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https://doi.org/10.3938/NPSM.65.328
Precision Electrical Measurement Experiment Using a Lock-in Amplifier that is Suitable for Science and Engineering Undergraduates
New Physics: Sae Mulli 2015; 65: 328~332
Published online April 30, 2015;  https://doi.org/10.3938/NPSM.65.328
© 2015 New Physics: Sae Mulli.

Soyeun PARK1, Yong J. LEE*2

1 College of Pharmacy, Keimyung University, Daegu 704-701, Korea
2 School of Mechanical Engineering, Kyungpook National University, Daegu 702-701, Korea
Correspondence to: yjlee76@knu.ac.kr
Received January 7, 2015; Revised February 5, 2015; Accepted February 25, 2015.
cc This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract
Despite the lock-in amplifier's being one of the most frequently used precision measurement instruments in science and engineering, most undergraduates students in physics know very little about the lock-in detection technique and never get a chance to experience or learn about the beauty of precision measurements. In this article, an introductory-level electrical experiment using a lock-in amplifier and designed for upper-level undergraduate science and engineering students is described. In the presented experiment, students measure the resistance of a small piece of copper wire, a piece that is often too small to be accurately measured with a multimeter, and calculate the resistivity of copper. As additional topics for discussion, the effects of $1/f$ noise on measurement uncertainties can be demonstrated with a lock-in amplifier, and AC impedance measurements for capacitors or inductors are equally possible when using the same setup.
PACS numbers: 01.30.L-, 84.37.+q, 07.05.Fb
Keywords: Lock-in amplifier, Resistivity, Undergraduate laboratory, 1/f noise


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