Kelvinjohtimia

Kelvinjohtimia, also known as Kelvin connections or Kelvin pairs, are a type of electrical connection used to minimize the effects of resistance in measurement circuits. They are named after Lord Kelvin, who first proposed their use. The primary purpose of Kelvin connections is to reduce the voltage drop across the current-carrying leads, which can introduce errors into measurements.

A standard Kelvin connection consists of two pairs of wires. One pair carries the current to the device being measured, while the other pair measures the voltage across the device. The current-carrying wires are connected to the device at one end, and the voltage-measuring wires are connected at the other end. This arrangement ensures that the voltage drop across the current-carrying wires does not affect the voltage measurement.

Kelvin connections are commonly used in applications where high accuracy is required, such as in precision resistance measurements, strain gauges, and thermocouples. They are also used in four-wire resistance measurements to minimize the effects of lead resistance.

The effectiveness of Kelvin connections depends on the quality of the connections and the symmetry of the circuit. Proper grounding and shielding are also important to minimize noise and interference. In practice, Kelvin connections can significantly improve the accuracy of measurements by reducing the effects of lead resistance and voltage drops.