12-14
Maintenance
Survey
Collar
Gasket
Be careful
not to bend
this plate
(p/n 9881-064)
Remove
these
screws
Foam
Seal
Gasket
The black rubber gasket is referred to as the Survey Collar Gasket; four spares are
included in the gasket kit under pn 6581-065. The white foam gaskets are referred
to as Foam Seal Gaskets; a package of 20 is included in the gasket kit under p/n's
8100-622 (kit) or 6560-229 (1 each).
The Foam Seal Gaskets can become cracked or lose their shape relatively quickly,
depending upon the conditions they are used in, and the pressure with which they
are placed over the soil collar. Inspect the foam seal gasket before you start
making measurements each day; if it appears that it might not form a tight seal
against the soil collar, you should replace it. The Survey Collar Gasket should not
need to be replaced unless it is torn.
To replace either the Survey Collar Gasket or the Foam Seal Gasket, you will need
to remove the thin metal plate that covers the Survey Collar Gasket. Be careful
with this plate - it is thin and can be bent easily. If the plate is bent or mishapen, it
will not seal properly.
To replace the Survey Collar and/or Foam Seal Gaskets, follow these steps:
1. Remove the 18 philips head screws from the metal plate on the bottom of the
Survey Chamber, as shown above. Remove the plate and set aside. Remove
the Survey Collar Gasket.
2. If you need to replace the Foam Seal Gasket, simply pry it out with a knife or a
screwdriver. Discard.
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