Linear measurement in piston-cylinder arrangements

A device for sensing a change in the extension of a piston-cylinder arrangement, the device comprising:

• the piston-cylinder arrangement, which comprises a cylinder and a piston that is movable within the cylinder,
• an electrical circuit unit, which is configured to apply a DC voltage (Vcc) to the piston-cylinder arrangement, and
• a capacitance determination unit, which is configured to determine a capacitance (C) of the piston-cylinder arrangement,
• wherein the electrical circuit unit is configured to generate a pulsed DC voltage (Vcc) on the basis of the sensed capacitance (C) of the piston-cylinder arrangement,
• the device further comprising:
• a measuring unit, which is configured to measure a frequency (F0, F1) of the pulsed direct current (Vcc) generated, and
• an evaluation unit, which is configured to determine a frequency difference (DF) between the frequency (F0) of the pulsed direct current (Vcc) before displacement of the piston within the cylinder and the frequency (F1) of the pulsed direct current (Vcc) after displacement of the piston within the cylinder, and which is further configured to determine a displacement distance of the piston within the cylinder on the basis of the frequency difference (DF).