Sciencemadness Discussion Board

$5 Spectrophotometer

Hexavalent - 17-9-2012 at 12:18

Incredibly, people at the University of Illinois have come up with this; a working spectrophotometer that uses a mobile phone camera and a few pounds/dollars worth of easily-obtained equipment.

www.asdlib.org/onlineArticles/elabware/Scheeline_Kelly_Spect...

SM2 - 17-9-2012 at 12:38

That's so awesome. Wonder if it does infrared, near IR."
Quote: Originally posted by Hexavalent  
Incredibly, people at the University of Illinois have come up with this; a working spectrophotometer that uses a mobile phone camera and a few pounds/dollars worth of easily-obtained equipment.

www.asdlib.org/onlineArticles/elabware/Scheeline_Kelly_Spect...

watson.fawkes - 20-9-2012 at 06:01

Quote: Originally posted by Fennel Ass Ih Tone  
Wonder if it does infrared, near IR.
A couple of quotations from the summary PDF should give some idea of the scope here:
Quote:
Sometime  during  2008,  it  occurred  to  the  corresponding  author  that  cell  phone  cameras  had 
become common among students.  "They're only 8 bit CMOS chips," was the initial thought.  "The 
signal‐to‐noise ratio will be terrible.  Dark current is likely to be a problem.  No one in their right 
mind would use such a poor detector for doing quality spectrophotometry."  In November, 2008, 
the author had a double‐take.  If all these measurement problems were so blatant, wouldn't that 
make the concepts behind the problems easier to sense and learn than if one used a high quality 
detector  and  system?
Quote:
To date, no student has reported an 
accurate, quantitative measurement.  Yet, in discussion, it appears that they understand gratings, 
stray light, and dispersion more clearly than do students who have only heard of or seen pictures of 
the instrument components.
This is an educational tool. If you want to build your own spectroscope, learn the basics with this project. Then build a real one.

Hexavalent - 20-9-2012 at 06:56

I am aware that it is never going to be perfect, but for this cost who can complain? It will, yes, be of great educational benefit yet I'm sure that, if built and used well, it could be a useful tool at times, even if just for preliminary analysis.