Cell Phone Spectrophotometer

A Guided Inquiry Approach to Teaching How to Think About Analytical Instrumentation

Alexander Scheeline and Kathleen Kelley

Department of Chemistry
University of Illinois at Urbana-Champaign
600 S. Mathews Ave.
Urbana, IL 61801 USA

Creative Commons License
Cell Phone Spectrophotometer by Alexander Scheeline is licensed under a Creative Commons Attribution 3.0 United States License.
Based on a work at scheeline.scs.illinois.edu.
Permissions beyond the scope of this license may be available at http://scheeline.scs.illinois.edu.

Please read the paper under the Exposition link, then harvest other links as appropriate.

Now available in Romanian and Indonesian! This website has been linked to Science Buddies for students to use as a science project.

Software now works with international character sets. Annamaria Lisotti, a high school teacher in Italy, patiently worked with the authors to identify previous limitations, debug, and remove them.

Exposition PDF of baseplate Executable Software
Windows Android (LearnLight) iPad
Supplementary Details Baseplate AutoCAD file Software Source Files
High School Teacher Module Student Module Related Work by Others

World's Cheapest Spectrophotometer Grating with spring clips

Clear tape or spring clips -- either can support the diffraction grating. Russ Davidson of San Dieguito Academy High School, Encinitas, CA invented the spring clip approach.

Notice: Executable and Source files are updated 3/7/2012.
Link here is to original executable and the June, 2011 update.

Earlier version had errors in computing transmittance and absorbance if the number of pixels in the sample spectrum differed from the number in the reference spectrum.
Output to .CSV files had errors in %T and A, but had correct data for intensity and thus could be correctly employed for computing transmittance and absorbance.
The most recent version makes a .TXT file instead of a .CSV file and is Tab-delimited for better international compatibility.