EN
FFU
Operating instructions
1 Principle of operation
8013863/10L9 /2018-08-01 © SICK AG • Fluid sensors • Germany • Subject to change without notice
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1 Principle of operation
Swimming against the stream requires greater physical strength than swimming with the stream. This
is the simple fact on which ultrasonic flow measurement according to the phase difference process is
based. Two sensors positioned opposite one another send and receive ultrasonic signals in alterna-
tion. When static media are used, both sensors receive the sent ultrasonic signal in phase, meaning
without phase difference. If flowing media are used, there is a phase shift. The phase shift is different
when measured in the direction of current than when measured against the direction of current. The
phase difference is directly proportional to the speed of the flow. The flow volume is determined from
the speed of the flow and the known diameter of the pipeline.
2 Safety notes
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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 FFU 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. Changing or altering the device is not permit-
ted.
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Wiring work and opening and closing of electrical connections are only to be carried out in a
de-energized state.
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Incorrect handling or improper use can lead to malfunctions in your application.
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FFU can be used by the Pressure Equipment Directive (PED) of group 2 only for „non-hazardous
liquids.“
3 Applications
The FFU flow meter is particularly suited for measuring highly dynamic processes in pipelines. The
device measures liquids. It can be used in the following applications, to name but a few:
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Chemical supply for controlling, logistics and monitoring
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Filling processes in the food industry
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Production machines for controlling and monitoring formulae
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Valve control for dosing liquid volumes
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DI water supply
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Dynamic processes
The following featured comprise its performance characteristics:
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no moving parts, and thus no wear
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high reproducibility
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ease of cleaning
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tamper-proof
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compact design
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integrated empty pipe detection
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chemical resistance
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integrated display with membrane keyboard