Microwave Measurement; Requirment; Preparation For The Testing - Sharp R-771 OE Service Manual

MICROWAVE MEASUREMENT

After the adjustment of the door interlock switches and
door is completed individually or collectively, the follow-
ing 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 micro
wave oven.
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
Before beginning the actual test for leakage, proceed as
Make sure that the test instrument is operating
1.
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.
Recommended instruments are:
NARDA 8 100
NARDA 8200
HOLADAY HI 1500
SIMPSON 380M
2. Place the turntable tray into the oven cavity.
3. Place the load of 275 rtl5ml of water with the
addition of one (1) percent by weight of sodium
chloride in solution initialy at 20 +5"C in the centre
of the over tray. The water container should be a low
form of 600ml 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 the cool salt water.
5. Move the probe slowly (not faster than 2.5cm/sec.)
along the gap.
6. The microwave radiation emission should be mea-
sured at any point of Scm or more from the external
surface of the oven.
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