Electronic spirit level

Fluid-based biaxial inclinometer for small angle ranges

Inclinometers are sensors that determine the position angle of an object relative to the gravitational field of the earth. We develop fluid-based biaxial inclinometers. These are suitable for applications where extremely high resolutions and accuracies in the measuring range of a few angle degrees with long-term stability are required. Typical areas of use are measuring technology, building and agricultural machines or automation technology, The liquid level, which is always aligned horizontally in the cavity of the sensor cell, results in a capacity change that is dependent on the tile angle when the electrodes are rotated. 

Examples of application possibilities include online monitoring of the leveling of machines, geological surveying, building monitoring, or monitoring of off-shore wind farms.

The familiar functional principle of the spirit level is combined with a capacitive measurement for determination of the position of the air bubble. The sensor consists of a printed circuit board that carries the electrodes, as well as the electronics for measuring capacitance. A dome is soldered onto the printed circuit board. The hollow space provided by the dome is partially filled with a dielectric fluid so that an air bubble forms below the spherical inner surface of the dome. In this process capacitance is built up between the electrodes on the PCB and the sensor dome that is partially filled with fluid. If the sensor is tilted, the bubble wanders inside the dome. The electrodes on the PCB are arranged in such a manner that the position of the bubble can be capacitively. Thus when evaluating the capacitance differentials, the angle of inclination around two mutually perpendicular spatial axes can be determined.


Dipl.-Ing. Adrian Schwenck
Phone: +49 711 685-84790