DH Instruments ADCS-601, Operation And Maintenance Manual

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ADCS-601™ OPERATION AND MAINTENANCE MANUAL
© 2005 DH Instruments, Inc. Page 46
they execute. See Section 6.5 for additional information on installing and
removing AMH-38 from the PG7601 Platform.
Visually inspect the condition of the AMH-38 mass handler by carefully
tipping it to look inside. The main mass selection columns should have all
their flat surfaces (no ledges) oriented towards the center and all binary
mass selection pins should be retracted. If these conditions are present the
AMH-38 is ready to install on the PG7601 Platform.
Install the AMH-38 mass handler onto the PG7601 Platform (see Section
6.5.1, Figure 50). Verify that the O-ring is installed on the bottom
circumference of the AMH-38 vacuum chamber. Using the handles on the
side of the AMH-38 vacuum chamber, lift the AMH-38 above the PG7601
platform and masses. Center it over the mass load and gently lower it down
until the bottom circumference of the AMH-38 vacuum chamber reaches the
PG7601 vacuum plate. Check that the vacuum chamber is well aligned on
the vacuum plate.
Connect the 1/8 in. PFA tube labeled 5 (with blue band on quick connect
stem) from the Reference Bench interconnections box to the vacuum port on
the back of the AMH-38. The vacuum port is the bottom port of the two quick
connectors with a blue band. Press the quick connect stem into the
connector firmly until it clicks into place.
It is imperative that the mass loading shaft be fully threaded into the binary
mass tray. Be sure to use the T handled 3 mm allen wrench to tighten the
shaft to the end of the threads applying sufficient torque to cause the
mass load to rotate. Failure to fully screw in the shaft will cause
misalignment between the mass handler and the mass load that may cause
damage to the AMH-38 mass handler when operated.
Install the AMH-38 mass lifting shaft. Slip the threaded end of the shaft
down through hole in the center of the mass lifter (see Section 6.5.1, Figure
50). Thread the shaft into the binary mass carrier by holding and rotating the
trim mass tray. NOTE THAT SHAFT HAS A LEFT HAND THREAD SO IT
MUST BE ROTATED COUNTER-CLOCKWISE TO TIGHTEN IT. Use the T
handled, 3 mm allen wrench supplied in the AMH-38 accessories to tighten
the assembly. Tighten until you feel the mass start to rotate.
Level the PG7601 Platform using its two leveling feet and the level mounted
on the top of the AMH-38 mass handling system.
3.3.9.4 INSTALL THE REFERENCE VACUUM CDG ASSEMBLY
The PG7601 and FPG8601 reference vacuum CDGs are delivered with an
isolation valve connected to them. This valve is normally closed and serves
to maintain vacuum on the CDG at all times as exposing the CDG to
atmospheric pressure will cause zero shifts. New CDGs are shipped with
vacuum behind the isolation valve. Do not break the valve fittings or operate
the valve without establishing vacuum first.
Connect the PG7601 reference vacuum CDG assembly (CDG, valve, KF16 x
KF40 adaptor) to the KF40 port on the left (viewed from front) of the AMH-38
vacuum chamber. Use a KF40 centering ring and clamp. Install so that the
CDG body is in the vertical position.