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How Does a Magnetostrictive Level Probe Work

September 10, 2021

Magnetostrictive level probes are continuous float level sensors that provide near real-time level measurement and feature high accuracy and high resolution.

The Working Principle of Magnetostrictive Level Probes

Magnetostrictive level probes is a level sensor designed and manufactured based on the principle of magnetostriction. Magnetostriction refers to the phenomenon that the change of the magnetization direction in the ferromagnetic substance will cause the change of the crystal lattice spacing of the medium, thereby resulting to the change of length and volume of the ferromagnetic substance.

                                                                       Magnetostrictive level probes are used for fuel level measurement


The structure of the magnetostrictive level probe is divided into three parts: float, transmitter and stainless steel measuring tube equipped with magnetowire. When the sensor is powered on, the pulse transmitter and receiver start to work. The transmitter periodically sends a low-current interrogation pulse signal to the lower end. The pulse and its magnetic field run down the magnetostrictive line. When the magnetic field of the pulse signal meets with that in the floating ball, a torsional stress pulse is generated and then is transmitted to both ends of the magnetostrictive line. The torsional stress pulse downwardly transmitted is absorbed by the damping, and that upwardly transmitted is received and detected by the receiver. According to the time difference from pulse sending to receiving of the returned pulse, the height of the liquid level can be calculated and converted into the output signal.

To get continuous fuel level measurement, we have other options except magnetostrictive level probes, such as radar level sensors, submersible pressure sensors and so on. Each has unique features that make them suitable or inappropriate for different applications. However, for gas station and underground fuel tank application, magnetostrictive level probes can be considered preferably.