Vega VEGAFLEX 81 User manual

Operating Instructions
TDR sensor for continuous level and
interface measurement of liquids
VEGAFLEX 81
4 … 20 mA/HART two-wire
Document ID: 41824

2
Quick start
VEGAFLEX 81 • 4 … 20 mA/HART two-wire
41824-EN-130612
Quick start
The quick start procedure enables a quick setup with many applica-
tions. You can nd further information in the respective chapters of the
operating instructions manual.
1. Distance from the metallic vessel wall > 300 mm. Distance from
non-metallic vessel wall > 500 mm. The probe must not touch any
installations or the vessel wall.
2. In non-metallic vessels, place a metal sheet beneath the process
tting.
1 2
Fig. 1: Installation in non-metallic vessel
1 Flange
2 Metal sheet
3. If necessary, fasten probe end.
For further information see chapter "Mounting".
1. Make sure that the power supply corresponds to the specica-
tions on the type label.
2. Connect the instrument according to the following illustration
5
12
+
( ) (-)
678
4...20mA
2
3
4
1
Fig. 2: Electronics and connection compartment, single chamber housing
1 Voltage supply, signal output
2 For display and adjustment module or interface adapter
3 For external display and adjustment unit
4 Ground terminal for connection of the cable screen
See also chapter "Connecting to power supply"
For standard applications we recommend selecting the "Quick setup"
in the display and adjustment module.
Mounting
Electrical connection
Set parameters

3
Quick start
VEGAFLEX 81 • 4 … 20 mA/HART two-wire
41824-EN-130612
1. In this menu item you can select the application.You can choose
between level and interface measurement.
2. In the menu item "Medium - Dielectric constant" you can dene
the medium type (medium).
3. Carry out the adjustment in the menu items "Min. adjustment" and
"Max. adjustment".
4. A "Linearization" is recommended for all vessels in which the
vessel volume does not increase linearly with the level - e.g. in a
horizontal cylindrical or spherical tank. Activate the appropriate
curve.
5. A "False signal suppression" detects, marks and saves the false
signals so that they are no longer taken into account for level
measurement. We generally recommend a false signal suppres-
sion.
The sensor measures the distance from the sensor (reference plane)
to the product surface. See also chapter "Parameter adjustment".
2
4
5
3
2
4
5
3
11
Fig. 3: Measuring ranges - VEGAFLEX 81
1 Reference plane
2 Probe length L
3 Measuring range (default setting refers to the measuring range in water)
4 Upper dead band (in this area no measurement is possible)
5 Lower dead band (in this area no measurement is possible)
For this adjustment, the distance is entered when the vessel is full
and nearly empty. If these values are not known, an adjustment with
other distances, for example, 10 % and 90 % is also possible. Starting
Parameterization example

4
Quick start
VEGAFLEX 81 • 4 … 20 mA/HART two-wire
41824-EN-130612
point for these distance specications is always the seal surface of
the thread or ange.
1. In the menu "Additional settings", menu item "Damping" you can
adjust the requested damping of the output signal.
2. Select the parameter of the current output and the output charac-
teristics in the menu item "Current output".
Further steps

5
Contents
VEGAFLEX 81 • 4 … 20 mA/HART two-wire
41824-EN-130612
Contents
1 About this document
1.1 Function ........................................................................................................................... 7
1.2 Target group ..................................................................................................................... 7
1.3 Symbolism used............................................................................................................... 7
2 For your safety
2.1 Authorised personnel ....................................................................................................... 8
2.2 Appropriate use................................................................................................................ 8
2.3 Warning about incorrect use............................................................................................. 8
2.4 General safety instructions............................................................................................... 8
2.5 CE conformity................................................................................................................... 8
2.6 NAMUR recommendations .............................................................................................. 9
2.7 Environmental instructions ............................................................................................... 9
3 Product description
3.1 Conguration.................................................................................................................. 10
3.2 Principle of operation...................................................................................................... 11
3.3 Packaging, transport and storage................................................................................... 14
3.4 Accessories and replacement parts ............................................................................... 14
4 Mounting
4.1 General instructions ....................................................................................................... 17
4.2 Mounting instructions ..................................................................................................... 17
5 Connecting to power supply
5.1 Preparing the connection ............................................................................................... 24
5.2 Connecting..................................................................................................................... 25
5.3 Wiring plan, single chamber housing.............................................................................. 27
5.4 Wiring plan, double chamber housing ............................................................................ 27
5.5 Wiring plan, Ex-d-ia double chamber housing................................................................ 29
5.6 Wiring plan - version IP 66/IP 68, 1 bar........................................................................... 30
5.7 Supplementary electronics............................................................................................. 31
5.8 Switch-on phase............................................................................................................. 31
6 Set up with the display and adjustment module
6.1 Insert display and adjustment module............................................................................ 33
6.2 Adjustment system......................................................................................................... 34
6.3 Parameter adjustment - Quick setup .............................................................................. 35
6.4 Parameter adjustment - Extended adjustment................................................................ 38
6.5 Saving the parameter adjustment data........................................................................... 57
7 Setup with PACTware
7.1 Connect the PC.............................................................................................................. 58
7.2 Parameter adjustment with PACTware............................................................................ 59
7.3 Set up with the quick setup............................................................................................. 60
7.4 Saving the parameter adjustment data........................................................................... 64
8 Set up with other systems
8.1 DD adjustment programs ............................................................................................... 65
8.2 Field Communicator 375, 475 ........................................................................................ 65
9 Diagnostics and service
9.1 Maintenance .................................................................................................................. 66

6
Contents
VEGAFLEX 81 • 4 … 20 mA/HART two-wire
41824-EN-130612
9.2 Diagnosis memory ......................................................................................................... 66
9.3 Status messages............................................................................................................ 67
9.4 Rectify faults................................................................................................................... 71
9.5 Exchanging the electronics module................................................................................ 74
9.6 Exchanging the cable/rod............................................................................................... 75
9.7 Software update ............................................................................................................. 76
9.8 How to proceed in case of repair.................................................................................... 77
10 Dismounting
10.1 Dismounting steps.......................................................................................................... 78
10.2 Disposal ......................................................................................................................... 78
11 Supplement
11.1 Technical data ................................................................................................................ 79
11.2 Dimensions .................................................................................................................... 90
Safety instructions for Ex areas
Please note the Ex-specic safety information for installation and op-
eration in Ex areas. These safety instructions are part of the operating
instructions manual and come with the Ex-approved instruments.
Editing status: 2013-06-11

7
1 About this document
VEGAFLEX 81 • 4 … 20 mA/HART two-wire
41824-EN-130612
1 About this document
1.1 Function
This operating instructions manual provides all the information you
need for mounting, connection and setup as well as important instruc-
tions for maintenance and fault rectication. Please read this informa-
tion 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 specialist
personnel. The contents of this manual should be made available to
these personnel and put into practice by them.
1.3 Symbolism used
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.

8
2 For your safety
VEGAFLEX 81 • 4 … 20 mA/HART two-wire
41824-EN-130612
2 For your safety
2.1 Authorised personnel
All operations described in this operating instructions manual must
be carried out only by trained specialist 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
VEGAFLEX 81 is a sensor for continuous level measurement.
You can nd detailed information on the application range 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 the instrument can give rise to
application-specic hazards, e.g. vessel overll or damage to system
components through incorrect mounting or adjustment.
2.4 General safety instructions
This is a state-of-the-art instrument complying with all prevailing
regulations and guidelines. The instrument must only be operated in a
technically awless and reliable condition. The operator is responsible
for the trouble-free operation of the instrument.
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.
The safety approval markings and safety tips on the device must also
be observed.
2.5 CE conformity
The device fullls the legal requirements of the applicable EC guide-
lines. By axing the CE marking, we conrm successful testing of the
product.
You can nd the CE Certicate of Conformity in the download section
of our homepage.

9
2 For your safety
VEGAFLEX 81 • 4 … 20 mA/HART two-wire
41824-EN-130612
Electromagnetic compatibility
Instruments with plastic housing as well as in four-wire or Ex-d-ia
version are designed for use in an industrial environment. Neverthe-
less, electromagnetic interference from electrical conductors and
radiated emissions must be taken into account, as is usual with a
class A instrument according to EN 61326-1. If the instrument is used
in a dierent environment, the electromagnetic compatibility to other
instruments must be ensured by suitable measures.
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lls the requirements of the following NAMUR recom-
mendations:
• NE 21 – Electromagnetic compatibility of equipment
• NE 43 – Signal level for malfunction information from measuring
transducers
• 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 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ll this obligation by observing the environmental
instructions in this manual:
• Chapter "Packaging, transport and storage"
• Chapter "Disposal"

10
3 Product description
VEGAFLEX 81 • 4 … 20 mA/HART two-wire
41824-EN-130612
3 Product description
3.1 Conguration
The nameplate contains the most important data for identication and
use of the instrument:
2
1
13
14
15
16
12
11
5
3
6
4
7
8
9
10
Fig. 4: Layout of the type label (example)
1 Instrument type
2 Product code
3 Approvals
4 Power supply and signal output, electronics
5 Protection rating
6 Probe length
7 Process and ambient temperature, process pressure
8 Material, wetted parts
9 Hardware and software version
10 Order number
11 Serial number of the instrument
12 Symbol of the device protection class
13 ID numbers, instrument documentation
14 Reminder to observe the instrument documentation
15 NotiedauthorityforCEmarking
16 Approval directives
With the serial number of the instrument on the type label you can nd
the following data on our homepage:
• Article number of the instrument (HTML)
• Delivery date (HTML)
• Order-specic instrument features (HTML)
• Operating instructions at the time of shipment (PDF)
• Order-specic sensor data for an electronics exchange (XML)
• Test certicate pressure transmitters (PDF)
Go to www.vega.com, "VEGA Tools" and "Serial number search".
As an alternative, you can nd the data via your Smartphone:
• Download the Smartphone-App "VEGA Tools" 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 into the App
Type plate
Serial number

11
3 Product description
VEGAFLEX 81 • 4 … 20 mA/HART two-wire
41824-EN-130612
This operating instructions manual applies to the following instrument
versions:
• Hardware from 1.0.0
• Software from 1.0.0
• Only for instrument versions without SIL qualication
The instrument and the electronics version can be determined via the
product code on the type label as well as on the electronics.
• Standard electronics: Type FX80H.-
The scope of delivery encompasses:
• Sensor
• Documentation
– this operating instructions manual
– Test certicate measuring accuracy (optional)
– Operating instructions manual "Display and adjustment mod-
ule" (optional)
– Supplementary instructions "GSM/GPRS radio module"
(optional)
– Supplementary instructions manual "Heating for display and
adjustment module" (optional)
– Supplementary instructions manual "Plug connector for con-
tinuously measuring sensors" (optional)
– Ex-specic "Safety instructions" (with Ex versions)
– if necessary, further certicates
3.2 Principle of operation
The VEGAFLEX 81 is a level sensor with cable or rod probe for
continuous level or interface measurement, suitable for applications
in liquids.
High frequency microwave pulses are guided along a steel cable or
a rod. Upon reaching the product surface, the microwave pulses are
reected. The running time is evaluated by the instrument and output-
ted as level.
Scope of this operating
instructions manual
Versions
Scope of delivery
Application area
Functional principle -
level measurement

12
3 Product description
VEGAFLEX 81 • 4 … 20 mA/HART two-wire
41824-EN-130612
d
h
1
Fig. 5: Level measurement
1 Sensorreferenceplane(sealsurfaceoftheprocesstting)
d Distance to the interface (HART value 1)
h Height - Level
Probe end tracking
To increase sensitivity, the probe is equipped with probe end tracking.
In products with a low dielectric constant, this function is very helpful.
This is the case, for example, in plastic granules, packing chips or in
vessels with uidized products.
Between a dielectric constant of 1.5 and 3, the function switches on, if
required. As soon as the level echo can no longer be detected, probe
end tracking is automatically activated. The measurement is contin-
ued with the last calculated dielectric constant.
The accuracy thus depends on the stability of the dielectric constant.
If you measure a medium with a dielectric constant below 1.5, probe
end tracking is always active. In this case, you have to enter the
dielectric constant of the medium. A stable dielectric constant is very
important here.
High frequency microwave impulses are guided along a steel cable or
rod. Upon reaching the product surface, a part of the microwave im-
pulses is reected. The other part passes through the upper product
and is reected by the interface. The running times to the two product
layers are processed by the instrument.
Functional principle - in-
terface measurement

13
3 Product description
VEGAFLEX 81 • 4 … 20 mA/HART two-wire
41824-EN-130612
TS
d1
h1
h2
d2
1
L2
L1
L3
Fig. 6: Interface measurement
1 Sensorreferenceplane(sealsurfaceoftheprocesstting)
d1 Distance to the interface (HART value 1)
d2 Distance to the level (HART value 3)
TS Thickness of the upper medium (d1 - d2)
h1 Height - Interface
h2 Height - Level
L1 Lower medium
L2 Upper medium
L3 Gas phase
Upper medium (L2)
• The upper medium must not be conductive
• The dielectric constant of the upper medium or the actual distance
to the interface must be known (input required). Min. dielectric con-
stant: 1.6. You can nd a list of dielectric constants on our home
page: www.vega.com.
• The composition of the upper medium must be stable, no varying
products or mixtures
• The upper medium must be homogeneous, no stratications
within the medium
• Min. thickness of the upper medium 50 mm (1.97 in)
• Clear separation from the lower medium, emulsion phase or detri-
tus layer max. 50 mm (1.97 in)
• If possible, no foam on the surface
Lower medium (L1)
• The dielectric constant must be 10 higher than the dielectric
constant of the upper medium, preferably electrically conductive.
Example: upper medium dielectric constant 2, lower medium at
least dielectric constant 12.
Gas phase (L3)
• Air or gas mixture
• Gas phase - dependent on the application, gas pahse does not
always exist (d2 = 0)
Prerequisites for inter-
face measurement

14
3 Product description
VEGAFLEX 81 • 4 … 20 mA/HART two-wire
41824-EN-130612
The instrument is always preset to the application "Level measure-
ment".
For the interface measurement, you can select the requested output
signal with the setup.
3.3 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 under 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 %
3.4 Accessories and replacement parts
The display and adjustment module PLICSCOM is used for measured
value indication, adjustment and diagnosis. It can be inserted into the
sensor or the external display and adjustment unit and removed at
any time.
You can nd further information in the operating instructions "Display
and adjustment module PLICSCOM" (Document-ID 27835).
The interface adapter VEGACONNECT enables the connection of
communication-capable instruments to the USB interface of a PC. For
parameter adjustment of these instruments, the adjustment software
PACTware with VEGA-DTM is required.
Output signal
Packaging
Transport
Transport inspection
Storage
Storage and transport
temperature
PLICSCOM
VEGACONNECT

15
3 Product description
VEGAFLEX 81 • 4 … 20 mA/HART two-wire
41824-EN-130612
You can nd further information in the operating instructions "Interface
adapter VEGACONNECT" (Document-ID 32628).
The VEGADIS 81 is an external display and adjustment unit for VEGA
plics®sensors.
For sensors with double chamber housing the interface adapter
"DISADAPT" is also required for VEGADIS 81.
You can nd further information in the operating instructions "VE-
GADIS 81" (Document-ID 43814).
VEGADIS 62 is suitable for measured value indication and adjustment
of sensors with HART protocol. It is looped into the 4 … 20 mA/HART
signal cable.
You can nd further information in the operating instructions "VE-
GADIS 62" (Document-ID 36469).
The PLICSMOBILE T61 is an external GSM/GPRS radio unit for
transmission of measured values and for remote parameter adjust-
ment of plics® sensors. The adjustment is carried out via PACTware/
DTM by using the integrated USB connection.
You can nd further information in the supplementary instructions
"PLICSMOBILE T61" (Document-ID 36849).
The protective cover protects the sensor housing against soiling and
intense heat from solar radiation.
You will nd additional information in the supplementary instructions
manual "Protective cover" (Document-ID 34296).
Screwed anges are available in dierent versions according to the
following standards: DIN 2501, EN 1092-1, ANSI B 16.5, JIS B 2210-
1984, GOST 12821-80.
You can nd additional information in the supplementary instructions
manual "Flanges according to DIN-EN-ASME-JIS" (Document-ID
31088).
The electronics module VEGAFLEX series 80 is a replacement part
for TDR sensors of VEGAFLEX series 80. There is a dierent version
available for each type of signal output.
You can nd further information in the operating instructions manual
"Electronics module VEGAFLEX series 80".
The display and adjustment module can be optionally replaced by a
display and adjustment module with heating function.
You can use this display and adjustment module in an ambient tem-
perature range of -40 … +70 °C.
You can nd further information in the operating instructions "Display
and adjustment module with heating" (Document-ID 31708).
VEGADIS 81
VEGADIS 62
PLICSMOBILE T61
Protective cap
Flanges
Electronics module
Display and adjustment
module with heating

16
3 Product description
VEGAFLEX 81 • 4 … 20 mA/HART two-wire
41824-EN-130612
If you are using an instrument with rod version, you can extend the
rod probe individually with curved segments and rod extensions of
dierent lengths.
All extensions used must not exceed a total length of 6 m (19.7 ft).
The extensions are available in the following lengths:
Rod: ø 12 mm (0.472 in)
• Basic segments: 20 … 5900 mm (0.79 … 232 in)
• Rod segments: 20 … 5900 mm (0.79 … 232 in)
• Curved segments: 100 x 100 mm (3.94 … 3.94 in)
You can nd further information in the operating instructions manual
"Rod extension VEGAFLEX series 80".
The combination of a bypass tube and a VEGAFLEX 81 enables con-
tinuous level measurement outside the vessel. The bypass consists
of a standpipe which is mounted as a communicating container on
the side of the vessel via two process ttings. This kind of mounting
ensures that the level in the standpipe and the level in the vessel are
the same.
The length and the process ttings can be congured individually. No
dierent connection versions available.
You can nd further information in the operating instructions manual
"Bypass tube VEGAPASS 81".
If you mount the VEGAFLEX 81 in a bypass tube or standpipe, you
have to avoid contact to the bypass tube by using a spacer at the
probe end.
You can nd additional information in the operating instructions
manual "Centering".
Rod extension
Bypass tube
Spacer

17
4 Mounting
VEGAFLEX 81 • 4 … 20 mA/HART two-wire
41824-EN-130612
4 Mounting
4.1 General instructions
On instruments with process tting thread, the hexagon must be tight-
ened with a suitable screwdriver. Wrench size see chapter "Dimen-
sions".
Warning:
The housing must not be used to screw the instrument in! Applying
tightening force can damage internal parts of the housing.
Protect your instrument further through the following measures
against moisture penetration:
• Use the recommended cable (see chapter "Connecting to power
supply")
• Tighten the cable gland
• Loop the connection cable downward in front of the cable gland
This applies particularly to:
• Outdoor mounting
• Installations in areas where high humidity is expected (e.g. through
cleaning processes)
• Installations on cooled or heated vessels
In the case of instrument housings with self-sealing NPT threads, it is
not possible to have the cable entries screwed in at the factory. The
openings for the cable glands are therefore covered with red protec-
tive caps as transport protection.
Prior to setup you have to replace these protective caps with ap-
proved cable glands or close the openings with suitable blind plugs.
The suitable cable glands and blind plugs come with the instrument.
Make sure 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 are particularly:
• Process pressure
• Process temperature
• Chemical properties of the medium
• Abrasion and mechanical inuences
You can nd the specications of the process conditions in chapter
"Technical data" as well as on the nameplate.
4.2 Mounting instructions
Mount VEGAFLEX 81 in such a way that the distance to vessel instal-
lations or to the vessel wall is at least 300 mm (12 in). In non-metallic
Screwing in
Protection against mois-
ture
Protective caps
Suitability for the process
conditions
Installation position

18
4 Mounting
VEGAFLEX 81 • 4 … 20 mA/HART two-wire
41824-EN-130612
vessels, the distance to the vessel wall should be at least 500 mm
(19.7 in).
During operation, the probe must not touch any installations or the
vessel wall. If necessary, fasten the probe end.
In vessels with conical bottom it can be advantageous to mount the
sensor in the center of the vessel, as measurement is then possible
nearly down to the lowest point of the bottom. Keep in mind that
measurement all the way down to the tip of the probe may not be pos-
sible. The exact value of the min. distance (lower dead band) is stated
in chapter "Technical data".
Fig. 7: Vessel with conical bottom
Plastic vessel/Glass vessel
The guided microwave principle requires a metal surface on the pro-
cess tting. Therefore use in plastic vessels etc. an instrument version
with ange (from DN 50) or place a metal sheet (ø > 200 mm/8 in)
beneath the process tting when screwing it in.
Make sure that the plate has direct contact with the process tting.
When installing rod or cable probes in vessels without metal walls,
e.g. in plastic vessels, the measured value can be inuenced by
strong electromagnetic elds (emitted interference according to
EN 61326: class A). In this case, use a probe with coaxial version.
Type of vessel

19
4 Mounting
VEGAFLEX 81 • 4 … 20 mA/HART two-wire
41824-EN-130612
1 2
Fig. 8: Installation in non-metallic vessel
1 Flange
2 Metal sheet
If possible, avoid sockets. Mount the sensor ush with the vessel top.
If this is not possible, use short sockets with small diameter.
Higher sockets or sockets with a bigger diameter can generally be
used. They can, however, increase the upper blocking distance (dead
band). Check if this is relevant for your measurement.
In such cases, always carry out a false signal suppression after instal-
lation. You can nd further information under "Setup procedure".
h
d
dh
DN40 ... DN150
> DN150 ... DN200
150
100
_
<
_
<
Fig. 9: Mounting socket
When welding the socket, make sure that the socket is ush with the
vessel top.
Socket

20
4 Mounting
VEGAFLEX 81 • 4 … 20 mA/HART two-wire
41824-EN-130612
1 2
Fig.10:Socketmustbeinstalledush
1 Unfavourable installation
2 Socketush-optimuminstallation
Before beginning the welding work, remove the electronics module
from the sensor. By doing this, you avoid damage to the electronics
through inductive coupling.
Do not mount the instruments in or above the lling stream. Make sure
that you detect the product surface, not the inowing product.
Fig.11:Mountingofthesensorwithinowingmedium
The reference plane for the measuring range of the sensors is the
sealing surface of the thread or ange.
Keep in mind that a min. distance must be maintained below the refer-
ence plane and possibly also at the end of the probe - measurement
in these areas is not possible (dead band). The length of the cable
can be used all the way to the end only when measuring conductive
Welding work
Inowingmedium
Measuring range