Welded sockets and
adapters

16
4 Mounting
VEGABAR 82 • Slave sensor for electronic dierential pressure
48046-EN-190320
4 Mounting
4.1 General instructions
Make sure before mounting that all parts of the instrument exposed to
the process are suitable for the existing process conditions.
These are mainly:
• Active measuring component
• Process tting
• Process seal
Process conditions in particular are:
• Process pressure
• Process temperature
• Chemical properties of the medium
• Abrasion and mechanical inuences
You can nd detailed information on the process conditions in chapter
"Technical data" as well as on the type label.
Protect your instrument against moisture ingress through the following
measures:
• Use a suitable connection cable (see chapter "Connecting to
power supply")
• Tighten the cable gland or plug connector
• When mounting horizontally, turn the housing so that the cable
gland or plug connector point downward
• Lead the connection cable downward in front of the cable entry or
plug connector
This applies mainly to outdoor installations, in areas where high
humidity is expected (e.g. through cleaning processes) and on cooled
or heated vessels.
To maintain the housing protection, make sure that the housing lid is
closed during operation and locked, if necessary.
Make sure that the degree of contamination specied in chapter
"Technical data" meets the existing ambient conditions.
On devices with a threaded tting, the hexagon on the process tting
must be tightened with a suitable wrench.
See chapter "Dimensions" for wrench size.
Warning:
The housing or the electrical connection may not be used for screw-
ing in! Tightening can cause damage, e. g. to the rotation mechanism
of the housing.
If there is strong vibration at the mounting location, the instrument
version with external housing should be used. See chapter "External
housing".
Process conditions
Protection against mois-
ture
Screwing in
Vibrations

17
4 Mounting
VEGABAR 82 • Slave sensor for electronic dierential pressure
48046-EN-190320
Higher process temperatures often mean also higher ambient
temperatures. Make sure that the upper temperature limits stated in
chapter "Technical data" for the environment of the electronics hous-
ing and connection cable are not exceeded.
1
2
Fig. 10: Temperature ranges
1 Process temperature
2 Ambient temperature
4.2 Ventilation and pressure compensation
The lter element in the electronics housing has the following func-
tions:
• Ventilation of the electronics housing
• Atmospheric pressure compensation (with relative pressure meas-
uring ranges)
Caution:
The lter element causes a time-delayed pressure compensation.
When quickly opening/closing the housing cover, the measured value
can change for approx. 5 s by up to 15 mbar.
For an eective ventilation, the lter element must be always free from
buildup. In case of horizontal mounting, turn the housing so that the
lter element points downward after the instrument is installed. This
provides better protection against buildup.
Caution:
Do not use a high-pressure cleaner. The lter element could be dam-
aged, which would allow moisture into the housing.
The following paragraphs describe how the lter element is arranged
in the dierent instrument versions.
Temperature limits
Filter element - Function

18
4 Mounting
VEGABAR 82 • Slave sensor for electronic dierential pressure
48046-EN-190320
1 2 3
4 4 4
Fig.11:Positionofthelterelement-non-Ex,Ex-iaversion
1 Plastic, stainless steel housing (precision casting)
2 Aluminium housing
3 Stainless steel housing (electropolished)
4 Filter element
With the following instruments a blind plug is installed instead of the
lter element:
• Instruments in protection IP 66/IP 68 (1 bar) - ventilation via capil-
laries in non-detachable cable
• Instruments with absolute pressure
→ Turn the metal ring in such a way that the lter element points
downward after installation of the instrument. This provides better
protection against buildup.
1
2
Fig.12:Positionofthelterelement-Ex-dversion
1 Rotatable metal ring
2 Filter element
Instruments with absolute pressure have a blind plug mounted
instead of the lter element.
The process assembly of instruments with Second Line of Defense
(gastight leadthrough) is completely encapsulated. An absolute pres-
sure measuring cell is used so that no ventilation is required.
Filter element - Position
Filter element - Position
Ex-d version
Instruments with Second
Line of Defense

19
4 Mounting
VEGABAR 82 • Slave sensor for electronic dierential pressure
48046-EN-190320
1
2
Fig.13:Positionofthelterelement-gastightleadthrough
1 Filter element
1
Fig.14:Positionofthelterelement-IP69Kversion
1 Filter element
Instruments with absolute pressure have a blind plug mounted
instead of the lter element.
4.3 Combination Master - Slave
In principle, any sensor combination within the instrument series is
allowed. The following requirements must be fullled:
• Conguration, Master sensor suitable for electronic dierential
pressure
• Pressure type is identical for both sensors, i.e. relative pressure/
relative pressure or absolute pressure/absolute pressure
• Master sensor measures the higher pressure
• Measurement setup as shown in the following chapters
The measuring range of each sensor is selected such that it ts the
measuring loop. For this, the max. recommended turn down must be
noted. See chapter "Technical data". It is absolutely necessary the the
measuring ranges of Master and Slave correspond.
Measurement result = Measured value of Master (total pres-
sure) - measured value of Slave (static pressure)
Depending on the application, individual combinations can result, see
following examples:
Data
Application: Level measurement
Medium: Water
Filter element - Position
IP 69K version
Example - large vessel

20
4 Mounting
VEGABAR 82 • Slave sensor for electronic dierential pressure
48046-EN-190320
Vessel height: 12 m, hydrostatic pressure = 12 m x 1000 kg/m3x
9.81 m/s2 = 117.7 kPa = 1.18 bar
Superimposed pressure: 1 bar
Total pressure: 1.18 bar + 1 bar = 2.18 bar
Instrument selection
Nominal measuring range Master: 2.5 bar
Nominal measuring range Slave: 1 bar
Turn Down: 2.5 bar/1.18 bar = 2.1 : 1
Data
Application: Level measurement
Medium: Water
Vessel height: 500 mm, hydrostatic pressure = 0.50 m x 1000 kg/m3x
9.81 m/s2 = 4.9 kPa = 0.049 bar
Superimposed pressure: 350 mbar = 0.35 bar
Total pressure: 0.049 bar + 0.35 bar = 0.399 bar
Instrument selection
Nominal measuring range Master: 0.4 bar
Nominal measuring range Slave: 0.4 bar
Turn Down: 0.4 bar /0.049 bar = 8.2 : 1
Data
Application: Dierential pressure measurement
Medium: Gas
Static pressure: 0.8 bar
Dierential pressure on orice: 50 mbar = 0.050 bar
Total pressure: 0.8 bar + 0.05 bar = 0.85 bar
Instrument selection
Nominal measuring range Master: 1 bar
Nominal measuring range Slave: 1 bar
Turn Down: 1 bar/0.050 bar = 20 : 1
The measuring result (level, pressure dierence) as well as meas-
ured value Slave (static or superimposed pressure) are output by the
sensor. Depending on the instrument version, output as 4 … 20 mA
signal or digitally via HART, Probus PA or Foundation Fieldbus.
To reach the Safety Integrity Level (SIL) for the electronic dierential
pressure, both instruments must be SIL-qualied.
4.4 Level measurement
The master/slave combination is suitable for level measurement in a
pressurized vessel
Keep the following in mind when setting up the measuring system:
• Mount the master sensor below the min. level
Example - small vessel
Example-oricein
pipeline
Output measured values
Measurement setup