Spectrum tubes and CD spectroscopes

With no access to the computer laboratory for laboratory eleven, I opted to focus on spectra. This built off of the morning lecture on colors, color vision, color blindness , achromatopsia, color constancy, retinex and GIMP. In the laboratory session the students worked with CD-ROM based spectroscopes. In the afternoon class I built a third CD spectroscope. The afternoon section has more education majors, thus I felt they would benefit from seeing the construction process.

After viewing the continuous spectra of the sun, I dug out a box of old spectrum tubes and a spectrum tube power supply also from 1970. Exposed electrodes. 5000 volts. Probably time to buy one the newer units with shielded electrodes or the even newer models without through-the-glass electrodes.

The students above are viewing a tube that is optimistically labeled Neon. The labels have fallen off half the tubes, and while the tube boxes are also labeled, there is no guarantee that forty years on that the tubes are in the right box.

An unlabeled tube in a box marked Nitrogen produced a pinkish tinged orange light:

The tube produced the following image on a CD:

Enhanced by rebalancing with GIMP brings out some of the fainter spectral lines:

The afternoon class appeared to have a greater interest in the tubes and the lines produced by the tubes. The laboratory went well and might be developed into something more substantive if given labeled tubes and equipment that does not have a 30 second run time limit as was the case for the equipment in use today.

Jeanine uses a CD spectrograph to view the continuous spectra of the sun. The day was a cloudy day.