Measuring RF Leakage for Microwave
Safety
WARNING: This procedure requires work
with hot surfaces and water loads. To avoid
burns, be careful when testing.
An RF (microwave) leakage test must be performed
at the conclusion of the following service tasks:
• Door removal, replacement and/or adjustment
• Waveguide removal and/or replacement
• Magnetron removal and/or replacement
• Door switch adjustment and/or replacement
WARNING: If the unit fails the microwave
leakage test (leakage greater than 5mW/cm2),
the oven must be taken out of service
immediately until the defect is corrected. In
addition, the CDRH Regulation 21 Subpart
C, 1002.20 requires that leakage readings
of over 5mW/cm2 must be reported to the
manufacturer.
To Measure RF Leakage
1. Turn the oven on (page 7) and allow it to warm
up to the set temperature (approximately 15
minutes if the oven starts cold).
2. Once the oven has warmed up, ready the oven
for the test:
a. Place the oven in manual mode (page 11).
b. From manual mode, create a 1 minute
recipe with a single event, 10% air, and
30% microwave.
3. Place a water load into the cook cavity. The
water load must conform to the following
specifications:
• Volume: 275 ml ± 15 ml
• Temperature: 68ºF ± 9ºF (20ºC ± 5ºC)
• Vessel: Pyrex dish capable of 500º F
4. Close the oven door and press the Cook key.
The microwave system will turn on.
5. Measure microwave emission around the door
slowly as shown in Figure 76, moving the meter
sensor at 0.5 inches/second.
6. As microwave leakage is observed while moving
the sensor, note any meter spike areas that come
close to 5mW/cm2 for later re-measurement.
7. Replace the water load every 60 seconds until
the test is completed, and also after scanning
the door.
8. Close the oven door and return the meter probe
to any “meter spike” areas and allow the probe
to remain in the “spike” area for 17 seconds.
Note the highest reading obtained.
NOTE: There may be several places on the door
where this procedure needs to be done. If so, start
out with a fresh water load each time a new area is
measured, or if measurement of an area takes longer
than 60 seconds.
9. After each test is complete, open the oven door
and dispose of the hot water. Let the steam
dissipate with the door open.
Troubleshooting
The following faults may occur in relation to the
oven door:
• F3: Magnetron Current Low (see page 49)
• F4: Monitor (see page 50)
The following issues may occur in relation to the
oven door:
• “Cook Door Open” message when door is closed
(see page 54)
Figure 76: Survey Meter Placement
OVEN SYSTEMS36
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