Here are some more final hints for those who are still willing to participate actively:
(1) It makes sense to have an "easy going" specimen at hand which
can serve to check the basic function of our setup. For this sake we are recommending
carotene capsules from the grocery store. They can be opened and their content
squeezed onto an ordinary slide, and protected by a cover glass. The intensity values
reached with this specimen should be noted for later reference. Raman spectroscopy
does only work with perfect laser adjustment. So adjustment will take some time
and carotene will be helpful.
(2) The typical total measurement times with our setup are in the range of ca. 20 seconds to one minute.
They might be made up of e.g. of 10 runs, each lasting 6,000 milliseconds, summing up to one minute in total.
The background noise (the signal without the laser) must be subtracted manually when using the "Spectrum Studio" software.
Only then you will get clean spectra. More expensive software might perform the background subtraction automatically.
(3) Longer measurement times will cause additional noise problems: some pixels
of the spectrometer might behave erratically. You will have to experiment and find out
the optimum measurement time for your single runs. This is clearly a drawback of
our simple setup. Professional spectrometers might behave much better in this respect as
most of them are being cooled actively. As a consequence measurement times might last
20 minutes or longer with those instruments - which results in a much better signal to noise ratio.
(4) Please keep in mind that the laser light is not only dangerous for your eyes.
It might ruin the specimen as well. Minerals will cause no problems but
living micro organisms will be harmed or killed by strongly focused, high intensity laser radiation.