Alignment of Instrument 2:
1. Set up Main laser diode so primary lens is aligned such that laser comes out level and
straight.
2. Remove 2nd lens, sample compartment and detectors for main laser (ML) and alignment
laser (AL).
3. Put in alignment jigs for main laser (MLJ) and alignment laser (AMJ).
4. Move main laser until it hits front slit and back line of MLJ.
5. Check if AL is close to ALJ slit.
a. If it is close move AL lens to make beam hit ALJ slit.
b. If AL beam is far off remove lens from AL
i. loosen screw that locks AL down (on base behind laser).
ii. move AL until bean goes through ALJ slit.
iii. tighten AL down
iv. replace lens on AL
v. move lens on AL so that beam goes through ALJ slit.
6. Replace sample compartment with Toluene inside and heat conducting grease on bottom
7. Move sample compartment so that beam hits ALJ and MLJ correctly
8. Mount 2nd lens for ML.
9. Move 2nd lens until beam hits sample cell in
Main laser
center and MLJ on slit.
Sample
10. Put AL detector and ML detector back on
ML2nd lens
compartment
table
Alignment
laser
11. Put 4001 in coarse.
12. Move ML and AL detectors so that diodes
Alignment
on PC board inside instrument are red and
detector
AL lens
maximized.
ML
detector
13. Make detectors snug but not tight
14. Put 4001 in fine
15. Move ML and AL detectors so that diodes on PC board are now in center and green.
16. Lock down detectors.
DLS Detector alignment
1. Put sample in cuvette and insert into instrument (want a strong scatterer 5 mg/ml bsa)
2. Turn off DLS detector.
3. Turn on AL.
4. Adjust cuvette position until diodes show green and are in the middle (they tend to keep
moving).
5. Put eye piece in back DLS aperture position (away from sample).
6. Remove front aperture.
7. Check that no laser light is coming out of eye piece.
Cross hairs
8. Look at beam through eye piece.
9. Should see figure on right.
Laser beam
10. Move back lens (lens inside the detector housing) to
focus laser beam.
Laser scatter
walls of cell
11. Move external lens (lens on front of detector housing). to align horizontal crosshair with
beam and vertical crosshair with in center of beam.
12. Remove eyepiece and replace both apertures.
13. Turn on detector check that counts are < 2.5 x 106 counts.
a. If counts too high: lower laser power and/or add a smaller aperture to front
aperture.
b. If counts < 5 x 105: raise laser power and/or open front aperture.
14. Turn on DSL data taking and set so it updates screen every time it takes data.
15. Adjust front lens so that autocorrelation decay is a max
16. Done.