Principle Of Operation; Safety Notes; Applications; Commissioning - Sick Lfp Inox Betriebsanleitung

EN
Operating instructions

1 Principle of operation

The LFP uses TDR technology (TDR: Time Domain Reflectometry). This is a process to determine
transit times of electromagnetic waves. A low-energy, electromagnetic pulse is generated in the
sensor's electronic components, coupled to the mono-probe and conducted along this probe. If this
pulse strikes the surface of the liquid to be measured, a portion of the pulse is reflected there and is
conducted back up along the probe path to the electronics, which then calculate the level based on
the time difference between the sent and the received pulse.
The sensor can output this level as a continuous measured value (analog output) as well deriving as
two freely positionable switching points from it (switching output). There is also an IO-Link communi-
cation available for switching output (Q1).

2 Safety notes

Read the instruction manual before commissioning.
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Connection, mounting, and setting only to be done by trained specialists.
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The LFP is not a safety module according to the EU Machinery Directive.
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Observe the national safety and work safety regulations.
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Repairs may only be carried out by the manufacturer. It is not permitted to make interventions and
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changes in the device.
Only carry out cabling work, opening and closing of electric connections when power is switched
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off.
The radiated power is far less than that from telecommunication equipment. According to current
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scientific knowledge, the operation of the device can be classified as posing no health risks.
Incorrect handling or improper use can lead to malfunctions in your application
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3 Applications

The innovative TDR technology makes reliable and nearly application-independent level monitoring
possible. The LFP is suitable for continuous level monitoring as well as for point level detection in
nearly all liquids.
Changes in the properties of the liquids to be measured will not influence it. Due to its hygienic
design, it is suitable for universal use in all liquids in the food industry. The LFP can only be used in
metallic containers or metallic bypass systems. The use at media temperatures of up to 150°C as
well as CIP and SIP compatibility mean the device is completely food safe. This has been certified by
an EHEDG certificate and FDA conformity. LFP is approved as overflow protection to WHG.

4 Commissioning

4.1 Mounting
The LFP is vertically mounted by its process connection from the top in the container or bypass. The
basic device has a G ¾ or ¾" NPT process connection. An appropriate connection adapter can be
used to make an aseptic process connection on the basic device with a G ¾ thread. A minimum
28 8014638/ZQ14/2017-08-25 © SICK AG • Level sensors • Germany • Subject to change without notice
1 Principle of operation
LFP