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Maintenance
Maintenance
Bob Shaft
Before performing any type of maintenance, be sure and unplug the power
supply and bleed off all Nitrogen. Also, be careful not to bend the bob shaft
and thermocouple.
When working with bearings, be careful not to handle them with your bare
hands. The oil from your skin can contaminate the bearing.
A good indicator that maintenance is required is if the r^2C value is less
than .9990 (refer to page 18 for more information). If a calibration check
using certified calibration fluid shows viscosity readings that are not linear
at multiple shear rates, this can also indicate a problem that requires
maintenance.
1. Unplug the viscometer from the electrical source.
2. Gently turn the bob counterclockwise to remove it from the bob shaft.
Be very careful to keep the thermocouple straight. A bent
thermocouple will cause inaccurate readings. Pull the bob straight
down slowly.
3. Unscrew the expansion joint.
Remember to hold the rotor tube in place as described in steps 8 - 11 on
4. Remove the top panel.
5. Unplug the thermocouple and the grey cable that runs into the top of the
transducer cap.
6. Unscrew the eight allen bolts from the transducer cap. Be careful not to
drop the Allen bolts into the viscometer. Remove the transducer cap and
set it aside.
Be very careful to keep the thermocouple straight. A bent
thermocouple will cause inaccurate readings.