LRS Micro-g LaCoste FG5, Manual, Page: 39 / 149

How to Set Up and Run the FG5
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pressure on the travel lock mechanism. While holding this position, pull out
the brass knob, rotate it 90° in either direction, and gently release it so the pin
in the shaft rests in the lock. Gently release the wrench or ball driver from the
motor shaft.
3.1.5.ION PUMP
(If the ion pump is already on and maintaining the chamber vacuum, skip to step
to “Leveling the Dropping Chamber” below)
24. Recheck the AC, BAT, and HV switches on the ion pump power supply, and
make sure they are off.
25. Connect the ion pump HV cable to the ceramic connector on the pump.
Connect the small green safety ground umbilical of the HV cable to one of the
banana jacks located on the base of the dropping chamber near one of the
handles. Connect the safety HV ground to the other banana jack on the base
of the dropper. Tie both cables to a tripod leg with a velcro strap.
26. If the vacuum in the dropping chamber has remained intact since the
previous use, the ion pump alone may be sufficient to pump down the
chamber. The ion pump will probably start if it has been off for two hours or
less. Appendix B discusses the use of the turbo pump.
27. Before turning on the ion pump, set the front panel meter select knob to
PUMP VOLTAGE (kV) . Turn on the pump and check the meter. The
voltage should be at least 2 kV within 5 minutes after turning on the ion
pump. An
increasing voltage usually indicates that the ion pump is starting.
Nominal voltages (at operating pressure) are:
4 kV on AC
3 kV on battery power
28. If the ion pump does not start within 5 minutes, shut off the power at the ion
pump power supply, and prepare to pump the dropping chamber with the
turbo pump. See appendix B for instructions.
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