Cannon TE-BBR, Instruction & Operation Manual

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62 TE-BBR Instruction and Operation Manual
Clean Air Bearing Shaft and Load Cylinder in TE-BBR
If vertical movement of the Load Frame air bearing shaft is impeded, it may be due to asphalt
contamination at the top of the shaft, or other contaminants possibly introduced through the air lines to
the load cylinder. Do not attempt to lubricate the air bearing shaft. Lubricants can inhibit the function of
the air bearing. Use the following procedures to remove contaminants and debris.
Required Tools: Medium size Phillips screwdriver, asphalt solvent, 3/8” or adjustable wrench, petroleum
based (Stoddard® type) solvent
Remove Asphalt from the Shaft
Prepare the instrument for normal operation per manual instructions, including the section on
adjustment of gas pressure.
1. It is not necessary to prepare a beam or achieve a bath test temperature.
2. Carefully remove the Load Frame from the bath and place it on top of the Control Unit.
3. Adjust the ZERO regulator until the air bearing is lifted to the top of its travel.
4. Apply a small amount of asphalt solvent to an absorbent paper towel. Then gently wipe the air
bearing shaft beneath the load platform to remove asphalt from the shaft.
Caution: Do not apply lateral pressure to the air bearing as this may damage the
instrument.
5. Repeat step 4 until the air bearing moves freely. If movement of the shaft remains inhibited after
several repetitions, perform the load cylinder cleaning procedure in the next section of this technical
note.
Remove Load Cylinder Contaminants
Follow the procedure outlined in this section to remove contaminants that were introduced through the
twin air lines to the load cylinder.
1. Turn off instrument power at the rear of the TE-BBR Control Unit. Remove the Load Frame from the
bath and place it on top of the Control Unit.
2. Use the Phillips screwdriver to remove the four screws securing the front panel to the Load Frame.
3. Remove the front panel from the Load Frame.