Goldstar MV-1155W, Service Manual

Page: 13 / 48

8. PROCEDURE FOR MEASURING
MICROWAVE ENERGY LEAKAGE
A. CAUTIONS
(1) Be sure to check a microwave emission prior to
servicing the oven if the oven is operative prior to
servicing.
(2) The service personnel should inform the
manufacturer, importer or assembler of any certified
oven unit found to have a microwave emission level
in excess of 4 mW/cm
2
and should repair any unit
found to have excessive emission levels at no cost to
the owner and should ascertain the cause of the
excessive leakage. The service personnel should
instruct the owner not to use the unit until the oven
has been brought into compliance.
(3) If the oven operates with the door open, the service
personnel should;
— Tell the user not to operate the oven.
— Contact the manufacturer and CDRH (Center for
Devices and Radiological Health) immediately.
NOTE: Address on CDRH
Office of Compliance (HFZ-312)
Center for Devices and Radiological Health
1390 Piccard Drive
Rockville, Marryland 20850
(4) The service personnel should check all surface and
vent openings for microwave emission testing.
(5) Check for microwave energy leakage after every
servicing. The power density of the microwave
radiation leakage emitted by the microwave oven
should not exceed 4 mW/cm
2 . And always start
measuring of an unknown field to assure safety for
operating personnel from radiation leakage.
NOTE: The standard is 5 mW/cm
2 . while in the
customer's home. 4 mW/cm 2 . stated here is
manufactruer's own voluntary standard for units in
customer's home.
EQUIPMENT
●
Electromagnetic energy leakage monitor
(NARDA 8100B, HOLADAY HI-1501).
●
600cc glass beaker.
●
Glass thermometer 100°C.
B. MEASURING MICROWAVE ENERGY LEAKAGE
(1) Pour 275
±
15cc of 20
±
5°C water in a beaker which
is graduated to 600cc, and place the beaker in the
center of the oven.
(2) Set the energy leakage monitor to 2,450MHz and
use it following the manufacturer's recommended
test procedure to assure correct result.
(3) When measuring the leakage, always use the 2 inch
(5cm) spacer supplied with the probe.
(4) Operate the oven at its maximum output.
(5) Measure the microwave radiation using and
electromagnetic radiation monitor by holding the
probe perpendicular to the surface being measured.
Figure 6
C. MEASUREMENT WITH THE OUTER CASE
REMOVED
(1) When you replace the magnetron, measure for
microwave energy leakage before the outer case is
installed and after all necessary components are
replaced or adjusted.
Special care should be taken in measuring the
following parts.
— Around the magnetron
— The waveguide
WARNING: AVOID CONTACTING ANY HIGH
VOLTAGE PARTS.
— 11 —
Move probe along shaded area.
Probe scanning speed
less than 2.5cm/sec.
Figure 5