Thermocouple Replacement And Position Adjustment; Cleaning Bus Bar Contacts - PAC Alcor JFTOT II Manual

8. While viewing the initial AutoCal display
"PERFORM CALIBRATION?" press F1
(remove stuck thermocouple) to apply power
to melt the Lead. When the Lead has melted,
raise the thermocouple to remove it from the
Lead. The JFTOT will turn the heater off
and display the initial AutoCal screen. Clean
the tip of the thermocouple to remove any
Lead. Let the AutoCal Calibrator cool, then
remove.
3.3 THERMOCOUPLE REPLACEMENT
AND POSITION ADJUSTMENT
1. The thermocouple used for measuring and
controlling the temperature of the JFTOT
heater tube needs to be replaced when
damaged.
2. To remove the thermocouple, adjust the
thermocouple slide scale position to the top of
the scale then unplug the thermocouple.
3. Plug a new thermocouple into the slide
assembly socket. The thermocouple plug is
polarized and will fit into the socket only one
way.
4. Adjust the top of the slide assembly so that it
is even with the top of the reference mark on
the scale (top of the scale). The tip of the
thermocouple must be flush with the top of
the upper bus bar. If required, loosen the
socket adjustment screw, properly position
the thermocouple tip, and then re-tighten the
socket adjustment screw.
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3.4 CLEANING BUS BAR CONTACTS

1. The contact area of the bus bars are gold
plated and must be kept clean. During a test,
about 200 A current passes through the
contact area to heat the heater tube.
2. Before every test, use a tissue soaked with
solvent to clean the gold contact area.
3. Once a year or after every 50 tests, use an
Art Gum type eraser (very soft) and lightly
rub the gold contact area to remove dirt and
oxide.
CAUTION - DO NOT use hard erasers, emery
paper or other abrasive material to clean the
contact area, since they will remove the gold
plating.
JFTOT II Mainenance Manual Rev. C