Thermo Scientific 20 GENESYS, Service Manual

Page: 42 / 205

Optical Alignment
7 - 2
Figure 7.1
Fabricated Alignment Tool
CAUTION
MOST ASSEMBLIES ARE MOUNTED TO THE PLASTIC HOUSING
WITH THREAD-FORMING SCREWS. ALWAYS BE CAREFUL TO
NOT OVER TIGHTEN THESE SCREWS OR THEY WILL STRIP OUT
THE HOLE. THIS WILL IMPAIR THE ABILITY OF THE SCREW TO
PROPERLY SECURE THE ASSEMBLY.
7.1
Filter And Lens
Assembly
Alignment
Most of the optical components of the GENESYS 20 Spectrophotometer are
fixed at the factory and are not field adjustable. The filter and lens assembly is
the one component which may require field alignment. This alignment should be
checked each time the unit is serviced. It must be aligned if found to be
improper. It must also be aligned if the filter wheel assembly is replaced. (Refer
to "Section 9 - Disassembly and Replacement" for instructions on replacing the
filter and lens assembly.)
7.1.1
Alignment Tool Alignment of the filter and lens
assembly requires an alignment tool.
Spectronic instruments has a
commercially available alignment
tool (part number H-152378).
However, an alignment tool can also
be easily fabricated for use in the
alignment procedure. To fabricate
the alignment tool:
1. Cut out a piece of paper 10
mm wide by approximately
20mm long.
2. Draw a thin, dark line
exactly down the center of
the paper.
3. Place the paper into a sample cuvette so it slants diagonally from front
to back across the cuvette.
7.1.2
Alignment Check 1. Remove the power cord from the instrument.
2. Remove the cover assembly (refer to "Section 9 - Disassembly and
Replacement").
3. Disconnect the filter wheel motor cable from the main circuit board.