Comparison between moving-iron (M.I) instruments and moving-coil( M.C)instruments

M.I Instruments M.C Instruments
It can be used for a.c as well as d.c voltage and current measurement. It is suitable only for the d.c voltage and current measurement.
Less sensitive as compared to MC instruments. It is much sensitive than M.I instruments.
Torque to weight ratio is less as compared to M.C type. Torque to weight ratio is high as compared to M.I type.
It is cheaper then MC and dynamometer. It is costlier then M.I and dynamometer type due to high cost of permanent magnets.
Air friction damping is used. Damping is perfect as eddy current damping is used.
Error are set due to hysteresis and stray fields. Error are set due to aging of control springs,permanent magnet.

Leave a Reply

Your email address will not be published. Required fields are marked *