Siemens Sitrans LR250 User manual

Instruction Manual July 2007
LR250 (HART)
sitrans

北京迪妙声科技有限公司
BEJING DELLSONICS SCIENCE & TECHNOLOGY LTD.
地址：北京海淀区魏公村街 1 号韦伯豪家园 3-3-702 (100081) http://www.dellsonics.com
DELLSONIC
S
公 司 简 介
北京迪妙声科技有限公司（原名北京妙声力科技有限公司），位于北京市海淀区中关村
南大街，是与西门子公司德国总部正式签约的西门子过程仪表及分析仪器核心合作伙伴，
也是西门子北方区域规模最大、实力最强的优秀代理商。
公司主营：
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作为西门子公司长期稳定的代理商，我公司有着 10 余年产品的销售和服务经验，无论
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Table of Contents
Table of Contents
Table of Contents ...............................................................................................................i
Safety Notes ...........................................................................................................................................1
Safety marking symbols ............................................................................................................1
FCC Conformity ......................................................................................................................................1
The Manual ............................................................................................................................................2
Technical Support .................................................................................................................................2
SITRANS LR250 Overview ................................................................................................4
Specifications ....................................................................................................................5
Power............................................................................................................................................. 5
Performance................................................................................................................................. 5
Interface ........................................................................................................................................ 6
Mechanical................................................................................................................................... 6
Environmental .............................................................................................................................. 7
Process.......................................................................................................................................... 8
Approvals ...................................................................................................................................... 8
Programmer (infrared keypad) ................................................................................................ 9
Dimensions ...........................................................................................................................................10
Threaded Horn Antenna with extension .............................................................................10
Flanged Horn ..............................................................................................................................11
Flat Face Flange ........................................................................................................................12
Installation ........................................................................................................................15
Mounting location ...............................................................................................................................16
Nozzle design .............................................................................................................................16
Nozzle location ..........................................................................................................................16
Orientation in a vessel with obstructions ............................................................................17
Mounting on a Stillpipe or Bypass Pipe ..............................................................................18
Installation Instructions .....................................................................................................................19
Wiring ................................................................................................................................20
Power .....................................................................................................................................................20
Connecting SITRANS LR250 .............................................................................................................20
Wiring setups for hazardous area installations ..........................................................................22
Intrinsically Safe wiring........................................................................................................... 22
Non-incendive wiring (only for USA/Canada) ....................................................................24
FM/CSA Intrinsically Safe connection drawing (North America only) ..................................25
FM/CSA Non-incendive connection drawing (North America only) ......................................26
Instructions specific to hazardous area installations ................................................................27
Quick Start via local operation .....................................................................................28
Activating SITRANS LR250 ...............................................................................................................28
The LCD Display ........................................................................................................................28
Handheld Programmer (Part No. 7ML1930-1BK) ..............................................................30
Programming SITRANS LR250 ...............................................................................................31
Quick Start Wizard via the handheld programmer .....................................................................34
Level application example ................................................................................................................36
Auto False Echo Suppression ..........................................................................................................36

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Table of Cont ents
Operating via SIMATIC PDM .........................................................................................37
Functions in SIMATIC PDM ..............................................................................................................37
Device Description (DD) ..........................................................................................................37
Configuring a new device .......................................................................................................38
Quick Start Wizard via SIMATIC PDM ..........................................................................................38
Using Linearization via the Quick Start wizard ..................................................................42
Configuring a stillpipe application .........................................................................................45
Calibrating LR250 via PDM ......................................................................................................45
Changing parameter settings using SIMATIC PDM .........................................................46
Parameters accessed via pull-down menus ......................................................................46
Parameter Reference .....................................................................................................53
Pull-down menus via SIMATIC PDM ...................................................................................53
Quick Start Wizard ..............................................................................................................................53
Quick Start ............................................................................................................................................ 54
Setup ......................................................................................................................................................55
Device .......................................................................................................................................... 55
Input ..............................................................................................................................................56
Output ...........................................................................................................................................72
Fail-safe .......................................................................................................................................75
Diagnostics ...........................................................................................................................................76
Echo Profile ................................................................................................................................76
Measured Values...................................................................................................................... 76
Remaining Device Lifetime .....................................................................................................77
Remaining Sensor Lifetime .....................................................................................................79
Service ...................................................................................................................................................81
Device Reset .............................................................................................................................. 81
Manufacture Date .....................................................................................................................81
LCD Fast Mode ..........................................................................................................................81
LCD Contrast ..............................................................................................................................82
Powered Hours ..........................................................................................................................82
Power-on Resets....................................................................................................................... 82
Memory Test .............................................................................................................................. 82
Service Interval.......................................................................................................................... 82
Calibration Interval ...................................................................................................................84
Communication ....................................................................................................................................86
Device Address ......................................................................................................................... 86
Communication Control ...........................................................................................................86
Security .................................................................................................................................................87
Lock .............................................................................................................................................. 87
Unlock value ...............................................................................................................................87
Language ..............................................................................................................................................87
Appendix A: Alphabetical Parameter List ..................................................................89
Appendix B: Troubleshooting .......................................................................................92
Communication Troubleshooting ....................................................................................................92
Generally: ....................................................................................................................................92
Specifically: .................................................................................................................................92
Device Status Icons ...........................................................................................................................93
General Fault Codes ...........................................................................................................................94
Operation Troubleshooting ...............................................................................................................99

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Table of Contents
Appendix C: Maintenance ...........................................................................................102
Unit Repair and Excluded Liability ................................................................................................102
Appendix D: Technical Reference .............................................................................103
Principles of Operation ....................................................................................................................103
Echo Processing ...............................................................................................................................103
Process Intelligence ...............................................................................................................103
Time Varying Threshold (TVT) Curves ...............................................................................104
Echo Lock ..................................................................................................................................104
Echo Position Detection ........................................................................................................105
Auto False Echo Suppression ..............................................................................................105
Measurement Range .......................................................................................................................106
Near Range ..............................................................................................................................106
Far Range ..................................................................................................................................106
Measurement Response .................................................................................................................106
mA Output ...........................................................................................................................................107
Damping ..............................................................................................................................................107
Loss of Echo (LOE) ............................................................................................................................108
Fail-safe Mode ...................................................................................................................................108
Fail-safe Timer .........................................................................................................................108
Fail-safe value ..........................................................................................................................108
Maximum Process Temperature Chart .......................................................................................109
Process Pressure/Temperature derating curves .....................................................................110
Horn Antenna or Wave Guide ..............................................................................................111
Loop power .........................................................................................................................................114
Typical Connection Drawing ................................................................................................114
Allowable operating area of SITRANS LR250 ..................................................................114
Startup Behavior .....................................................................................................................115
Appendix E: Application Examples ............................................................................116
Liquid resin in storage vessel, level measurement ........................................................116
Horizontal vessel with volume measurement ..................................................................118
Application with Stillpipe .......................................................................................................120
Appendix F: HART Communications .........................................................................122
SIMATIC PDM ...................................................................................................................................122
HART Device Description (DD) ......................................................................................................122
HART Communicator 375 Menu Structure .................................................................................123
Supported HART Commands .........................................................................................................126
Universal and Common Practice Commands ..................................................................126
Device Specific Commands ..................................................................................................126
Appendix G: Software Revision History ....................................................................127
Glossary ..........................................................................................................................129
Index ................................................................................................................................133
LCD menu structure ......................................................................................................137

7ML19985JE01 SITRANS LR250 (HART) – INSTRUCTION MANUAL Page 1
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SITRANS LR250
Safety Notes
Special attention must be paid to warnings and notes highlighted from the rest of the text
by grey boxes.1
Safety marking symbols
FCC Conformity
US Installations only: Federal Communications Commission (FCC) rules
WARNING: relates to a caution symbol on the product, and means
that failure to observe the necessary precautions can result in death,
serious injury, and/or considerable material damage.
WARNING1: means that failure to observe the necessary
precautions can result in death, serious injury, and/or considerable
material damage.
Note: means important information about the product or that part of the operating
manual.
1. This symbol is used when there is no corresponding caution symbol on the product.
In manual On product Description
Earth (ground) Terminal
Protective Conductor Terminal
(Label on product: yellow background.) WARNING: refer
to accompanying documents (manual) for details.
WARNING: Changes or modifications not expressly approved by
Siemens Milltronics could void the user’s authority to operate the
equipment.
Notes:
• This equipment has been tested and found to comply with the limits for a Class A
digital device, pursuant to Part 15 of the FCC Rules. These limits are designed to
provide reasonable protection against harmful interference when the equipment is
operated in a commercial environment.
• This equipment generates, uses, and can radiate radio frequency energy and, if not
installed and used in accordance with the instruction manual, may cause harmful
interference to radio communications. Operation of this equipment in a residential
area is likely to cause harmful interference to radio communications, in which case
the user will be required to correct the interference at his own expense.

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SITRANS LR250
Abbreviations and Identifications
Short form Long Form Description Units
A/D Analog to digital
CE / FM / CSA Conformité Européenne / Factory Mutual /
Canadian Standards Association safety approval
CiInternal capacitance F
D/A Digital to analog
DAC Digital Analog Converter
DCS Distributed Control System control room
apparatus
dK dielectric constant
FV Full Vacuum
ESD Electrostatic Discharge
HART Highway Addressable Remote Transducer
IiInput current mA
IoOutput current mA
IS Intrinsically Safe safety approval
LiInternal inductance mH
mH milliHenry 10-3 H
µFmicroFarad 10-6 F
µsmicrosecond 10
-6 s
PED Pressure Equipment Directive safety approval
pF pico Farads 10-12 F
ppm parts per million
PV Primary Variable measured value
SV Secondary Variable equivalent value
TVT Time Varying Threshold sensitivity
threshold
UiInput voltage V
UoOutput voltage V

Page 4 SITRANS LR250 (HART) – INSTRUCTION MANUAL 7ML19985JE01
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SITRANS LR250
SITRANS LR250 Overview
SITRANS LR250 is a 2-wire 25 GHz pulse radar level transmitter for continuous monitoring
of liquids and slurries in storage vessels including high pressure and high temperature, to
a range of 20 m. (66ft). It is ideal for small vessels and low dielectric media
The instrument consists of an electronic component coupled to a horn antenna and either
a threaded or flange type process connection.
SITRANS LR250 supports HART1communication protocol, and SIMATIC PDM software.
Signals are processed using Process Intelligence which has been field-proven in over
500,000 applications worldwide (ultrasonic and radar).
Programming
SITRANS LR250 is very easy to install and configure via a graphical local user interface
(LUI). You can modify the built in parameters either locally via the Siemens infrared hand-
held programmer, or from a remote location via SIMATIC PDM.
Applications
• liquids and slurries
• bulk storage vessels
• simple process vessels
Approvals and Certificates
SITRANS LR250 is available with General Purpose approval, or for hazardous areas. For
details see
Approvals on page 8.
1. HART® is a registered trademark of the HART Communication Foundation

7ML19985JE01 SITRANS LR250 (HART) – INSTRUCTION MANUAL Page 5
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Specifications
Specifications
Power
• Maximum 30 V DC
• 4 to 20 mA
• Max startup current see
Startup Behavior on page 115
Performance
Reference operating conditions according to IEC 60770-1
• ambient temperature +15 to +25 °C (+59 to +77 °F)
• humidity 45% to 75% relative humidity
• ambient pressure 860 to 1060 mbar g (86000 to 106000 N/m2 g)
Measurement Accuracy (measured in accordance with IEC 60770-1)
• Maximum measured error = 5 mm (0.2") (including hysteresis and non-
repeatability)
Frequency K-band
Max. measurement range 20 m (65.6 ft) except for 1.5" horn which has 10 m
(32.8 ft)
Min. measurement range150 mm (1.97") from end of horn
Note: Siemens Milltronics makes every attempt to ensure the accuracy of these
specifications but reserves the right to change them at any time.
Nominal 24 V DC with
max. 550 Ohm loop resis-
tance:
For other configurations, see the chart under Loop
power
on page 114
1. Minimum range is horn length + 50 mm. See
Dimensions on page 10 and Flanged Horn on page
11.

Page 6 SITRANS LR250 (HART) – INSTRUCTION MANUAL 7ML19985JE01
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Specifications
Update time minimum 1 second, depending on parameter settings
Influence of ambient temperature < 0.003%/K (average over full temperature range,
referenced to maximum range)
Dielectric constant of material measured
• Minimum dK = 1.6 (depending on antenna and application type)
Memory:
• non-volatile EEPROM
• no battery required.
Interface
Analog output
• signal range 4 to 20 mA (±0.02 mA accuracy)
upper limit 20 to 23 mA adjustable
• fail signal 3.6 mA to 23 mA; or last value
• load Max. 600 Ω; for HART1communication min. 230 Ω
Communication: HART
• Load 230 to 600 Ω, 230 to 500 Ω when connecting a coupling
module
• Max. Line Length multi-wire: ≤1500 m (4921 ft)
• Protocol HART, Version 5.1
Configuration Siemens SIMATIC PDM (PC), or
Siemens Milltronics infrared hand-held programmer, or
HART handheld communicator
Display (local)2graphic LCD, with bar graph representing level
Mechanical
Process Connections:
• threaded connection 1.5” or 2" NPT (ASME 1.20.1), BSPT (EN 10226-1) or
G (BS EN ISO 228-1)
• flange connection 2", 3", 4" (ANSI 150, 300#), 50, 80, 100 mm (PN16, 40,
JIS 10K)
• materials 316 L stainless steel, optional Alloy N06022/2.4602 (C-22)
1. HART® is a registered trademark of HART Communication Foundation.
2. Display quality will be degraded in temperatures below –25 °C (–13 °F) and above +65 °C (+149 °F).

7ML19985JE01 SITRANS LR250 (HART) – INSTRUCTION MANUAL Page 7
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Specifications
Antenna:
• horn standard 1.5" (40mm), 2" (50 mm), 3" (80 mm), and
4" (100 mm) horn, optional 100 mm (4") horn extension
• materials 316L stainless steel with PTFE emitter
optional Alloy N06022/2.4602 (C-22) with PTFE emitter
Enclosure
• construction aluminum, polyester powder-coated
• conduit entry 2 x M20x1.5, or 2 x ½" NPT
• ingress protection Type 4X/NEMA 4X, Type 6/NEMA 6, IP 67, IP68 (see note
below)
Weight
• standard model < 3 kg (6.6 lb) 37.5 mm (1.5") threaded connection with horn
antenna
Environmental
• location indoor/ outdoor
• altitude 5000 m (16,404 ft) max.
• ambient temperature −40 to +80 °C (−40 to +176 °F)
• relative humidity suitable for outdoor
Type 4X/NEMA 4X, Type 6/NEMA 6, IP67, IP68 enclosure
(see note below)
• installation category I
• pollution degree 4
Notes:
• Check Approvals on page 8, for the specific configuration you are about to use or
install.
• Use appropriate conduit seals to maintain IP or NEMA rating.

Page 8 SITRANS LR250 (HART) – INSTRUCTION MANUAL 7ML19985JE01
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Specifications
Process
•temperature
1−40 to 150 °C (−40 to 302 °F)
(at process connection
with FKM O-ring)
• pressure (vessel)1Refer to
Process Pressure/Temperature derating curves on
page 110.
Approvals
• General CSAUS/C, FM, CE
• Radio Europe (R&TTE), FCC, Industry Canada
• Hazardous Intrinsically Safe (Europe) ATEX II 1G, EEx ia IIC T4
ATEX II 1D, EEx tD A20 IP67 T90 °C
(International) IECEx SIR 05.0031X, Ex ia IIC T4,
EX tD A20 IP67 T90 °C
(US/Canada) FM/CSA: (barrier required)2
Class I, Div. 1, Groups A, B, C, D
Class II, Div. 1, Groups E, F, G
Class III T4
Non-incendive (US/Canada) FM/CSA3Class I, Div. 2,
Groups A, B, C, D T5
1. The specifications apply to the standard horn only. The maximum temperature is dependent on
the process connection, antenna materials, and vessel pressure. For more detail, or for other
configurations, see
Maximum Process Temperature Chart on page 109, and Process Pressure/
Temperature derating curves
on page 110.
Note: The device nameplate lists the approvals that apply to your device.
2. See
FM/CSA Intrinsically Safe connection drawing (North America only) on page 25 for drawing
number 23650653.
3. See
FM/CSA Non-incendive connection drawing (North America only) on page 26 for drawing
number 23650673.

Page 12 SITRANS LR250 (HART) – INSTRUCTION MANUAL 7ML19985JE01
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Specifications
Flat Face Flange
Flange markings
The flange markings located around the outside edge of the flat-face flange identify the
flange assembly on which the device is mounted. The flat-face flange identification is
followed by identification of the welded assembly.
Flat Face Flange Identification
Welded
Assembly
Identification
Serial No. Logo
Flange Series
Material Heat
Code
Flange
Series
Heat
Code
No.
Series Nominal
Size
MMDDYYXXX 25556
2 150 316L/ 1.4404
or
316L/ 1.4435
A1B2C3 25546 A1B2C3
DN 80 PN 16
“A”
VIEW “A”-"A"
“A”
process side
enclosure
mounting holes
(threaded)
bolt hole Ø
flange O.D.

7ML19985JE01 SITRANS LR250 (HART) – INSTRUCTION MANUAL Page 13
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Specifications
Serial number: a unique number allotted to each flange, including the date of
manufacture (MMDDYY) followed by a number from 001 to 999.
Flange series: the Siemens Milltronics drawing identification.
Nominal size: the flange size followed by the hole pattern for a particular flange class.
For example – a 2 inch ANSI B 16.5 150 lb class flange (North America)
or – a DN 80 EN 1092-1 PN 16 class flange (Europe).
Material: the basic flange material (AISI or EU material designation). North
American material codes are followed by /European ones. For example,
material designation 316L/1.4404.
Heat code: a flange material batch code identification.
Flange
sizea
a. A 2" flange is designed to fit a 2" pipe: for actual flange dimensions see Flange O.D.
Flange Class Flange O.D. Bolt Hole Circle Ø Bolt Hole Ø No. of Bolt
Holes
2” ANSI 150# 6.0” 4.75” 0.75” 4
3” ANSI 150# 7.5” 6.0” 0.75” 4
4” ANSI 150# 9.0” 7.50” 0.75” 8
2” ANSI 300# 6.50” 5.00” 0.75” 8
3” ANSI 300# 8.25” 6.62” 0.88” 8
4” ANSI 300# 10.00” 7.88” 0.88” 8
DN 50 EN PN 16 165 mm 125 mm 18 mm 4
DN 80 EN PN 16 200 mm 160 mm 18 mm 8
DN 100 EN PN 16 220 mm 180 mm 18 mm 8
DN 50 EN PN 40 165 mm 125 mm 18 mm 4
DN 80 EN PN 40 200 mm 160 mm 18 mm 8
DN 100 EN PN 40 235 mm 190 mm 22 mm 8
50 mm JIS 10K 155 mm 120 mm 19 mm 4
80 mm JIS 10K 185 mm 150 mm 19 mm 8
100 mm JIS 10K 210 mm 175 mm 19 mm 8

Page 14 SITRANS LR250 (HART) – INSTRUCTION MANUAL 7ML19985JE01
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Specifications
Threaded Connection Markings
Threaded connection markings are found on the flat face/faces of the process
connection.
Serial number:a unique number allotted to each flange, including the date of manufacture
(MMDDYY) followed by a number from 001 to 999.
Logo Serial Number Thread Size Thread Series
MMDDYYXXX 1.5
NPT
BSP
G/PF

7ML19985JE01 SITRANS LR250 (HART) – INSTRUCTION MANUAL Page 15
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Installation
Installation
1
WARNINGS:
• Installation shall only be performed by qualified personnel and in
accordance with local governing regulations.
• SITRANS LR250 is to be used only in the manner outlined in this manual,
otherwise protection provided by the device may be impaired.
• Never attempt to loosen, remove, or disassemble process connection
or instrument housing while vessel contents are under pressure.
• This product is designated as a Pressure Accessory per Directive
97/23/EC and is not intended for use as a safety device.
• Materials of construction are chosen based on their chemical
compatibility (or inertness) for general purposes. For exposure to
specific environments, check with chemical compatibility charts
before installing.
• The user is responsible for the selection of bolting and gasket materials
which will fall within the limits of the flange and its intended use and
which are suitable for the service conditions.
• Improper installation may result in loss of process pressure.
Notes:
• For European Union and member countries, installation must be according to ETSI
EN 302372.
• Refer to the device nameplate for approval information.
• The Process Device Tag shall remain with the process pressure boundary
assembly1. In the event the instrument package is replaced, the Process Device Tag
shall be transferred to the replacement unit.
• SITRANS LR250 units are hydrostatically tested, meeting or exceeding the
requirements of the ASME Boiler and Pressure Vessel Code and the European
Pressure Equipment Directive.
• The serial numbers stamped in each process connection body provide a unique
identification number indicating date of manufacture.
Example: MMDDYY – XXX (where MM = month, DD = day, YY = year, and
XXX= sequential unit produced
Further markings (space permitting) indicate flange configuration, size, pressure
class, material, and material heat code.
1. The process pressure boundary assembly comprises the components that act as a
barrier against pressure loss from the process vessel: that is, the combination of
process connection body and emitter, but normally excluding the electrical enclosure.

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Installation
Mounting location
Nozzle design
• The end of the horn must protrude
a minimum of 10 mm (0.4”) to avoid
false echoes being reflected from
the nozzle.
• An antenna extension:
(100 mm/3.93") is available.
Nozzle location
• Keep emission cone free of
interference from ladders,
pipes, I-beams or filling
streams.
• Make allowance for beam
width to avoid interference
with emission cone
• Avoid central locations on
tall, narrow vessels.
Notes:
• Correct location is key to a successful application.
• Avoid reflective interference from vessel walls and obstructions by following the
guidelines below
Notes:
• Beam width depends on horn size:
see below.
• For details on avoiding false echoes,
see
Auto False Echo Suppression on
page 105.
Min. clearance:
10 mm (0.4")
beam width:
1.5" horn = 19°
2" horn = 15°
3" horn = 10°
4" horn = 8°
preferred
undesirable
19°
emission
cone

7ML19985JE01 SITRANS LR250 (HART) – INSTRUCTION MANUAL Page 17
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Installation
Nozzle location (continued)
• Provide easy access for viewing the display and programming via the hand
programmer.
• Provide an environment suitable to the housing rating and materials of construction.
• Provide a sunshield if the instrument will be mounted in direct sunlight.
Orientation in a vessel with obstructions
Polarization reference point
ambient temperature –40 °C
to 80 °C (–40 °F to 176 °F)
process temperature (with FKM O-ring)
–40 to +150 °C (–40 to +302 °F)
polarization
reference
point
polarization
axis
display
For best results on a vessel with
obstructions, or a stillpipe with openings,
orient the front or back of the device
toward the obstructions (see
Mounting
on a Stillpipe or Bypass Pipe on page 18
for an illustration.)

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Installation
Mounting on a Stillpipe or Bypass Pipe
A stillpipe or bypass is used for products with a dK less than 3, or when vortex or
extremely turbulent conditions exist. It can also be used to provide optimum signal
conditions on foaming materials.
Stillpipe or Bypass Pipe requirements
An installation drawing number 23650689 is available on the product page of our website.
Go to: www.siemens.com/LR250 and click on Downloads.
• The pipe diameter must be matched with the horn size. Use the largest horn size
that will fit the stillpipe/bypass pipe (see Horn dimensions on page 11).
• Suitable pipe diameters: 40 mm (1.5") to 100 mm (4”).
Not recommended: (152.4 mm/6" or 203.2 mm/8")
• One continuous length of metallic pipe is preferred, without joints1.
Joints: must be machined to (± 0.25 mm [± 0.010”])
must have a welded connecting sleeve on the outside
• Bypass vent required at the upper end of the bypass2
• Vent hole/stillpipe slot diameter/height less than 5 mm (0.19") if possible, to
avoid affecting propagation.
Device orientation
1. Bad joints create reflections.
2. To equalize pressure and keep the liquid level in the bypass constant with the liquid
level in the vessel.
optimum
diameter
80 mm (3”)
align front or
back of
device with
vents
align front or back
of device with
stillpipe slots
vent hole diameter
preferably < 5 mm
(0.19")
Stillpipe Installation
preferably
< 5 mm (0.19")
slot
size
B
ypass Installation

7ML19985JE01 SITRANS LR250 (HART) – INSTRUCTION MANUAL Page 19
mmmmm
Installation
Installation Instructions
Threaded Version
1. Before inserting the device into its mounting connection, check to ensure the
threads are matching, to avoid damaging them.
2. Simply screw the device into the process connection, and hand tighten, or use a
wrench. A torque of 40 N m (30 ft.lbs) is recommended
Flanged Version
See Flanged Horn on page 11 and Flat Face Flange on page 12 for dimensions.
WARNING: For pressure applications, it will be necessary to use
PTFE tape or other appropriate thread sealing compound, and to
tighten the process connection beyond hand-tight.