Hardware project: Build an inexpensive spectrophotometer - Revision history

imported>Projects221: /* Appendix I - Data */

2014-03-21T04:57:43Z

Appendix I - Data

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	= Appendix I - Data =		= Appendix I - Data =

	[[Media:~~FilterScript~~.m\|~~Filter Script]]~~		[[Media:ProjectData.zip\|Project Data]]

	~~[[File:PRS650results.zip]]~~

	~~[[File:InexpensiveResults.zip~~]]

	= Appendix II - Work partition (if a group project) =		= Appendix II - Work partition (if a group project) =

imported>Projects221: /* Appendix I - Data */

2014-03-21T04:55:57Z

Appendix I - Data

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	= Appendix I - Data =		= Appendix I - Data =

	[[~~File~~:FilterScript.m]]		[[Media:FilterScript.m\|Filter Script]]

	[[File:PRS650results.zip]]		[[File:PRS650results.zip]]

imported>Projects221: /* Appendix I - Data */

2014-03-21T04:52:17Z

Appendix I - Data

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	= Appendix I - Data =		= Appendix I - Data =

	~~[[File:Example.jpg]]~~

	[[File:FilterScript.m]]		[[File:FilterScript.m]]

imported>Projects221: /* Appendix I - Data */

2014-03-21T04:51:59Z

Appendix I - Data

← Older revision		Revision as of 04:51, 21 March 2014
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	= Appendix I - Data =		= Appendix I - Data =

	[[File: ~~filterScript~~.m]]		[[File:Example.jpg]]

	[[File: ~~PRS650results~~.~~zip~~]]		[[File:FilterScript.m]]

	[[File: InexpensiveResults.zip]]		[[File:PRS650results.zip]]

			[[File:InexpensiveResults.zip]]

	= Appendix II - Work partition (if a group project) =		= Appendix II - Work partition (if a group project) =

imported>Projects221: /* Appendix I - Data */

2014-03-21T04:50:29Z

Appendix I - Data

← Older revision		Revision as of 04:50, 21 March 2014
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	= Appendix I - Data =		= Appendix I - Data =

	[[File: ~~fiberimages~~.~~zip~~]]		[[File: filterScript.m]]

	[[File: ~~spectra~~.zip]]		[[File: PRS650results.zip]]

	[[File: ~~Illuminator CAD~~.zip]]		[[File: InexpensiveResults.zip]]

	= Appendix II - Work partition (if a group project) =		= Appendix II - Work partition (if a group project) =

imported>Projects221: /* Results */

2014-03-21T04:47:47Z

Results

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	As seen in the above plot, although the reflected light allowed the PRS650 to measure the incandescent light source, it still picks up a significant amount of infrared. This has an overall effect of washing out the rest of the visible spectrum. Therefore, we digitally filtered out the IR spectrum data and limited measurements to 650nm wavelength. This data was then compared to the spectrum obtained from the inexpensive device for the same wavelength range.		As seen in the above plot, although the reflected light allowed the PRS650 to measure the incandescent light source, it still picks up a significant amount of infrared. This has an overall effect of washing out the rest of the visible spectrum. Therefore, we digitally filtered out the IR spectrum data and limited measurements to 650nm wavelength. This data was then compared to the spectrum obtained from the inexpensive device for the same wavelength range.
	The plot below overlays the spectrum from the inexpensive and PRS650 using an incandescent light source with a blue color filter. The intensities follow a similar trend across the range of wavelengths. There especially seems to ~~bea~~ good fit in the blue light range (420 to 480nm).		The plot below overlays the spectrum from the inexpensive and PRS650 using an incandescent light source with a blue color filter. The intensities follow a similar trend across the range of wavelengths. There especially seems to be a good fit in the blue light range (420 to 480nm).

	[[File:compared.jpg\|thumb\|500px\|center\|Compared spectra of blue filtered light from incandescent source]]		[[File:compared.jpg\|thumb\|500px\|center\|Compared spectra of blue filtered light from incandescent source]]

imported>Projects221: /* Apparatus Design */

2014-03-21T04:38:57Z

Apparatus Design

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	2) ''' Cereal Box Design '''<br/>		2) ''' Cereal Box Design '''<br/>
	This design made use of reflective diffraction pattern. Light is incident on the DVD diffraction pattern and is reflected off the silvered side of the DVD. The DVD is angled at 60 <math>\deg</math> to the plane of the incoming light. The light hits the diffraction pattern and is reflected off the silvered side of the DVD. The reflected image is captured and is uploaded on ~~spectralworkbench~~ to examine the spectrum.		This design made use of reflective diffraction pattern. Light is incident on the DVD diffraction pattern and is reflected off the silvered side of the DVD. The DVD is angled at 60 <math>\deg</math> to the plane of the incoming light. The light hits the diffraction pattern and is reflected off the silvered side of the DVD. The reflected image is captured and is uploaded on Spectral Workbench to examine the spectrum.
	[[File:cereal_box.jpg\|thumb\|400px\|center]]		[[File:cereal_box.jpg\|thumb\|400px\|center]]

imported>Projects221: /* Background */

2014-03-21T04:34:36Z

Background

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	Gautam Narasimhan and Ashwin Shankar		Gautam Narasimhan and Ashwin Shankar
	= Background =		= Background =
	The goal of this project was to build an inexpensive photo-spectrometer and compare its performance to the expensive PRS650 in the VISTA lab. The parts chosen for the design are simple off-the-shelf components that are available at any office supply store. While expensive lab-grade spectrometers are used for research purposes including astronomy, gas analysis and crystallography, the inexpensive spectrometer will be used by amateur users for purposes like brewing, checking the fat content in milk and examining soil samples. The inexpensive photospectrometer described below costs less than $10. Components were obtained and an apparatus was designed to focus light on the diffraction grating. The picture of the diffracted pattern was taken with the help of a phone camera and the Spectral workbench software on ~~the~~ publiclab.org ~~website~~ was used to analyze the data.		The goal of this project was to build an inexpensive photo-spectrometer and compare its performance to the expensive PRS650 in the VISTA lab. The parts chosen for the design are simple off-the-shelf components that are available at any office supply store. While expensive lab-grade spectrometers are used for research purposes including astronomy, gas analysis and crystallography, the inexpensive spectrometer will be used by amateur users for purposes like brewing, checking the fat content in milk and examining soil samples. The inexpensive photospectrometer described below costs less than $10. Components were obtained and an apparatus was designed to focus light on the diffraction grating. The picture of the diffracted pattern was taken with the help of a phone camera and the Spectral workbench software on [http://www.publiclab.org Public Lab] was used to analyze the data.

	= Optics =		= Optics =

imported>Projects221: /* Apparatus Design */

2014-03-21T04:31:28Z

Apparatus Design

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	2 razor blades<br/>		2 razor blades<br/>
	1 DVD<br/>		1 DVD<br/>
	~~Box of cereal <br/>~~
	30-60-90 Set square		30-60-90 Set square

imported>Projects221: /* Conclusions */

2014-03-21T04:30:12Z

Conclusions

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	[[File:comparison_table.jpg\|thumb\|500px\|center\|Table comparing the lab spectrometer with the two inexpensive designs ]]		[[File:comparison_table.jpg\|thumb\|500px\|center\|Table comparing the lab spectrometer with the two inexpensive designs ]]
	In the future, a light source with variable intensity could be used in order to
			In the future, a light source with variable intensity could be used in order to test sensitive (PRS650) and less sensitive spectrometer designs without changing the test setup. In addition, the designed spectrometer could also be tested with actual application of spectroscopy such as identify liquids through spectral absorption.

	= References - Resources and related work =		= References - Resources and related work =