Tvåtrådsmetoden

Tvåtrådsmetoden, also known as the two-wire method, is a technique used in electrical measurements, particularly for determining resistance. It involves using two wires to connect a measuring instrument, such as an ohmmeter, to the component being tested. One wire carries the current from the source to the component, and the other wire carries the current back to the source.

The primary advantage of the two-wire method is its simplicity. It requires minimal wiring and is straightforward to implement. However, it has a significant limitation: it does not account for the resistance of the connecting wires themselves. This means that the measured resistance will include both the resistance of the component and the resistance of the wires. For components with very low resistance, the resistance of the wires can be a substantial portion of the total measured value, leading to inaccurate readings.

This method is generally suitable for measuring relatively high resistances where the resistance of the connecting wires is negligible in comparison. For accurate measurements of low resistances, a four-wire method (Kelvin sensing) is typically preferred, as it uses separate pairs of wires for current carrying and voltage sensing, effectively eliminating the influence of lead resistance. Despite its limitations, the two-wire method remains useful in many practical applications where high precision is not critical or when dealing with components that have significantly higher resistance than the connecting wires.