Introduction to Spectra of Light

Using a spectrometer- calibration

Never look directly at the sun ether with your eyes or with the spectrometer that you will build. 
After building your spectrometer find a light source and become familiar with what your home built spectrometer can do.  As we state above, you should never look directly at the sun.  The sun’s spectrum contains ultraviolet (UV) radiation which can cause permanent damage  to your eyes.

After you get familiar with the spectrometer, you are now ready for the next step which is assigning the proper wavelength to the spectral lines you are seeing. You can do that by using the spectralworkbench.org software. Note: if this is your first time to use the software, we recommend that you use the webcam on your laptop for first time calibration. To be able to work with spectralworkbench.org software you need to do the following:
1) Create a profile on spectralworkbench.org.
2)  After you log in you can use the capture spectra at the top right corner.
3)  Use a fluorescent light to capture the spectrum using your spectrometer and a camera. This picture will be used to calibrate the software, so it can identify the wavelengths. If you  run into the saturation problem,  you can compensate by carefully moving the light to where saturation is minimized or by using a semi clear tape at the slit side which works as light diffuser. (See our instructions.) We also recommended that the slit in the spectrometer and the light source be at the same height.
4)  Use live capture spectra under capture spectra bottom at the top left.  A message appears asking you to allow spectralworkbench.org to use your webcam, click OK.
5)  Now adjust the line on your image from the webcam to the brightest and clearest position of the image. Then click start capturing spectra.
6)  After you capture the image and this is your first calibration or you want to try a new calibration. Then click calibration and follow the instruction they give you.  The fluorescent light contains mercury, and the software compares the mercury spectrum with the lines from your spectroscope. Below is an example of a fluorescent light spectrum calibration.
Example of the calibration screen using spectralworkbench.org software. indicated the 436nm and 546nm spectral lines for Mercury in the fluorescent light.

After you are satisfied with your calibration, you can try the following:
 
* If you have a laser pointer(don't look with your eyes through the spectrometer to the laser it can damage your eye), what do you think the spectrum look like? Write your prediction? Now use your spectrometer and the software to test your prediction.


* We provide you with different color LEDs, What do you think each LED color will give you?



* Be creative, try to look at the spectrum of many things around you, if you have a  LED flash light, candle, you can pass light through food coloring, honey etc.
 




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