An Introduction to the Fourier Transform©
Scott Van Bramer Department of Chemistry Widener University Chester, PA 19013 United States mail to: svanbram@science.widener.edu
Abstract
The Fourier transform is used in many instrumental techniques, including infrared spectroscopy, NMR, and mass spectrometry. Although most instruments perform this mathematical technique transparently, an understanding of how it works is important. This understanding will help instrument users set appropriate parameters, appreciate the limitations of an instrument, and obtain better spectra. This document simultaneously introduces students to how the Fourier transform works and how various instrument parameters affect the results of the Fourier transform. Waveforms are produced and integrated using sine waves, cosine waves, and simple functions. The fast Fourier transform is used with simulated data to introduce students to the relationship between the signal waveform and the signal frequency of a spectrum. Students are then led to the concepts of dwell time and resolution through a series of interactive exercises. The document ends with an introduction to the Fourier transform of decaying signals. Students and teachers may use IntroFourierTransform.mcd as written, or teachers may remove some graphs to increase discovery learning and class discussion. IntroFourierTransform.mcd includes substantial student interaction by changing variables and written reflection exercises. The companion document, LectureIntroFT.mcd, designed for instructors to use interactively during lecture, is the abbreviated version of IntroFourierTransform.mcd. These Mathcad documents build on previously published work (1). (1) Van Bramer, S. Using Mathcad to Teach Instrumental Techniques. J. Chem. Educ. 1998, 75, 375-378.
Commentary
Editor's Commentary
Keywords
Audiences: Upper-Division Undergraduate Pedagogies: Computer-Based Learning Domains: Analytical Chemistry, Laboratory Instruction, Physical Chemistry Topics: Fourier Transform Techniques, IR Spectroscopy, Mass Spectrometry, Mathematics / Symbolic Mathematics, NMR Spectroscopy, Spectroscopy, Chemometrics
Documents
File Name Description Software Type Software Version IntroFourierTransform.mcd Mathcad Computational Document Mathcad LectureIntroFT.mcd Mathcad Computational Document Mathcad IntroFourierTransform.pdf Read-Only Document LectureIntroFT.pdf Read-Only Document JCE Subscribers only: name and password or institutional IP number access required.
Citations
Van Bramer, S. J. Chem. Educ. 1999 76, 286.
Comments to: Scott Van Bramer at svanbram@science.widener.edu
©Copyright 1999 Journal of Chemical Education