Peculiarities of calculating moving-coil instruments with a framed coil

Summary

• 1. The combination of modern materials for suspensions (for instance, platinum-silver alloys) with thermistor temperature compensation provides a very sensitive and high-class (0.1 to 0.5) moving-coil instrument design.

• 2. The calculation of combined multirange instruments (of the millivolt ampere-voltmeter type) can be reduced to the calculation of a simple-series millivoltmeter circuit with subsequent specification of the combined instrument circuit details.

• 3. Class 0.1 multirange combined instruments require a careful selection of measuring mechanisms by their temperature error and its spread.