As I understand your question, you want to know different ways of current measurement. I hope following description will be useful. One of the simplest measurement methods is the direct comparison of measured value with the standard one. An example of the direct measurement method is presented in Figure below. In this method the idea of weighting it is applied (this method is sometimes called the current weight). One coil of the electromagnet is supplied by the measured current Ix , which causes that the ferromagnetic element on one arm of the balance is attracted. (It is possible to use also other electric mechanism, for example attracting of the magnet or attracting other coil