General Functional Description - HYDAC ELECTRONIC HNT 1128-F11- -000 Série Notice D'utilisation

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3 General functional description

The measuring method is based on a runtime measurement (in the ultrasonic range).
The ultrasound propagation runtime is proportional to the distance and is processed in
an evaluation unit. A ferro-magnetic conductor is tensioned and supplied with a current
pulse (magnetostrictive measuring element – wave guide) inside a tubular cable
protection. From the current pulse, a radial magnetic field arises around the conductor.
The position sensor (permanent magnet) is a non-contact and wear-free magnetic
measurement system (float), which produces an axial magnetic field with regard to the
wire. When the two magnetic fields meet at the measuring point moving radially from the
wire and axially from the float magnet, then a torsion pulse will be generated.
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The resulting torsion pulse spreads out from the sensor with constant ultrasonic speed,
moving along the waveguide in both directions. Over a sensing element in the sensor
head the ultrasonic sound signal is recorded and converted into an electrical way-
proportional output signal.
The measured delay between sending out the current pulse until the torsion pulse
arrives is converted into a proportional output signal and makes this available as a digital
or analogue signal.
Status: 2017/06/02
HYDAC ELECTRONIC GMBH
HNT 112x-F11-xxxx-000
Mat. No.: 669923