BALLUFF sensor range influencing factors introduction

What are the factors related to the BALLUFF sensor?
The BALLUFF sensor is the external pressure (or tension) that causes the geometry (length or width) of the strained material to change, which in turn causes the resistance of the material to change. Detecting this change in resistance can measure the magnitude of the external force. Piezoresistive pressure sensors are typically semiconductor pressure sensitive materials. After receiving an external force, the semiconductor piezoresistive sensor has almost no change in its geometry, but its lattice parameters change, affecting the forbidden band width. Even a very small change in the forbidden band width causes a large change in carrier density, which eventually causes the resistivity of the material to change. It can be seen that although the two materials exhibit a change in resistance to external force changes, the principle is different. In addition, the strain gauge material is much less sensitive to external forces than the semiconductor piezoresistive material. The sensitivity of the latter is about 100 times that of the former; the strain material properties are less affected by temperature, and the semiconductor piezoresistive material is sensitive to temperature.

The BALLUFF sensor consists mainly of a gradient magnetic field consisting of two semi-annular magnetic steels and a helium material semiconductor Hall plate (sensing element) device located at the center of the magnetic field. In addition, measurement circuits (bridges, differential amplifiers, etc.) and display sections are also included. Two DC magnetic circuit systems of the same structure form a gradient magnetic field along the x-axis. In order to obtain a better linear distribution of the magnetic field in the magnetic gap, a special form of pole piece is mounted on the magnetic pole face. The displacement sensor made with it is highly sensitive. The Hall plate is placed in two magnetic fields, and its initial position is carefully adjusted to make the Hall potential of the initial state zero. It has a small displacement and is suitable for measuring micro-displacement and mechanical vibration. When the Hall element is energized with a constant current, there is a Hall potential output in its direction perpendicular to the magnetic field and current. When the Hall element moves up and down in the gradient magnetic field, the Hall potential V of the output depends on its displacement x in the magnetic field. The static displacement of the Hall element can be known by measuring the magnitude of the Hall potential.