Float level gauges Type 746

Level gauges for top-mounting PN6 to PN100

Accessories for 746.1XXX.2

Transmitter feed circuit 4 - 20 mA, Ex i on request

Accessories generally

Principle of function

Magnetostrictive Level measurement
with ring magnet



with bar magnets

A ferromagnetic wire is penetrated simultaneously by a local longitudinal magnetic field from the float magnet and a circular magnetic field generated by a current pulse, which interferes at the position of the float magnet. This causes the Wiedemann-effect i.e. a striction onto the wire, which travels as a torsional wave along the wire with a specific sonic speed. The position of the magnet is determined precisely by measuring the runtime, which is directly proportional to the liquid level.

Principle of function Reed

The remote Control is actuated by the magnetic field of a magnet in a float. The circuit is equivalent to a 3-wire potentiometer-pickoff.
Corresponding to the float's position within the magnetic gauge tube the Reed-switches are actuated accordingly by the magnetic field. Those are tapering  the resistor-chain potentiometer without interruption.

The produced signal is discontinuous and proportional to the liquid level within the gauge tube.

Equivalent circuit

Float level gauges Type 748, dial type

Float level gauges for top-mounting up to 22 bar
alternatively equippably with:

applicable in zone 0, 1 and 2

Accessories generally

Principle of function 748