Vierpunktmessverfahren

Vierpunktmessverfahren, also known as the four-point probe method, is a technique used to measure the electrical resistivity of a material. It is particularly useful for thin films and semiconductors where traditional two-point measurements can be inaccurate due to contact resistance. The method involves four equally spaced collinear probes that are brought into contact with the material's surface. A known current is passed through the two outer probes, and the resulting voltage drop is measured across the two inner probes. By applying Ohm's law and considering the geometry of the probe arrangement and the sample, the resistivity can be calculated. The accuracy of the measurement depends on the spacing of the probes, the cleanliness of the surface, and the assumption of an infinitely thick or semi-infinite sample, although correction factors exist for thin films and finite geometries. This non-destructive testing method is widely employed in material science and solid-state physics for characterizing the electrical properties of various conductive and semiconductive substances.