ASSESSMENT OF SYNCHRONIC DETECTION AT LOW FREQUENCIES THROUGH DSP-BASED BOARD AND PC SOUND CARD

Mateusz Kotarski, Janusz Smulko

Abstract

The lock-in amplifier, working at acoustic frequency range, can be cheaply realized by applying a sound card or a board kit with a digital signal processor, together with a low noise amplifier. Such realization can automatically retune frequency and can perform fast measurements at various frequencies to establish frequency characteristic of the investigated, and often time-varying, object. Quality of these two economical solutions is presented in detail and the possible improvements to limit measurement errors are discussed as well.

Keywords

lock-in amplifier, noise, accuracy

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IMEKO-WC-2009-TC4-291.pdf

DOI

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IMEKO TC

TC4 - Measurement of Electrical Quantities

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