The magnetostrictive measurement principle is based on the properties of certain materials that change under the influence of a magnetic field. One such material is the magnetostrictive wire, made from an alloy that reacts magnetically when exposed to an external magnetic field.

In level measurement using a float, the float is placed in the liquid whose level is to be measured. The float rises or falls with the liquid level and contains an integrated magnet. Surrounding the float is a tube that houses a coil. A short electrical pulse is sent through the coil to generate a magnetic field, which propagates along the tube until it reaches the magnet within the float.

When the magnetic field pulse reaches the float’s magnet, it causes magnetic alignment in the wire, resulting in mechanical elongation or contraction. This deformation generates an elastic wave that travels along the wire. The coil, also functioning as a receiver, detects the returning elastic wave and converts it into an electrical signal.

The time between sending the pulse and receiving the signal is measured. Since the speed of wave propagation in the wire is known, the liquid level can be calculated accurately. The magnetostrictive float thus enables precise liquid level measurement. The measured values can then be evaluated, displayed, or integrated into a control system to enable level indication or automatic control of filling processes.