Bird Technologies 8640B Series - Manual (Page 26)

Maintenance
15
y Turn off the RF power and interlock circuitry.
y Disconnect the RF line.
y Connect the multimeter test leads to the center and outer
conductor of the load. Refer to Figure 6.
y Compare the measured value with the previous measurement and
with the baseline resistance, measured when the load was put
into service. If the new value differs from either of these by more
than 2 ohms this could indicate a failing resistor.
Coolant
Changing Coolant
Follow these instructions to change the coolant. To just add coolant,
go to step 5. To just drain the coolant, follow steps 1 – 4.
Figure 6
Measuring
Resistance
WARNING
Never attempt to connect or disconnect RF equipment from the
transmission line while RF power is being applied.
Leaking RF energy is a potential health hazard.
WARNING
Ethylene glycol is toxic. Do not take internally. Avoid contact with
eyes, skin, and clothing. Avoid breathing vapor. Wash thoroughly
after handling.
CAUTION
Use only distilled water or the supplied ethylene glycol as coolant.
Do not use tap water, automotive antifreeze, sealants, or leak
stopping material. Use of these materials will damage the
instrument and void all warranties.
CAUTION
Operation without sufficient coolant can damage the unit.