Kelvin terminal
The Kelvin clamp is a four-wire clamp used in four-wire or four-wire measurements. It is a metrological arrangement that is independent of the conductor resistances of the test leads.
As can be seen from the name four-wire clamp, the Kelvin clamp works with two pairs of test leads of which one pair is used for the current supply, the other for the voltmeter.
The test leads for the voltmeter are also called sense leads and should be placed as close as possible to both measurement points when taking measurements. With this four-pole measurement, temperature influences and the contact resistances of the test leads are compensated and are not included in the measurement result.
In terms of concept, the Kelvin clamp is a bridge circuit in which no current flows in the bridge branch. The Kelvin contacts are gold-plated, which makes them corrosion-resistant and extremely low-resistance.