How is resistivity measured?

Resistivity is measured using several methods:

Four-Point Probe Method (most common):

• Four eually spaced probes contact the material
• Current passes through outer two probes
• Voltage is measured between inner two probes
• Eliminates contact resistance errors

Two-Point Method:

• Measures resistance directly using an ohmmeter
• Calculates resistivity using ρ = RA/L
• Simpler but less accurate for low-resistance materials

Van der Pauw Method:

• Used for thin films and irregularly shaped samples
• Reuires four contacts at the sample edges