Coercive Force Meter for magnetic parts in electromagnetic relay: Relay core, iron yoke, armature and other magnetic materials, such as electric meter compensation films, which are mainly made of pure iron materials, low carbon steel, iron-nickel alloy. Hc value is an important parameter of these materials. Hc value have relation with not only the materials, but also with the machining process by the mechanical stress and heat treatment process. In other words, Hc value of the same magnetic material would be wide different due to many factors in the processing. To the manufacturer of relays, the coercive force is directly related to the quality of the product. Similarly, in the production of mechanical energy meter, the coercive force of the compensation films are also directly related to the adjusting table results of energy meter, and affected production volume and quality accordingly. Therefore, the coercive force meter is the essential measurement instrument of the manufacturers who are producing the relays, energy meters, and other electrical pure iron, low carbon steel measuring the coercive force of open circuit magnetic materials.