Introductory material
Reading edition
Virtual value of an alternating current or pressure—the word effective erroneously used for virtual: steam engine analogy illustrating this error—classification of instruments: electromagnetic or moving wire, hot wire, induction, dynamometer—electromagnetic or moving iron instruments: types: plunger, inclined coil, magnetic vane; character of scale; objections and precautions—inclined coil instruments—magnetic vane instruments—hot wire instruments—induction instruments: types: shielded pole, rotary field; operation of both types—dynamometers: construction and operation; how arranged to measure watts—watthour meters: types: commutator, induction, Faraday disc; essential parts; object of the motor; object of generator; objection to commutator meter—principles of induction watthour meters: essential parts; strength of rotating field; moving element; retarding element; registering element; frame and bearings; friction compensator; power factor adjustment; frequency adjustment—Faraday disc, or mercury motor ampere hour meter: construction and operation—frequency indicators: types: synchronous motor, resonance, induction; synchronous motor as frequency indicator—resonance frequency indicators: adaptation—induction frequency meter: construction and operation—synchronism indicators: types: lamp or voltmeter, resonance or vibrating reed, rotating field—power factor indicators: wattmeter type; disc, or rotating field type—ground detectors.