Vega VEGABAR 81 User manual

Operating Instructions
Pressure transmitter with chemical seal
VEGABAR 81
4 … 20 mA
Document ID: 45025

2
Contents
VEGABAR 81 • 4 … 20 mA
45025-EN-210430
Contents
1 Zu diesem Dokument............................................................................................................... 4
1.1 Funktion ........................................................................................................................... 4
1.2 Zielgruppe........................................................................................................................ 4
1.3 Verwendete Symbolik....................................................................................................... 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................................................................................................................... 5
2.6 NAMUR recommendations .............................................................................................. 6
2.7 Installation and operation in the USA and Canada ........................................................... 6
2.8 Environmental instructions ............................................................................................... 6
3 Product description ................................................................................................................. 7
3.1 Conguration.................................................................................................................... 7
3.2 Principle of operation........................................................................................................ 8
3.3 Supplementary cleaning procedures.............................................................................. 11
3.4 Packaging, transport and storage................................................................................... 11
3.5 Accessories.................................................................................................................... 12
4 Mounting................................................................................................................................. 14
4.1 General instructions ....................................................................................................... 14
4.2 Instructions for oxygen applications ............................................................................... 15
4.3 Ventilation and pressure compensation.......................................................................... 16
4.4 Process pressure measurement..................................................................................... 18
4.5 Level measurement........................................................................................................ 20
4.6 External housing ............................................................................................................ 21
5 Connecting to power supply................................................................................................. 22
5.1 Preparing the connection ............................................................................................... 22
5.2 Connecting..................................................................................................................... 23
5.3 Single chamber housing................................................................................................. 24
5.4 Ex-d-ia double chamber housing.................................................................................... 25
5.5 Housing IP66/IP68 (1 bar) .............................................................................................. 26
5.6 External housing with version IP68 (25 bar) ................................................................... 26
5.7 Switch-on phase............................................................................................................. 28
6 Set up with the display and adjustment module ................................................................ 29
6.1 Insert display and adjustment module............................................................................ 29
6.2 Adjustment system......................................................................................................... 30
6.3 Measured value indication.............................................................................................. 31
6.4 Parameter adjustment - Quick setup .............................................................................. 32
6.5 Parameter adjustment - Extended adjustment................................................................ 32
6.6 Menu overview ............................................................................................................... 44
6.7 Saving the parameterisation data................................................................................... 45
7 Setup with PACTware............................................................................................................. 47
7.1 Connect the PC.............................................................................................................. 47
7.2 Parameter adjustment with PACTware............................................................................ 47
7.3 Saving the parameterisation data................................................................................... 48

3
Contents
VEGABAR 81 • 4 … 20 mA
45025-EN-210430
8 Set up with other systems .................................................................................................... 49
8.1 DD adjustment programs ............................................................................................... 49
8.2 Field Communicator 375, 475 ........................................................................................ 49
9 Diagnostics and servicing .................................................................................................... 50
9.1 Maintenance .................................................................................................................. 50
9.2 Diagnosis function.......................................................................................................... 50
9.3 Rectify faults................................................................................................................... 52
9.4 Exchange process module on version IP68 (25 bar) ...................................................... 53
9.5 Exchanging the electronics module................................................................................ 54
9.6 Software update ............................................................................................................. 54
9.7 How to proceed if a repair is necessary.......................................................................... 55
10 Dismount................................................................................................................................. 56
10.1 Dismounting steps.......................................................................................................... 56
10.2 Disposal ......................................................................................................................... 56
11 Supplement ............................................................................................................................ 57
11.1 Technical data ................................................................................................................ 57
11.2 Chemical seal with vacuum applications........................................................................ 66
11.3 Dimensions .................................................................................................................... 70
11.4 Gewerbliche Schutzrechte ............................................................................................. 78
11.5 Trademark ...................................................................................................................... 78
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: 2021-03-31

4
1 Zu diesem Dokument
VEGABAR 81 • 4 … 20 mA
45025-EN-210430
1 Zu diesem Dokument
1.1 Funktion
Die vorliegende Anleitung liefert Ihnen die erforderlichen Informa-
tionen für Montage, Anschluss und Inbetriebnahme sowie wichtige
Hinweise für Wartung, Störungsbeseitigung, den Austausch von
Teilen und die Sicherheit des Anwenders. Lesen Sie diese deshalb
vor der Inbetriebnahme und bewahren Sie sie als Produktbestandteil
in unmittelbarer Nähe des Gerätes jederzeit zugänglich auf.
1.2 Zielgruppe
Diese Betriebsanleitung richtet sich an ausgebildetes Fachpersonal.
Der Inhalt dieser Anleitung muss dem Fachpersonal zugänglich
gemacht und umgesetzt werden.
1.3 Verwendete Symbolik
Document ID
Dieses Symbol auf der Titelseite dieser Anleitung weist auf die Docu-
ment ID hin. Durch Eingabe der Document ID auf www.vega.com
kommen Sie zum Dokumenten-Download.
Information, Hinweis, Tipp: Dieses Symbol kennzeichnet hilfreiche
Zusatzinformationen und Tipps für erfolgreiches Arbeiten.
Hinweis: Dieses Symbol kennzeichnet Hinweise zur Vermeidung von
Störungen, Fehlfunktionen, Geräte- oder Anlagenschäden.
Vorsicht: Nichtbeachten der mit diesem Symbol gekennzeichneten
Informationen kann einen Personenschaden zur Folge haben.
Warnung: Nichtbeachten der mit diesem Symbol gekennzeichneten
Informationen kann einen ernsthaften oder tödlichen Personen-
schaden zur Folge haben.
Gefahr: Nichtbeachten der mit diesem Symbol gekennzeichneten In-
formationen wird einen ernsthaften oder tödlichen Personenschaden
zur Folge haben.
Ex-Anwendungen
Dieses Symbol kennzeichnet besondere Hinweise für Ex-Anwendun-
gen.
• Liste
Der vorangestellte Punkt kennzeichnet eine Liste ohne zwingende
Reihenfolge.
1 Handlungsfolge
Vorangestellte Zahlen kennzeichnen aufeinander folgende Hand-
lungsschritte.
Batterieentsorgung
Dieses Symbol kennzeichnet besondere Hinweise zur Entsorgung
von Batterien und Akkus.

5
2 For your safety
VEGABAR 81 • 4 … 20 mA
45025-EN-210430
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
The VEGABAR 81 is a pressure transmitter for process pressure and
hydrostatic level 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.
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.
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.

6
2 For your safety
VEGABAR 81 • 4 … 20 mA
45025-EN-210430
The EU conformity declaration can be found on our homepage.
Duetothedesignofitsprocessttings,thedevicedoesnotsubject
of EU pressure device directive if it is operated at process pressures
≤200bar.1)
2.6 NAMUR recommendations
NAMUR is the automation technology user association in the process
industry in Germany. The published NAMUR recommendations are
acceptedasthestandardineldinstrumentation.
ThedevicefullstherequirementsofthefollowingNAMURrecom-
mendations:
• NE 21 – Electromagnetic compatibility of equipment
• NE 43 – Signal level for fault information from measuring transduc-
ers
• NE53–Compatibilityofelddevicesanddisplay/adjustment
components
• NE107–Self-monitoringanddiagnosisofelddevices
For further information see www.namur.de.
2.7 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).
Installations in Canada shall comply with the relevant requirements of
the Canadian Electrical Code
A Class 2 power supply unit has to be used for the installation in the
USA and Canada.
2.8 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"
1) Exception:Versions with measuring ranges from 250 bar. These are subject
of the EU Pressure Device Directive.

7
3 Product description
VEGABAR 81 • 4 … 20 mA
45025-EN-210430
3 Product description
3.1 Conguration
The scope of delivery encompasses:
• VEGABAR 81 pressure transmitter
• Ventilation valves, closing screws – depending on version (see
chapter "Dimensions")
The further scope of delivery encompasses:
• Documentation
– Quick setup guide VEGABAR 81
– 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 from 1.3.5
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

8
3 Product description
VEGABAR 81 • 4 … 20 mA
45025-EN-210430
7
6
4
5
2
3
1
Fig. 1: Layout of the type label (example)
1 Product code
2 Field for approvals
3 Technical data
4 Serial number of the instrument
5 QR code
6 Symbol of the device protection class
7 ID numbers, instrument documentation
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 and quick setup guide at the time of ship-
ment (PDF)
• Order-specicsensordataforanelectronicsexchange(XML)
• 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 DataMatrix code on the type label of the instrument or
• Enter the serial number manually in the app
3.2 Principle of operation
VEGABAR 81 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.
The chemical seal systems of VEGABAR 81, which are optimally
adapted to the process, also allow measurement of highly corrosive
and hot products.
The VEGABAR 81 is suitable for the measurement of the following
process variables:
Serial number - Instru-
ment search
Application area
Measured products
Measured variables

9
3 Product description
VEGABAR 81 • 4 … 20 mA
45025-EN-210430
• Process pressure
• Level
Fig. 2: Process pressure measurement VEGABAR 81
Depending on the version, the VEGABAR 81 is also suitable for
electronicdierentialpressuremeasurement.Forthis,theinstrument
is combined with a Secondary sensor.
Fig. 3: Electronic dierential pressure measurement via a Primary/Secondary
sensor combination
Youcannddetailedinformationintheoperatinginstructionsofthe
respective Secondary sensor.
The VEGABAR 81 is equipped with a chemical seal. It consists of a
stainless steel diaphragm and a transmission liquid.
A chemical seal has two tasks:
• Separation of the sensor element from the medium
• Transmission of the process pressure to the sensor element
Electronicdierential
pressure
Chemical seal

10
3 Product description
VEGABAR 81 • 4 … 20 mA
45025-EN-210430
1
2
3
4
Fig. 4: Conguration of a chemical seal
1 Sensor element
2 Sealed screw
3 Transmission liquid
4 Stainless steel diaphragm
Thechemicalsealisavailableindierentversions,seechapter"
Dimensions".
The process pressure acts on the sensor element via the isolat-
ing diaphragm.The process pressure causes a resistance change
which is converted into a corresponding output signal and output as
measured value.
Measuring ranges up to 40 bar: piezoresistive sensor element with
a transmission liquid, measuring ranges from 100 bar: a dry strain
gauge (DMS) sensor element.
1
3 4
2
Fig. 5: Conguration of a measuring system with piezoresistive sensor element
1 Sensor element
2 Base element
3 Transmission liquid
4 Diaphragm
Measuring system

11
3 Product description
VEGABAR 81 • 4 … 20 mA
45025-EN-210430
1
2
3
Fig. 6: Conguration of a measuring system with strain gauge (DMS) sensor
element
1 Sensor element
2 Process diaphragm
3 Pressure cylinder
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 contains vacuum and is
encapsulated. The ambient pressure is not compensated and does
henceinuencethemeasuredvalue.
The measuring system is completely welded and thus sealed against
the process.
Theprocessttingissealedagainsttheprocessbyasuitableseal.It
mustbeprovidedbythecustomer,dependingontheprocesstting
also included in the scope of delivery, see chapter "Technical data",
"Materials and weights".
3.3 Supplementary cleaning procedures
The VEGABAR 81 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 81 in this version may not be used in oxygen ap-
plications. For this purpose, instruments are available in the special
version "Oil, grease and silicone-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.
Pressure types
Seal concept
Packaging

12
3 Product description
VEGABAR 81 • 4 … 20 mA
45025-EN-210430
The packaging consists of environment-friendly, recyclable card-
board. 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.
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
The instructions for the listed accessories can be found in the down-
load area on our homepage.
The display and adjustment module is used for measured value indi-
cation, adjustment and diagnosis.
The integrated Bluetooth module (optional) enables wireless adjust-
ment via standard adjustment devices.
The interface adapter VEGACONNECT enables the connection of
communication-capable instruments to the USB interface of a PC.
The VEGADIS 82 is suitable for measured value indication of
4 … 20 mA and 4 … 20 mA/HART sensors. It is looped into the signal
cable.
The overvoltage arrester B81-35 is used instead of the terminals in
the single or double chamber housing.
The protective cover protects the sensor housing against soiling and
intense heat from solar radiation.
Transport
Transport inspection
Storage
Storage and transport
temperature
Lifting and carrying
PLICSCOM
VEGACONNECT
VEGADIS 82
Overvoltage protection
Protective cover

13
3 Product description
VEGABAR 81 • 4 … 20 mA
45025-EN-210430
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 devices to the process,
threaded and hygienic adapters for easy adaptation of devices with
standardthreadedttings,e.g.tohygienicconnectionsonthepro-
cess side.
Flanges
Welded socket, threaded
and hygienic adapter

14
4 Mounting
VEGABAR 81 • 4 … 20 mA
45025-EN-210430
4 Mounting
4.1 General instructions
Note:
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" of the operating
instructions or on the type label.
Hence make sure before mounting that all parts of the instrument ex-
posed 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
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
• 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.
Note:
Make sure that during installation or maintenance no moisture or dirt
can get inside the instrument.
To maintain the housing protection, make sure that the housing lid is
closed during operation and locked, if necessary.
Deviceswiththreadedttingarescrewedintotheprocessttingwith
a suitable wrench via the hexagon.
See chapter "Dimensions" for wrench size.
Warning:
The housing or the electrical connection may not be used for screw-
ing in! Depending on the device version, tightening can cause dam-
age, e. g. to the rotation mechanism of the housing.
Avoid damages on the device by lateral forces, for example by vibra-
tions.Itisthusrecommendedtoxthedeviceswithprocesstting
Process conditions
Protection against mois-
ture
Screwing in
Vibrations

15
4 Mounting
VEGABAR 81 • 4 … 20 mA
45025-EN-210430
thread G½ of plastic at the installation site via a suitable measuring
instrument holder.
If there is strong vibration at the mounting location, the instrument
version with external housing should be used. See chapter "External
housing".
Thepermissibleprocesspressurerangeisspeciedby"MWP"(Maxi-
mum Working Pressure) on the type label, see chapter "Structure".
The MWP takes the element of the measuring cell and processing
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, a 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.
The permissible process pressure range is stated on the type label.
The instrument should only be operated with these pressures if the
mountingaccessoryusedalsofullsthesevalues.Thisshouldbeen-
suredbysuitableanges,weldedsockets,tensionringswithClamp
connections, sealings, etc.
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. 7: Temperature ranges
1 Process temperature
2 Ambient temperature
4.2 Instructions for oxygen applications
Oxygen and other gases can be explosive when brought into contact
with oils, grease and plastics, so the following measures must also be
taken:
Permissible process
pressure (MWP) - Device
Permissible process
pressure (MWP) - Mount-
ing accessory
Temperature limits
Oxygen applications

16
4 Mounting
VEGABAR 81 • 4 … 20 mA
45025-EN-210430
• All components of the system, e.g. measuring instruments, must
be cleaned in accordance with the requirements of recognized
regulations or standards
• Depending on the seal material, certain temperatures and pres-
sures must not be exceeded in oxygen applications, see chapter
"Technical data"
Danger:
Instruments for oxygen applications must be unpacked just before
mounting.Afterremovingtheprotectivecoveroftheprocesstting,
the label "O2"willbevisibleontheprocesstting.Penetrationofoil,
grease and dirt should be avoided. Danger of explosion!
4.3 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.
Filter element - Function

17
4 Mounting
VEGABAR 81 • 4 … 20 mA
45025-EN-210430
1 2 3
6
6
6 6
6
5
4
Fig. 8: Position of the lter element
1 Plastic, stainless steel single chamber (precision casting)
2 Aluminium - single chamber
3 Stainless steel single chamber (electropolished)
4 Plastic double chamber
5 Aluminium, stainless steel double chamber housing (precision casting)
6 Filter element
With the following instruments a blind plug is installed instead of the
lterelement:
• Instruments in protection IP66/IP68 (1 bar) - ventilation via capillar-
ies 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. 9: 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.
Filter element - Position
Filter element - Position
Ex-d version

18
4 Mounting
VEGABAR 81 • 4 … 20 mA
45025-EN-210430
The Second Line of Defense (SLOD) is a second level of the process
separation in form of a gas-tight leadthrough in the housing neck,
preventing products from penetrating into the housing.
With these instruments, the process assembly is completely en-
capsulated. An absolute pressure measuring cell is used so that no
ventilation is required.
With relative pressure measuring ranges, the ambient pressure is
detected and compensated by a reference sensor in the electronics.
1
2
1
2
Fig. 10: Position of the lter element - gastight leadthrough
1 Filter element
2 Gas-tight leadthrough
1
Fig. 11: Position of the lter element - IP69K version
1 Filter element
Instruments with absolute pressure have a blind plug mounted
insteadofthelterelement.
4.4 Process pressure measurement
Keep the following in mind when setting up the measuring system:
• Mount the instrument above the measuring point
Possiblecondensationcanthendrainointotheprocessline.
Filter element - Position
Second Line of Defense
Filter element - Position
IP69K version
Measurement setup in
gases

19
4 Mounting
VEGABAR 81 • 4 … 20 mA
45025-EN-210430
1
2
3
Fig. 12: Measurement setup for process pressure measurement of gases in
pipelines
1 VEGABAR 81
2 Blocking valve
3 Pipeline
Keep the following in mind when setting up the measuring system:
• Connect via a siphon
• Do not insulate the siphon
• Fill the siphon with water before setup
1
4
3
2
1
2
3
4
Fig. 13: Measurement setup for the process pressure measurement of gases in
pipelines
1 VEGABAR 81
2 Blocking valve
3 Siphon in U or circular form
4 Pipeline
A protective accumulation of water is formed through condensation
in the pipe bends. Even in applications with hot steam, a medium
temperature < 100 °C on the transmitter is ensured.
Measurement setup in
vapours

20
4 Mounting
VEGABAR 81 • 4 … 20 mA
45025-EN-210430
Keep the following in mind when setting up the measuring system:
• Mount the instrument below the measuring point
Theeectivepressurelineisalwayslledwithliquidandgasbubbles
can bubble up to the process line.
3
1
2
Fig. 14: Measurement setup for the process pressure measurement of liquids in
pipelines
1 VEGABAR 81
2 Blocking valve
3 Pipeline
4.5 Level measurement
Keep the following in mind when setting up the measuring system:
• Mount the instrument below the min. level
• Donotmounttheinstrumentclosetothellingstreamoremptying
area
• Mount the instrument so that it is protected against pressure
shocks from the stirrer
Fig. 15: Measurement setup for the level measurement
Measurement setup in
liquids
Measurement setup