Microwave Measurement - Sharp R-9570 Service Manual

MICROWAVE MEASUREMENT
After the adjustment of door interlock switches and door is
completed individually or collectively, the following leakage
test must be performed with a survey instrument and it must
be confirmed that the result meets the requirements of the per-
formance standard for microwave oven.
REQUIREMENT
The safety switch must prevent microwave radiation emission
in excess of 5mW/cm2 at any point 5cm or more from exter-
nal surface of the oven.
PREPARATION FOR THE 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
instrumentation as prescribed by the performance standard
for microwave ovens must be used for testing.
Place the turntable tray into the oven cavity.
Place the load of 275 f 15ml of water initially at 20 f 5OC
in the centre of the oven tray. The water container should
be a low form of 600ml beaker with inside diameter of ap-
prox. 8.5cm and made of an electrically nonconductive
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 leak-
age is measured accurately.
Close the door and turn the oven ON with the timer set for
several minutes. If the water begins to boil before the sur-
vey is completed, replace it with 275ml of the cool water.
3. Move the probe slowly (not faster than 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 the
oven.
Recommended instruments are:
NARDA 8 100
NARDA 8200
HOLADAY HI 1500
SIMPSON 380M
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