Requirements of a Shunt

1) The temperature coefficient of shunt and the meter should be low and should be as equal as possible.

2) The shunt resistance should be stable and constant with time.

3) The shunt resistance should not carry currents which will cause excessive temperature rise.

4) The type of material used to join the shunts should have low thermo dielectric voltage drop i.e. the soldering of joints should not cause a voltage drop.

5) Due to soldering, the values of resistance should not be change.

6) The resistance should have low thermal electromotive force with copper.

The manganin is usually used for the shunts of d.c. instruments while the constantan is useful for the shunts of a.c. instruments.