Microwave Measurement - Sharp R-90GCH Service Manual

CPU unit
6. Remove the two (2) screws holding the panel angle to
the panel sub assembly.
7. Release the panel angle from the two (2) tabs of the
panel sub assembly first.
8. Pull out the panel angle from the panel sub assembly
and remove it.
9. Remove the twenty-two (22) screws holding the CUP
unit to the panel sub assembly.
10.Now, the CPU unit is free.
NOTE: After the panel angle is removed from the
panel sub assembly, it is can be found that the
bottom side of the panel sub assembly is
After adjustment of secondary interlock switch, monitor
switch, 3rd. latch switch, door sensing switch and door are
completed individually or collectively, the following leak-
age test must be performed with a survey instrument and
it must be confirmed that the result meets the require-
ments of the performance standard for microwave oven.
REQUIREMENT
The safety switch must prevent microwave radiation emis-
sion in excess of 5mW/cm
external surface of the oven.
PREPARATION FOR TESTING:
Before beginning the actual test for leakage, proceed as
follows;
1. Make sure that the test instrument is operating normally
as specified in its instruction booklet.
Important:
Survey instruments that comply with the requirement
for instrumentations as prescribed by the performance
standard for microwave ovens must be used for testing.
Recommended instruments are:
NARDA 8100
NARDA 8200
HOLADAY HI 1500
SIMPSON 380M

MICROWAVE MEASUREMENT

2 at any point 5cm or more from
2
mW cm
2
mW cm
melted and transformed by heat. But it is not
abnormal and no problem to use the oven.
Panel angl
Screw
Figure C-6. Panel Angle Removal
2. Place the oven tray into the oven cavity.
3. Place the load of 275 ± 15ml of water initially at 20
± 5˚C in the centre of the oven tray. The water
container should be a low form of 600 ml beaker with
inside diameter of approx. 8.5cm and made of an
electrically non-conductive material such as glass
or plastic.
The placing of this standard load in the oven is important
not only to protect the oven, but also to insure that any
leakage is measured accurately.
4. Close the door and turn the oven ON with the timer set
for several minutes. If the water begins to boil before
the survey is completed, replace it with 275ml of cool
water.
5. Move the probe slowly (not faster that 2.5cm/sec.)
along the gap.
6. The microwave radiation emission should be measured
at any point of 5cm or more from the external surface
of the oven.
Microwave leakage measurement at 5 cm distance
35
Screw
Bottom side of
panel sub assembly
Tabs
Panel sub assembly
R-90GCH