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9. Adjust the height of each of the three CCR stand feet to simultaneously
accomplish the following:
a. The CCR stand is centered in the probe station stand with no part of the two
stands touching.
b. The CCR stand is level with equal weight placed on each of the three feet.
c. The spacing fixture can be placed on all four sides of the isolation bellows
with no more than a 2 mm (0.08 in) gap.
Pay attention to the appearance of the isolation bellows and the screws that secure
it. For proper alignment, the bellows should be straight, and should not appear
uneven. The opposing screws should be aligned directly above and below each other.
At the correct 58 mm height spacing, none of the connector feedthroughs on the
bottom of the vacuum chamber will touch the top of the vacuum shroud
(FIGURE 3-11).
The CCR stand must be properly positioned and leveled for the Model CRX-6.5K to
meet the published vibration specification.
10. Using the ¾ in wrench, lock the CCR stand feet locking nuts up against the
bottom of the CCR stand.
3.6.2 Connecting the
CCR Compressor to the
Probe Station
The flexible helium lines and electrical cable must be connected to the coldhead
located in the probe station and to the CCR compressor unit. Read the warnings and
cautions below prior to following the steps to make these connections.
The CCR (cold head, compressor, and flexible helium lines) contain high pressure
(1.86 MPA (270 psig) helium gas. Hitting the equipment with a sharp edge or pointed
object may cause explosion or escape of gas.
The minimum bend radius of the flexible helium lines is 180 mm (9 in). Bending the flexible
helium lines at a smaller angle may cause explosion or escape of gas.
Inspect the flat rubber gasket of the flexible helium line connections at both the cold head
and the compressor unit for dirt, dust, and proper fitting before connecting the flexible
lines. Connection of the lines with abnormal fitting may cause escape of the helium gas.
With the connection of both flexible helium lines to the compressor unit, always connect
the return line first and then the supply line. The opposite order may cause mis-operation.
FIGURE 3-11
Proper alignment as shown: bellows straight,
screws aligned and spacer in place