Moving iron type gauge - moving iron type gauge

...As an ammeter, it is desirable for the internal resistance to be small and as a voltmeter for the internal resistance to be large, and for both to have low power consumption.
[Moving iron type meter]
When a piece of iron is placed in a coil through which current flows, it becomes magnetized, and an attractive force proportional to the product of the magnetic field and the strength of the magnetization is generated. This force is used to magnify and indicate something, and there are various types, such as attraction, repulsion, and repulsion-attraction types.

*Some of the terminology used to refer to "moving iron gauges" is listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…電流計としては内部抵抗が小さく電圧計としては内部抵抗が大きく，いずれも消費電力の少ないことが望ましい。
［可動鉄片形計器］
　電流の流れるコイル中におかれた鉄片が磁化され，磁界と磁化の強さの積に比例した吸引力が発生する。これを利用，拡大指示させるもので，吸引，反発，反発吸引形などがある。…

※「可動鉄片形計器」について言及している用語解説の一部を掲載しています。

出典｜株式会社平凡社世界大百科事典 第２版について | 情報