DH Instruments FPG8601, Руководство по эксплуатации и обслуживанию

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8. GENERAL MAINTENANCE
Page 125 © 2007 DH Instruments, a Fluke Company
8.4 CALIBRATING THE INTERNAL CALIBRATION MASS
The internal calibration mass is used as a reference for the single point span adjustment performed
by the internal calibration process (see Section 5.3). The true mass of the internal calibration mass
is compared to the measured mass value to compensate for changes in span. This procedure explains
how to remove and replace the internal calibration mass and determine a new true mass value.
The active true mass value of the internal calibration mass can be viewed and changed using
[Tools]
,
[FPG Calibration Setup]
(see Section 6.6.3).
Determining the true mass value of the internal calibration mass is similar to any other true mass
determination. However, removing the internal calibration mass requires special knowledge of the FPG.
Please follow the steps in this section carefully to avoid damaging sensitive FPG components.
Table 45.
Vacuum Reference Zeroing Equipment List
EQUIPMENT
FPG Tools Software
M5 allen wrench
M3 allen wrench
Lint-free gloves
8.4.1 INITIAL PREPARATIONS
With FPG Tools is in
[Run Monitor]
mode, press the
[Shut Down]
button on the
functions toolbar (see section 5.9). Watch the status bar in FPG Tools for an indication
that the shutdown process is complete. In this state, the lubricating volume of the FPG is
at atmospheric pressure.
Press the down arrow icon on the functions toolbar in FPG Tools to lower the internal
calibration mass.
When the mass is lowered, turn power off on the FPG Terminal. View the counts display
on the
<Run Diagnostics>
form for an indication of when the mass is lowered. The
counts display should increase by a value equivalent to the mass of the internal
calibration mass.
8.4.2 REMOVE THE LOAD CELL COVER
Remove the six M6 SHC screws that mount the load cell cover to the load cell plate.
All six screws are accessed from the top of the load cell.
Facing the FPG, use two hands to grasp the sides of the load cell cover and lift with a
slight leftward motion. Lifting in this manner allows for the inside of the load cell cover to
be guided away from the load cell. Note that the load cell cover will be sliding up on the
internal heat sink that is located within the lubricating volume.
Carefully remove the load cell cover. The load cell can be irreparably damaged if the load
cell cover makes contact with the load cell.
Set the load cell cover aside on a flat and clean surface.
Remove the o-ring between the load cell cover and load cell plate.