An ammeter shunt allows the measurement of current values too large to be directly measured by a particular ammeter. In this case, a separate shunt, a resistor of very low but accurately known resistance, is placed in parallel with a voltmeter, so that all of the current to be measured will flow through the shunt. The resistance is chosen so that the resultant voltage drop is measurable, but low enough not to disrupt the circuit. The voltage across the shunt is proportional to the current flowing through it, and so the measured voltage can be scaled to directly display the current value. Shunts are rated by maximum current, and voltage drop at that current. For example, a 500 A, 75 mV shunt would have a resistance of 150 microohm, a maximum allowable current of 500 amps and at that current the voltage drop would be 75 millivolts.

Precision Shunt Resistors are characterized by low temperature co-efficient, high stability of electrical resistance, low watt loss, and good heat dissipation. Furthermore, since mounting generally involves contact with copper, the copper welded to each side facilitates the mounting without the problems of thermo EF and galvanic action.

 
Electron Beam Welded SHUNT manufactured by Microhm using copper, MnCu or NiCr alloy strips forms an integral part of "Battery Management System" (BMS) or "Intelligent Battery Sensor" (IBS) for vehicles as well as "Electronic Energy Meter.” We have an integrated manufacturing capability from designing stage to bulk supplies.