AQ-00275-000, Rev. 3
10
tance positions is for measurements using a center mount sample holder. Make sure
that mirror M3 is in the desired location (reflectance, center mount, or transmittance).
See the
Installation
section of this manual for instructions on how to move M3, if
necessary.
6. Place a piece of translucent paper or a white card in the beam path in front of M2.
Turn the adjustment screws of mirror M1 until the beam is centered on M2.
7. Place the translucent paper or white card in the beam path in front of M3. Turn the
adjustment screws of mirror M2 until the beam is centered on M3.
8. Make adjustments to mirror M3 using the translucent paper or white card and one of
the following steps.
a. For reflectance measurements, turn the adjustment screws of mirror M3 until the beam
is centered on the opening at the 8
°
wedge at the sample reflectance port. The beam
should not overfill the port.
b. For
transmittance measurements,
turn the adjustment screws of mirror M3 until the
beam is centered on the transmittance sample port. In this configuration, the sample
beam will overfill the reflectance port, but it should be tightly focused at the transmit-
tance port. The sample beam is now aligned.
c. For center mount use, load the translucent paper or card into the center mount sample
holder. Turn the adjustment screws of mirror M3 until the beam is centered on the
sample area but does not clip the edges of the transmittance port.
8. Place the paper or white card in the beam path in front of M5. Turn the adjustment
screws of mirror M4 until the reference beam is centered on M5.
9. Turn the adjustment screws of mirror M5 until the beam is centered on the reference
port. If using a center mount sample holder, the reference beam should pass directly
in front of the the center mount device.
M1
M2
M3
M4
M5
Sample Reflectance
Port
Reference Port
Sample Transmittance Port
Port Covers
Reference
Beam
Sample
Beam
Figure 5. Top view of the DRA-CA-3300 accessory.