2.7
The characteristics of the magnetic core materials discussed in this topic must be determined by certain specified procedures, which are usually in accordance with the standard test methods of the ASTM. The data obtained from such measurements can be used in a comparison of the electrical and magnetic properties and as a guide in the selection of the best material for a particular design. The test methods utilized can be classified in two general groups: those using direct current and those using alternating current as a source of power.