Improvised multimeter for education

Authors

Benedicta M. Carambas Institute of Mathematical Sciences and Physics, University of the Philippines Los Baños

Abstract

An improvised multimeter is constructed in order to study the basic features and physical principles involved in the design of DC voltmeter, ammeter, or ohmmeter.
Using a portable galvanometer as basic instrument, a voltmeter, an ammeter and an ohmmeter of different ranges can be easily constructed. A voltmeter is constructed by inserting high-resistance multiplier in series with the galvanometer. On the other hand, connecting a low-resistance shunt in parallel with the galvanometer makes an ammeter.
An ohmmeter is constructed by placing a source and rheostat in series with the galvanometer so that when the circuit is closed without unknown resistance, Rx, the deflection of the pointer is maximum which means that current is maximum. If R_x is inserted there will be a corresponding decrease in the current proportional to the value of the resistance being inserted.
Placing it in parallel with a conventional voltmeter tests the constructed voltmeter. Inserting it in series with the regular ammeter likewise checks the constructed ammeter.

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Issue

2003: Proceedings of the 21st Samahang Pisika ng Pilipinas Physics Congress

Article ID

SPP-2003-WS-PE-09

Section

Panel Discussions, Workshops, and Tutorials

Published

2003-10-22

How to Cite

[1]

BM Carambas, Improvised multimeter for education, Proceedings of the Samahang Pisika ng Pilipinas 21, SPP-2003-WS-PE-09 (2003). URL: https://proceedings.spp-online.org/article/view/SPP-2003-WS-PE-09.