Kontaktivastusmittaus

Kontaktivastusmittaus, also known as contact resistance measurement, is a method used to determine the electrical resistance at the interface between two conductive materials. This measurement is crucial in various applications where electrical connections are made, as high contact resistance can lead to power loss, overheating, and unreliable performance. The principle behind it is Ohm's Law, where resistance is calculated by measuring the voltage drop across the contact point when a known current is applied.

The measurement is typically performed using specialized equipment such as micro-ohmmeters or Kelvin bridges. The Kelvin bridge method, also known as four-terminal sensing, is particularly effective for minimizing the influence of the test leads and the resistance of the measurement instrument itself. This is achieved by using separate pairs of leads for current injection and voltage measurement. One pair supplies the current to the contact, while the other pair measures the voltage drop directly across the contact area.

Applications for kontaktivastusmittaus are widespread, including quality control in electrical component manufacturing, maintenance of power distribution systems, and testing of connectors in electronic devices. In power systems, excessive contact resistance in switchgear, busbars, or terminals can indicate poor connections, corrosion, or wear, necessitating inspection and maintenance to prevent failures. In electronics, it is vital for ensuring signal integrity and minimizing power dissipation in connectors and circuit board traces. The accuracy of the measurement depends on factors such as the applied current, the surface condition of the materials, and the pressure between them.