Re: Old double prism spectrometer
Proud Mary, Sat Dec 17 2016, 01:12AM

Marvellous! :)

Re: Old double prism spectrometer
Karmaslap, Sat Dec 17 2016, 08:54AM

Where did you find it?

Re: Old double prism spectrometer
Proud Mary, Sat Dec 17 2016, 10:38AM

I found this scheme for a simple spectroscope which looks a good start for experiments:

Re: Old double prism spectrometer
Physikfan, Sat Dec 17 2016, 04:35PM

Hi Karmaslap

I found this spectrometer at a flea market many years ago.

Re: Old double prism spectrometer
Physikfan, Sat Dec 17 2016, 04:49PM

Hi Proud Mary

in my post "neon spectra by transmission grating" of October 25, I have used almost exactly the same procedure:
a transmission grating in front of camera with a telefoto lens.
I have used the small capillary of the spectral tube instead of an additional slit.

If you compare the spectrum of the energy saving lamp of your source (Maurice Gavin) with the spectrum of my fluorescent lamp you see an excellent correspondence:

transmission grating spectrum, copyright Maurice Gavin

double prism spectrum of a compact fluorescent lamp, (mercury).

Due to the high dispersion (d n/d lambda) of the prism in the blue region the relative distance of the two blue lines of the prism spectrum is larger than the equivalent relative distance of these lines of the grating spectrum.

Re: Old double prism spectrometer
Proud Mary, Sat Dec 17 2016, 06:10PM

Good stuff!