Influence Analysis of Sensor´s Nonlinearity on Output of Lock-in Amplifier

Author

Feng, Zhihua ; Liu, Rilong ; Yang, Dengfeng ; Kong, Fanrang

Author_Institution

Dept. of Precision Instrum. & Precision Machinery, Univ. of Sci. & Technol. of China, Anhui

Volume

3

fYear

2005

fDate

16-19 May 2005

Firstpage

1740

Lastpage

1743

Abstract

Generally the lock-in amplifier (LIA) can be used to detect very weak signal. This is based on the fact that any signal with a different frequency from that of the LIA´s reference signal will result in zero output. However, if the signal is measured by a sensor with some nonlinearity, the LIA indeed yields some mixed output that comes from the correlation between the measured signal and reference signal. This paper presents a theoretical analysis on the output of LIA. Furthermore, based on analysis results, a curve fitting method of measuring the sensor´s dynamic and tiny nonlinearity is provided. Experimental results verify that it is a useful measurement method when the accuracy is focused on

Keywords

amplifiers; curve fitting; electric sensing devices; curve fitting; lock-in amplifier; reference signal; sensor nonlinearity; Curve fitting; Dielectric liquids; Frequency measurement; Low pass filters; Noise measurement; Pollution measurement; RF signals; Radiofrequency amplifiers; Sensor phenomena and characterization; Signal to noise ratio; Lock-in Amplifier; nonlinearity; sensor;

fLanguage

English

Publisher

ieee

Conference_Titel

Instrumentation and Measurement Technology Conference, 2005. IMTC 2005. Proceedings of the IEEE

Conference_Location

Ottawa, Ont.

Print_ISBN

0-7803-8879-8

Type

conf

DOI

10.1109/IMTC.2005.1604469

Filename

1604469