Date: Mon Apr 30 18:03:08 2007

Author: Stan Dodds

Subject: Re: Student spectrometer recommendations?

We bought a batch of "Student Spectrometer"s from Surplus Shed, for $125.00 each plus shipping. A prism or grating
is additional. Since then, they added an "Intermediate Spectrometer",
which appears to be a knockoff of the Pasco unit, for $325.00.

The Student Spectrometers are the same basic design as the classic
Spencer units, but made in India and mechanically a bit crude. After
lubrication and some mechanical tweaking they have worked well for
several years, albeit with a limited number of students. Accuracy is
about 1nm when used with a grating on the hydrogen spectrum.

The gratings we obtained from Surplus Shed provide bright spectra, but
the actual line spacing is several percent off the marked value and
differs from unit to unit. I calibrated them against the hydrogen
spectrum, and we now get satisfactory results.


On Apr 30, 2007, at 2:16 PM, Andrew Dougherty wrote:

> Does anyone have a good recommendation for spectrometers suitable for
> introductory physics labs? We are currently using some home-built
> piano
> spectrometers, but are in need of additional units, and are hoping to
> avoid building them in-house.
> The spectrometers are currently used to measure the wavelengths of
> light from a hydrogen lamp. We don't need high precision or accuracy.
> That is, we're not looking at fine structure or trying to distinguish
> D2
> and H2. Accuracy to +- 10 nm would be fine for this group of students.
> I'm perhaps more interested in durability -- can we get consistently
> good performance year after year without laborious set-up each year.
> I'm aware of PASCO's "Student Spectrometer", but at $1159 per unit, it
> seems too expensive by about a factor of 3 for what we need.
> Thanks in advance,
> --
> Andy Dougherty
> Dept. of Physics
> Lafayette College, Easton PA 18042
> !DSPAM:4636420469171580722285!