请输入您要查询的字词:

 

单词 voltmeter
释义
voltmeter

Physics
  • An instrument used to measure voltage. Moving-coil instruments are widely used for this purpose; generally a galvanometer is used in series with a resistor of high values (sometimes called a multiplier). To measure an alternating potential difference a rectifier must be included in the circuit. A moving-iron instrument can be used for either d.c. or a.c. without a rectifier. Cathode-ray oscilloscopes are also used as voltmeters. The electronic digital voltmeter displays the value of the voltage in digits. The input is repeatedly sampled by the voltmeter and the instantaneous values are displayed.


Electronics and Electrical Engineering
  • A device that measures voltage. Voltmeters in common use include digital voltmeters, cathode-ray oscilloscopes, and d.c. instruments (such as permanent-magnet moving-coil instruments).

    In order to provide the minimum disturbance in the circuit containing the voltage to be measured, voltmeters are required to pass very little current and therefore require a very high input impedance. Digital voltmeters, cathode-ray oscilloscopes, and the now little used valve voltmeter comply with this requirement. A large series resistance however is required in the case of the moving-coil voltmeter and the electrostatic voltmeter in order to increase their input impedances. The electrostatic voltmeter is a voltmeter based upon the principle of operation of a quadrant electrometer or other type of electrometer.


随便看

 

科学参考收录了60776条科技类词条,基本涵盖了常见科技类参考文献及英语词汇的翻译,是科学学习和研究的有利工具。

 

Copyright © 2000-2023 Sciref.net All Rights Reserved
京ICP备2021023879号 更新时间:2024/6/30 23:39:59