Siemens SITRANS LG250 User manual

Operating Instructions • 01/2020
Guided Wave Radar
SITRANS LG250
Probus PA
Rod and cable probe

2PBD-51041053
SITRANS LG250 - Operating Instructions
44570-EN-200221

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PBD-51041053 SITRANS LG250 - Operating Instructions
44570-EN-20022144570-EN-200221
Contents
1 About this document ............................................................................................................... 5
1.1 Function ........................................................................................................................... 5
1.2 Target group ..................................................................................................................... 5
1.3 Symbols used................................................................................................................... 5
2 For your safety ......................................................................................................................... 6
2.1 Authorised personnel ....................................................................................................... 6
2.2 Appropriate use................................................................................................................ 6
2.3 Warning about incorrect use............................................................................................. 6
2.4 General safety instructions............................................................................................... 6
2.5 EU conformity................................................................................................................... 7
2.6 NAMUR recommendations .............................................................................................. 7
2.7 Installation and operation in the USA and Canada ........................................................... 7
3 Product description ................................................................................................................. 8
3.1 Conguration.................................................................................................................... 8
3.2 Principle of operation........................................................................................................ 9
3.3 Packaging, transport and storage................................................................................... 11
3.4 Accessories.................................................................................................................... 12
4 Mounting................................................................................................................................. 13
4.1 General instructions ....................................................................................................... 13
4.2 Mounting instructions ..................................................................................................... 14
5 Connecting to power supply................................................................................................. 22
5.1 Preparing the connection ............................................................................................... 22
5.2 Connecting..................................................................................................................... 23
5.3 Wiring plan, single chamber housing.............................................................................. 24
5.4 Wiring plan, double chamber housing ............................................................................ 24
5.5 Set instrument address .................................................................................................. 25
5.6 Switch-on phase............................................................................................................. 26
6 Set up with the display and adjustment module ................................................................ 27
6.1 Insert display and adjustment module............................................................................ 27
6.2 Adjustment system......................................................................................................... 28
6.3 Parameter adjustment - Quick setup .............................................................................. 29
6.4 Parameter adjustment - Extended adjustment................................................................ 29
6.5 Saving the parameterisation data................................................................................... 48
7 Setup with PACTware............................................................................................................. 49
7.1 Connect the PC.............................................................................................................. 49
7.2 Parameter adjustment with PACTware............................................................................ 49
7.3 Set up with the quick setup............................................................................................. 50
7.4 Saving the parameterisation data................................................................................... 52
8 Set up with other systems .................................................................................................... 53
8.1 DD adjustment programs ............................................................................................... 53
9 Diagnostics and servicing .................................................................................................... 54
9.1 Maintenance .................................................................................................................. 54
9.2 Diagnosis memory ......................................................................................................... 54
9.3 Status messages............................................................................................................ 55
9.4 Rectify faults................................................................................................................... 58

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9.5 Exchanging the electronics module................................................................................ 63
9.6 Exchanging the cable/rod............................................................................................... 63
9.7 Software update ............................................................................................................. 65
9.8 How to proceed if a repair is necessary.......................................................................... 66
10 Dismount................................................................................................................................. 67
10.1 Dismounting steps.......................................................................................................... 67
10.2 Disposal ......................................................................................................................... 67
11 Supplement ............................................................................................................................ 68
11.1 Technical data ................................................................................................................ 68
11.2 DevicecommunicationProbusPA................................................................................ 80
11.3 Dimensions .................................................................................................................... 84
11.4 Trademark ...................................................................................................................... 89
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: 2020-01-24

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PBD-51041053 SITRANS LG250 - Operating Instructions
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1 About this document
1.1 Function
This instruction provides all the information you need for mounting,
connection and setup as well as important instructions for mainte-
nance,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
Information, note, tip: This symbol indicates helpful additional infor-
mation and tips for successful work.
Note: This symbol indicates notes to prevent failures, malfunctions,
damage to devices or plants.
Caution: Non-observance of the information marked with this symbol
may result in personal injury.
Warning: Non-observance of the information marked with this symbol
may result in serious or fatal personal injury.
Danger: Non-observance of the information marked with this symbol
results in serious or fatal personal injury.
Ex applications
This symbol indicates special instructions for Ex applications.
• List
The dot set in front indicates a list with no implied sequence.
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.

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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
SITRANS LG250 is a sensor for continuous 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.
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.

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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.
The EU conformity declaration can be found on our homepage.
Electromagnetic compatibility
Instruments in four-wire or Ex-d-ia version are designed for use in an
industrial environment. Nevertheless, electromagnetic interference
from electrical conductors and radiated emissions must be taken into
account, as is usual with class A instruments according to EN 61326-
1.Iftheinstrumentisusedinadierentenvironment,theelectromag-
netic 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lstherequirementsofthefollowingNAMURrecom-
mendations:
• NE 21 – Electromagnetic compatibility of equipment
• 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.

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3 Product description
3.1 Conguration
The scope of delivery encompasses:
• Sensor SITRANS LG250
• Optional accessory
The further scope of delivery encompasses:
• Documentation
– Operating instructions SITRANS LG250
– 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 1.3.0
• OnlyforinstrumentversionswithoutSILqualication
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

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2
1
5
3
6
4
7
8
11
12
13
14
10
9
1
Fig. 1: Layout of the type label (example)
1 Instrument type
2 Product code
3 Process and ambient temperature
4 Process pressure
5 Signal output electronics
6 Voltage supply
7 Protection rating
8 Order number
9 Identicationcode
10 Serial number of the instrument
11 Symbol of the device protection class
12 Reminder to observe the instrument documentation
13 ID numbers, instrument documentation
14 Hardware and software version
3.2 Principle of operation
The SITRANS LG250 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
as level.
Application area
Functional principle -
level measurement

10 PBD-51041053
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d
h
1
Fig. 2: Level measurement
1 Sensorreferenceplane(sealsurfaceoftheprocesstting)
d Distance to the level
h Height - Level
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.
TS
d1
h1
h2
d2
1
L2
L1
L3
Fig. 3: Interface measurement
1 Sensorreferenceplane(sealsurfaceoftheprocesstting)
d1 Distance to the interface
d2 Distance to the level
TS Thickness of the upper medium (d1 - d2)
h1 Height - Interface
h2 Height - Level
L1 Lower medium
L2 Upper medium
L3 Gas phase
Functional principle - in-
terface measurement

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PBD-51041053 SITRANS LG250 - Operating Instructions
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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.siemens.com/sitranslg.
• 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 phase does not
always exist (d2 = 0)
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 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.
Prerequisites for inter-
face measurement
Output signal
Packaging
Transport
Transport inspection
Storage

12 PBD-51041053
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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.
3.4 Accessories
The instructions for the listed accessories can be found in the down-
load area on our homepage.
The display and adjustment module LG Local Display Interface is
used for measured value indication, adjustment and diagnosis.
The LG Remote Interface is an external display and adjustment unit
for sensors with single chamber housing and Ex d double chamber
housing.
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.
If you are using an instrument in rod version, you can extend the rod
probe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)
If you mount the SITRANS LG250 in a bypass tube or standpipe, you
have to avoid contact to the bypass tube by using a spacer at the
probe end.
Storage and transport
temperature
Lifting and carrying
Display and adjustment
module
External display and
adjustment unit
Flanges
Rod components
Centering

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PBD-51041053 SITRANS LG250 - Operating Instructions
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4 Mounting
4.1 General instructions
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! Depending on the device version, tightening can cause dam-
age, e. g. to the rotation mechanism of the housing.
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thedegreeofcontaminationspeciedinchapter
"Technical data" meets the existing ambient conditions.
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.
Metric threads
In the case of instrument housings with metric thread, the cable
glands are screwed in at the factory.They are sealed with plastic
plugs as transport protection.
You have to remove these plugs before electrical connection.
NPT thread
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
free openings for the cable glands are therefore covered with red dust
protection caps as transport protection.The dust protection caps do
notprovidesucientprotectionagainstmoisture.
Prior to setup you have to replace these protective caps with ap-
proved cable glands or close the openings with suitable blind plugs.
Note:
For safety reasons, the instrument must only be operated within the
permissibleprocessconditions.Youcannddetailedinformationon
Screwing in
Protection against mois-
ture
Cable glands
Process conditions

14 PBD-51041053
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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
4.2 Mounting instructions
Mount SITRANS LG250 in such a way that the distance to vessel
installations or to the vessel wall is at least 300 mm (12 in). In non-
metallic 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zone)isstated
in chapter "Technical data" of the operating instructions.
Fig. 4: Vessel with conical bottom
Plastic vessel/Glass vessel
The guided microwave principle requires a metallic surface on the
processtting.Therefore,inplasticvessels,etc.,useaninstru-
ment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 mounting rod or cable probes in vessels without metal walls,
e.g.inplasticvessels,themeasuredvaluecanbeinuencedby
Installation position
Type of vessel

15
PBD-51041053 SITRANS LG250 - Operating Instructions
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strongelectromagneticelds(emittedinterferenceaccordingto
EN 61326: class A). In this case, use a probe with coaxial version.
1 2
Fig. 5: Mounting 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deadzone.Checkifthis
is relevant for your measurement.
In such cases, always carry out a false signal suppression after
mounting.Youcanndfurtherinformationunder"Setup procedure".
h
d
dh
DN25 ... DN150
> DN150 ... DN200
≤ 150 mm (5.91")
≤ 100 mm (3.94")
Fig. 6: Mounting socket
Whenweldingthesocket,makesurethatthesocketisushwiththe
vessel top.
Mounting socket

16 PBD-51041053
SITRANS LG250 - Operating Instructions
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1 2
Fig.7:Socketmustbeinstalledush
1 Unfavourable mounting
2 Socketush-optimummounting
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mediumsurface,nottheinowingproduct.
Fig.8: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zone).Thelengthofthecable
can be used all the way to the end only when measuring conductive
products.Thesedeadzonesfordierentmediumsarelistedinchap-
ter "Technical data". Keep in mind for the adjustment that the default
setting for the measuring range refers to water.
Welding work
Inowingmedium
Measuring range

17
PBD-51041053 SITRANS LG250 - Operating Instructions
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Theprocessttingmustbesealedifthereisgaugeorlowpressurein
the vessel. Before use, check if the seal material is resistant against
the measured product and the process temperature.
Themax.permissiblepressureisspeciedinchapter"Technical
data" or on the type label of the sensor.
Standpipes or bypass tubes are normally metal tubes with a diameter
of 30 … 200 mm (1.18 … 7.87 in). Up to a diameter of 80 mm (3.15
in) such a tube corresponds to a coax measuring probe. Lateral inlets
inbypasstubesdonotinuencethemeasurement.
Measuring probes can be mounted in bypass tubes up to DN 200.
Forbypasstubes,selecttheprobelengthsuchthatthedeadzone
oftheprobeisaboveandbelowthelowerlateralllingopeningsof
the bypass tube.You can thus measure the complete range of the
medium in the bypass tube (h).When designing the bypass tube,
keepthedeadzoneoftheprobeinmindandselectthelengthofthe
bypasstubeabovetheupperlateralllingopeningaccordingly.
Microwaves can penetrate many plastics.This is why plastic tubes are
problematic for measurement applications. If durability is no problem,
we recommend the use of uncoated metal standpipes.
When the SITRANS LG250 is used in bypass tubes, contact with the
tube wall must be avoided. We recommend for this purpose a cable
probe with centering weight.
Caution:
When mounting, make sure that the cable is straight over its entire
length. A kink in the cable can cause measurement errors and contact
with the tube.
With rod probes, a spacer is generally not required. However, if there
is a risk of the rod probe being pressed against the tube wall by in-
owingmedium,youshouldmountaspacerattheprobeendtoavoid
contact with the tube wall. In the case of cable probes, the cable can
be strained.
Keepinmindthatthelowerdeadzoneunderneaththespacerin-
creases if spacers are used.
Buildupcanformonthespacers.Strongbuildupcaninuencethe
measurement.
Pressure
Bypass tubes

18 PBD-51041053
SITRANS LG250 - Operating Instructions
44570-EN-200221
1
2 3
h
Fig. 9: Mounting in a bypass tube - Position of the spacer or the centering weight
1 Rod probe with spacer (PEEK)
2 Cable probe with centering weight
3 Spacer (PEEK) on the gravity weight of a cable probe
h Measurable tube section
Note:
Measurement in a standpipe is not recommended for extremely adhe-
sive products. In case of slight buildup, you should choose a bypass
tube with bigger diameter.
Instructions for the measurement:
• The 100 % point in bypass tubes should be below the upper tube
connection to the vessel.
• The 0 % point in bypass tubes should be above the lower tube
connection to the vessel.
• A false signal suppression with installed sensor is generally rec-
ommended to achieve the best possible accuracy.
Standpipes or surge pipes are normally metal tubes with a diameter
of 30 … 200 mm (1.18 … 7.87 in). Up to a diameter of 80 mm (3.15
in), such a pipe corresponds to a coax measuring probe. It does not
matter if the standpipe is perforated or slotted for better mixing.
Measuring probes can be mounted in standpipes up to DN 200.
Standpipes

19
PBD-51041053 SITRANS LG250 - Operating Instructions
44570-EN-200221
≥ 10 mm
(0.39")
≥ 10 mm
(0.39")
ø 30 ... 200 mm
(1.18 ... 7.87")
ø 30 ... 200 mm
(1.18 ... 7.87")
h
1
2
AB
3
Fig. 10: Mounting in a standpipe
1 Holes (for mixing)
2 Standpipe - vertically mounted - max. deviation 10 mm (0.4 in)
3 Ventilation opening
A Rod probe with spacer (steel)
B Cable probe with centering weight
h Measuring range
For standpipes, select the probe length such that the upper dead
zoneoftheprobeisabovetheupperventilationhole.Thisallowsyou
to measure the total level range of the medium in the standpipe.When
designingthestandpipe,keeptheupperdeadzoneoftheprobein
mindandplanthelengthabovetheupperlateralllingopeningac-
cordingly.
Microwaves can penetrate many plastics.This is why plastic tubes are
problematic for measurement applications. If durability is no problem,
we recommend the use of uncoated metal standpipes.
When the SITRANS LG250 is used in standpipes, contact with the
tube wall must be avoided. We recommend for this purpose a cable
probe with centering weight.
Caution:
When mounting, make sure that the cable is straight over its entire
length. A kink in the cable can cause measurement errors and contact
with the tube.
With rod probes, a spacer is generally not required. However, if there
is a risk of the rod probe being pressed against the tube wall by in-
owingmedium,youshouldmountaspacerattheprobeendtoavoid
contact with the tube wall. In the case of cable probes, the cable can
be strained.

20 PBD-51041053
SITRANS LG250 - Operating Instructions
44570-EN-200221
Keepinmindthatthelowerdeadzoneunderneaththespacerin-
creases if spacers are used.
Buildupcanformonthespacers.Strongbuildupcaninuencethe
measurement.
Note:
Measurement in a standpipe is not recommended for extremely
adhesive products. In case of slight buildup, you should choose a
standpipe with bigger diameter.
Instructions for the measurement:
• The 100 % point with standpipes should be below the upper
ventilation hole.
• The 0 % point in standpipes should be above the gravity or center-
ing weight.
• A false signal suppression with installed sensor is generally rec-
ommended to achieve the best possible accuracy.
If there is a risk of the cable probe touching the vessel wall during
operation due to product movements or agitators, etc., the measuring
probeshouldbesecurelyxed.
There is an internal thread (M8) in the gravity weight, e.g. for an eye-
bolt (optional).
Make sure that the probe cable is not completely taut. Avoid tensile
loads on the cable.
Avoidundenedvesselconnections,i.e.theconnectionmustbe
eithergroundedreliablyorisolatedreliably.Anyundenedchangeof
this condition can lead to measurement errors.
If there is a danger of the rod probe touching the vessel wall, fasten
the probe at the bottom end.
Keep in mind that measurement is not possible below the fastening
point.
1
2
1
2
Fig. 11: Fasten the probe
1 Measuring probe
2 Retaining sleeve
If there is a risk of the cable probe touching the vessel wall during
operation due to product movements or agitators, etc., the measuring
probe can be strained.
For this purpose there is an internal thread (M12 or M8) in the gravity
weight.
Fasten
Fixing facility