Unusual Operating Conditions; Low Current; High Current - Agilent Technologies Varian 913-0037 Bedienungshandbuch

UNUSUAL OPERATING CONDITIONS

Low current

If the pump current reads lower than normal for the
pressure (see the preceding figure), the discharge
may have been extinguished.
To check for the pump being "out of strike" (dis-
charge extinguished), remove the magnet and ob-
serve the residual current. If the current is the
same with and without the magnet in place, no
discharge exists in the pump.
a) To restart the discharge, tap the pump body
with a soft plastic tool, or heat the pump body
locally with a small soldering iron. This should
liberate surface gas within the pump and re-
start the discharge. NEVER strike the pump
with metal hand tools.
b) If the magnet strength is below its rated level,
the pump discharge and speed will be reduced
and the discharge may extinguish at a pres-
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sure below 1x10 Torr.

High current

If the pump current reads higher than normal for
the pressure (see the preceding figure), look for:
a) Breakdown of the connecting high-voltage ca-
ble. Repair or replace.
b) Ohmic breakdown in the control unit. Repair
according to the control unit instruction man-
ual.
c) Shorting of anode support insulators, caused
by a flake of titanium compound. Tapping the
pump, as described in step a) of the preceding
paragraph, may correct this condition.
d) Field emission current from fine whiskers
formed on the pump cathodes. Hi-pot the
pump by applying 10 to 14 kVac at 20 to 30
mA for 5 to 20 seconds.
e) Coatings on the insulators caused by operat-
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ing above 10 Torr for extended periods.
Since disassembly of the pump is not practi-
cable, this condition must be regarded as a
life-limiting factor. Avoid operating the pump at
high pressures for long periods.
Meaning of the "WEEE" logo found in labels
The following symbol is applied in accordance with
the EC WEEE (Waste Electrical and Electronic
Equipment) Directive.
This symbol (valid only in countries of the
European Community) indicates that the product
it applies to must NOT be disposed of together
with ordinary domestic or industrial waste but must
be sent to a differentiated waste collection system.
The end user is therefore invited to contact the
supplier of the device, whether the Parent Com-
pany or a retailer, to initiate the collection and dis-
posal process after checking the contractual terms
and conditions of sale.
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INSTRUCTIONS FOR USE
DISPOSAL
87-400-085-01(D)