Clamp multimeter:
The measurement current part of the clamp multimeter is composed of a current transformer and the current measurement part of the multimeter. The core of the transformer has a movable part and is connected to the handle, when used, press the handle to make the movable core open. Will be measured current wire into the jaws, after releasing the handle to make the core closed. At this time through the current wire is equivalent to the primary winding of the transformer, the secondary winding will appear induced current, the size of the wire by the working current and the number of winding turns than to determine. Ammeter is connected to the ends of the secondary winding, and thus the current it indicates is the current in the secondary winding, this current is proportional to the current in the work. Therefore, the imputed scale as a reflection of the primary side of the flow of electricity, when there is a current through the wire, and the secondary winding connected to the ammeter pointer will be proportional to the occurrence of deflection, thus indicating the value of the measured current.