R-962M - Sharp Home Appliance Service Manual (repair manual). Page 20

R-962M - 20

After any repair, the microwave oven must be checked for
microwave leakage to ensure continued safe operation. BS
EN 60335-2-25 specifies that the maximum permitted leak-
age with a load of 275 ml is 50 W/m

2 

(equivalent to 5 mW/cm

2)

at  a distance of 5 cm from the oven.

The following items are required to carry out this test:-
1.  A low form of 600 ml beaker made from an electrically

non-conductive material, such as glass or plastic, with an
inside diameter of approximately 8.5 cm. This must
contain 275 

±

 15 ml of water, at an initial temperature of

20 

±

 2˚C.

2. A leakage detector which has been calibrated within the

preceding 12 months to a stand whose accuracy  can be
traced to National Physical Laboratory Standards.

Recommended instruments are:

Apollo "XI"
Celtec "A100"

Before commencing the test, check that the leakage detector
is functioning and adjusted according to the manufacturer's
instructions, and any spacers are fitted to ensure that meas-
urement is taken 5cm from the surface of the oven.

1. Place the beaker containing the water load in the oven

cavity at the centre of the turntable. The placing of this
standard load in the oven is important, not only to protect
the oven, but also to ensure that any leakage it is not
disguised by too large a load absorbing energy.

2. Close the oven door, and with the power level set to

FULL, turn the oven ON with the timer set for a few
minutes operation. Should the water begin to boil before
the test has been completed, it should be replaced.

3. As shown in the diagram below, move the probe slowly

(not faster than 2.5 cm/sec.);-

a) around the edge of the door following the gap
b) across the face of the door
c) across any vents in the oven's sides, rear or top

Dotted line indicates the path taken by the leakage detector.

Whilst the maximum leakage permitted in BS EN 60335-2-25 is 50 W/m

2 

(equivalent to 5 mW/cm

2

), it is not normal to detect

any significant leakage, and therefore any detected leakage should be investigated.