AEC SM720 User manual

1
www.alexsensors.com
SM720
Operation Instructions
Capacitive Level Transmitter
Reg. No. 059-A
WARRANTY
2
YEARS

Alex Electronics Co.
SM620 Capacitive Level Switches
SM720

Alex Electronics Co.
SM720 Capacitive Level Transmitter
Contents
1 About this document ..............................................................................................................................2
1.1 Function...............................................................................................................................................................................2
1.2 Target group.........................................................................................................................................................................2
1.3 Symbols used .......................................................................................................................................................................2
1 For your safety........................................................................................................................................3
1.1 Authorized personnel...........................................................................................................................................................3
1.2 Appropriate use ...................................................................................................................................................................3
1.3 Warning about incorrect use ...............................................................................................................................................3
1.4 General safety instructions..................................................................................................................................................3
1.5 Safety label on the instrument .............................................................................................................................................4
1.6 CE conformity......................................................................................................................................................................4
1.7 Environmental instructions..................................................................................................................................................4
2 About the Product ..................................................................................................................................5
2.1 Package Content..................................................................................................................................................................5
3 Installation ..............................................................................................................................................7
4 Connecting to Power Supply ...............................................................................................................10
4.1 Preparing the Connection .................................................................................................................................................10
1.1 Connection procedure .......................................................................................................................................................12
5 Calibration ............................................................................................................................................13
5.1 Calibration Procedures .....................................................................................................................................................13
6 Maintenance and fault rectification....................................................................................................14
6.1 Maintenance ......................................................................................................................................................................14
6.2 Rectify faults ......................................................................................................................................................................14
6.3 Exchanging the electronics module...................................................................................................................................15
7 Disposal .................................................................................................................................................16
7.1 Dismounting steps .............................................................................................................................................................16
7.2 Disposal.............................................................................................................................................................................16
8 Supplement ...........................................................................................................................................17
8.1 Technical Data...................................................................................................................................................................17
8.2 Dimensions ........................................................................................................................................................................18
8.3 Industrial property rights ..................................................................................................................................................19
8.4 Trademark..........................................................................................................................................................................19

Alex Electronics Co.
SM720 Capacitive Level Transmitter
1
Safety instructions for Ex areas
Take note of the Ex specific safety instructions for Ex
applications(Group2 ). These instructions are attached as
documents to each instrument with Ex approval and are part of
the operating instructions manual.

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SM720 Capacitive Level Transmitter 2
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
instructions for maintenance and fault rectification. 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 specialist
personnel. The contents of this manual should be made available
to these personnel and put into practice by them.
1.3 Symbols 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.
SIL applications:
This symbol indicates instructions for functional safety which must
be taken into account particularly for safety-relevant applications.
List:
The dot set in front indicates a list with no implied sequence.
Action:
This arrow indicates a single action.
Sequence of actions:
Numbers set in front indicate successive steps in a procedure.
i
SIL
•
1

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SM720 Capacitive Level Transmitter
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1 For your safety
1.1 Authorized personnel
All operations described in this operating instructions manual must
be carried out only by trained specialist personnel authorized by
the plant operator.
During work on and with the device the required personal protective
equipment must always be worn.
1.2 Appropriate use
UTS90 is a sensor for continuous level measurement.
You can find 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 specifications in the operating instructions
manual as well as possible supplementary instructions.
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 authorized by the manufacturer.
Arbitrary conversions or modifications are explicitly forbidden.
1.3 Warning about incorrect use
Inappropriate or incorrect use of the instrument can give rise to
application-specific hazards, e.g. vessel overfill or damage to
system components through incorrect mounting or adjustment.
1.4 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 flawless 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 regulations.
The safety instructions in this operating instructions manual,
the national 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 authorized by the manufacturer.
Arbitrary conversions or modifications are explicitly forbidden.
The safety approval markings and safety tips on the device must
also be observed.

Alex Electronics Co.
SM720 Capacitive Level Transmitter 4
1.5 Safety label on the instrument
The safety approval markings and safety tips on the device must
be observed.
1.6 Environmental instructions
Protection of the environment is one of our most important duties.
One of our goals is continuously improving company environmental
protection.
Please help us fulfill this obligation by the environmental
instructions in this manual:
• Chapter “Packaging, transport and storage”
• Chapter “Disposal”
1.7 Packaging, transport and storage
Your instrument is protected by packaging during transport.
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 specialized
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 ceiled 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
• Protected against solar radiation
• Avoiding mechanical shock and vibration
1.8 Accessories and replacement parts
The protective cover protects the sensor housing against soiling
and intense heat from solar radiation.
Electronics module “UTS80” is a replacement part for ultrasonic
sensors of UTS80. A different version is available for each model.
Packaging
Transport
Transport Inspection

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SM720 Capacitive Level Transmitter
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2 About the Product
2.1 Package Content
• SM720 device
• Warranty certificate
• Documentation of operating instructions
• Operating settings
• Serial number
Label Content
Typical Application
Advantages
Fig.1: SM720 Capacitive Level Transmitter
SM720 is suitable for use with liquids and solids.
It is a very accurate measuring device and the most common
measuring technique available.
The sensor works with conductive and non-conductive liquids
Example (water, oil, gasoline ) And fine and coarse grained solids
• Simple calibration steps
• Accurate measuring system
• Maintenance free device
• Capable of measuring solids and liquids
• Suitable for conductive and non-conductive liquids

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SM720 Capacitive Level Transmitter 6
Theory of Operation
Fig.2: Theory of operation
The principle of operation is based on the change of capacitance
between the probe and the silo or vessel wall.
The probe and the vessel wall form a capacitor CX
When the vessel is empty, the isolation medium between the two
electrodes of the capacitor (probe and vessel wall) is air which

When the material inside the vessel covers the probe, the
insulation medium between the two electrodes (probe and vessel

This change in the capacitance value is monitored by the electronic
card (inside the head house) which converts it to equivalent 4 - 20
mAoutput signal.

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SM720 Capacitive Level Transmitter
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3 Installation
When installing the SM720 sensor please check that the fitting
and the sensor material is suitable for the product and the vessel.
Install the sensor in a place that is easy to reach for connection
and calibration steps.
DON’T try to screw the sensor by holding the head doing this will
damage the sensor from inside and damage its electronics.
Instead screw the sensor by using a hexagonal key.
The sensor is installed vertically from above the vessel.
In case of wide diameter vessels choose a place that is 30-40 m
from the vessel wall to achieve the best accuracy.
General Instructions
Installation Position
Fig.3: Installing Position