GMW 3470, Руководство пользователя

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Section 3
INSTALLATION
Cooling - continued
For recirculating cooling systems use distilled or deionized water with a biocide to prevent bacterial
growth and corrosion. Do not use corrosion inhibitors in high quality electrical systems since the
water conductivity is increased which can result in increased leakage currents and electrochemical
corrosion.
At currents of approximately 3.50A and below the Model 3470 can be operated safely without water
cooling. However the coil temperature will vary with the power dissipation. This results in
dimensional changes of the magnet yoke and air cooling is not suitable when high field stability is
required.
Freon, oil, ethylene glycol or other cooling mediums can be used. The flow required will be
approximately inversely proportional to their specific heats. An experimental determination of the
flow and pressure required will be necessary.
Avoid cooling the magnet below the dew point of the ambient air. Condensation may cause electrical
shorts and corrosion.
During operation the resistance can be checked using a voltmeter across each coil. The voltage will
rise to a constant value once thermal equilibrium has been reached. If it is desired to save water, the
flow can be reduced until the hot resistance is approached. NOTE: This adjustment must be made
slowly enough to allow for the thermal inertia of the coils.
3-3
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