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 5mW/cm.sq. 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
Center for Devices and Radiological Health
1390 Piccard Drive Rockville, Maryland 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 1mW/cm.sq. And always start measuring of an unknown field to assure safety for operating personnel from radiation leakage.
NOTE: The standard is 5mW/cm.sq. while in the customer’s home. 1mW/cm.sq. stated here is manufacturer’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 1000C
Figure 6
B. MEASURING MICROWAVE ENERGY LEAKAGE
(1)Pour 275
15cc of 20
5 ˚C water in a beaker which is graduated to 600 cc, and place the beaker in the center
of the oven.
(2)Set the energy leakage monitor to 2,450 MHz and use it following the manufacturer’s recommended test procedure to assure correct result.
(3)When measuring the leakage, always use the 2 inch (5 cm) 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. (See Figure 7)
Move probe along shaded area.
Probe scanning speed less than 2.5 cm/sec.
Figure 7
C.MEASUREMENT WITH THE OUT 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.
