Techno Scientific Co.

The most common technique used for measuring sheet resistance is the four-probe method. This technique involves using four equally-spaced, co-linear probes (known as a four-point probe) to make electrical contact with the material. Most four-point probes available commercially use sharp needles as probes. These can scratch or pierce delicate materials often used in thin film electronic devices. This can make it difficult to take accurate sheet resistance measurements, and result in the thin film becoming unusable.