DH Instruments ADCS-601, Operation And Maintenance Manual

Page: 133 / 174

6. GENERAL MAINTENANCE AND ADJUSTMENTS
Page 121 © 2005 DH Instruments, Inc.
6.5.2 THE MASS SET
When removing the AMH and mass set, start by removing the AMH mass handler. See
Section 6.5.1.
PG7000 AMH masses are shipped in reusable, molded shipping and storage cases. One of
the cases contains the binary masses, binary mass carrier, mass bell and lifting shaft/trim
mass tray. The other cases contain the main masses of 6.4 kg (see Table 7 for mass set
parts list). Each mass is packed in a sealed plastic bag and then placed in a protective
shipping insert.
The stability over time of the PG7601 pressure measurements is a function of the
stability of the masses loaded on the piston. Precautions should be taken in handling the
masses to minimize influences that may change their mass. This includes always wearing
protective gloves when handling the masses to avoid contaminating them with body oils
and perspiration. Protective gloves are provided in the PG7601 accessory kit.
To install the AMH mass set, follow the order of operation below carefully (refer to Figure 51):
Prepare the masses: Open the shipping cases and remove all the masses and mass
set elements from their plastic bags.
Install the piston-cylinder module in the PG7601 Platform: See Section 6.6.2.
Install the binary mass carrier: Place the pyramidal shaped carrier on top of the piston cap.
Install the mass loading bell: Slip the mass loading bell over the binary mass carrier
and slide it down until the inside top of the bell sits on the binary mass carrier.
Install the main mass discs: Load the main mass discs (6.4 kg each) onto the mass
bell starting with mass #1 and loading in sequential order . Mass #1 should be at the
bottom of the stack and the highest number mass at the top. The mass sequence
numbers are laser marked on the top surface of each mass. Pass the mass disc over
and down the mass loading bell and center it on the ledge at the bottom of the bell. Load
the rest of the main masses, sequentially, onto the bottom mass.
Install the binary mass tubes: Load the binary mass tubes concentrically from the
largest to smallest, outside to inside. The largest, long tubes slip down between the main
mass stack and the bell and rest on the ledge at the bottom of the mass bell. The
smaller masses load onto the pyramidal steps of the binary mass carrier.
The mass loading process is complete: The mass set is in the all loaded position. The
mass lifting shaft/trim mass tray assembly is not yet installed. It will be attached after the
AMH automated mass handler is installed over the masses on the platform.