Spectroscopy Activity
http://solar-center.stanford.edu/activities/cots.html
What is “Spectroscopy?”
Build a Spectroscope
1. Cut out pieces & fold
Cut along all of the red lines to
separate the pieces of the
spectroscope. You should now
have 8 pieces:
Spectroscope body
Gap Edge
Spacers(2)
Diffraction Grating
Eyepiece
Numbered Scale
Scale Cover
Write your name on the colored
side of the spectroscope body
where it say “This spectroscope
belongs to:”
2. Assemble Spectroscope Body
With the black side up,
use a straight edge to
crease the spectroscope
body along each of the
grey dashed lines. Then
fold the spectroscope
body closed (with black
side in). Put flap B over
flap A so they overlap and
tape edge as shown
3. Form wide scale side of Spectroscope
On the wide, open
side there are two
long flaps labeled
flap C and flap D.
Fold down flap D;
then fold down flap C
over it. Tape flap C
as shown. Then fold
down the small end
tab and tape corners
as shown.
4. Finish end of spectroscope
Fold down the end
tabs, then fold Flap C
down over the end
tabs as shown. Tape
the corners of the end
as shown.
5. Make entrance slit
Light must enter the spectroscope
through a gap formed between flap
C and the gap edge. The gap is
called the entrance slit. READ
CAREFULLY: it is important for the
gap to be straight and narrow, so
you will need to use the spacers.
Stack both spacers and sandwich
them between flap C and the gap
edge as shown. Hold the gap
edge tight against the spacers and
tape on the spectroscope. Then
remove the spacers from the gap.
You should be able to see through
the slit and it should be two
thicknesses of the poster paper.
Note: the slit will be a little offcenter but this is O.K.
6. Align & attach grating and eyepiece
At the narrow end of the
spectroscope, fold the end tabs
to form a square opening and
tape as shown. Next, cover the
square opening with the
diffraction grating. Before
taping, make sure your
diffraction grating is aligned
so that the word “Warning” is
facing out and cover the
“Warning” on the bottom end
tab. Tape the correctly aligned
grating securely in place. Tape
the eyepiece over the grating
with the “Warning” aligned.
7. Position scale
Place the numbered scale so it
covers the open side of the
spectroscope. When viewed
through the eyepiece, the 3000
end should be closest to the slit.
DO NOT TAPE UNTIL STEP 8.
Holding the scale in place while
looking through the eyepiece,
aim the spectroscope so you can
see a fluorescent light through
the slit. (It must be a fluorescent
light, an incandescent light bulb
will not work) You will se colored
lines on the scale – these are
spectral lines. If the spectral
lines appear above the slit
instead of over the scale, rotate
the diffraction grating ¼ turn.
8. Calibrate spectroscope
Slide scale back and
forth until dashed line at
5450Å is aligned with
green spectral line from
fluorescent lamp. The
tape scale in place.
Finally place scale cover
over the scale and tape it
only along the top edge.
That way you can lift the
scale cover if it is too
dark to read the scale.
Congratulations!
Your spectroscope is
fully operational.
Look at various
sources of light with
your spectroscope.
NEVER LOOK
DIRECTLY AT THE
SUN. (and if you do,
don’t do it with your
remaining eye)
Activities
Look at various sources of light
and draw the spectrum that
you see on the provided
worksheet.
Some suggestions are:
Fluorescent lamps
Light bulbs
TV’s or computers
A white object in sunlight
A colored object in sunlight
The Moon
Appendix A: Sample Spectra
Solar
 Hydrogen
 Helium
 Sodium
 Calcium
 Mercury
 Neon
 Argon
 Water

Appendix B: How does it work?
Appendix C: What is diffraction?