Sharp R-4A52 Service Manual page 31

R -4A52
R-4E52
MICROWAVE MEASUREMENT
After adjustment of door latch switches, monitor
switch and door are completed individually or collec-
tively, the following leakage test must be performed
with a survey instrument and it must be confirmed that
the result meets the requirements of the performance
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 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 require-
ment for instrumentations as prescribed by the per-
formance standard for microwave ovens must be
used for testing.
Recommended instruments are:
NARDA 8100
NARDA 8200
HOLADAY HI 1500
SIMPSON 380M
2. Place the oven tray into the oven cavity.
3. Place the load of 275 +I 5ml of water initially at
20f5"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 im-
portant not only to protect the oven, but also to'in-
sure 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 meas-
ured at any point of 5cm or more from the external
surface of the oven.
Microwave leakage measurement at 5 cm distance
30