CHECKING FOR MICROWAVE ENERGY LEAKAGE
CAUTION
On every service call, checks for microwave energy emission must be made according to the following manner.
1.Remove the cooking rack from the oven cavity, if the microwave oven is so equipped.
2.Place a 275 ML (9. oz.) glass of water in the center of the oven bottom.
3.Select “HlGH” cook power, turn the mi- crowave oven on, and test for R.F. Ieakage using the following pattern:
a)Check around the cabinet at the front.
b)Check around the door.
c)Check across the console panel.
d)Check horizontally across the door
e)Check vertically across the door.
f)Check diagonally across the door.
g)Check across the air vents.
h)Check across the rear air vent.
NOTE: The scan speed is
EQUIPMENT
•Electromagnetic energy leakage monitor (NARDA 8100B, HOLADAY H1501).
•6100 cc glass beaker.
•Glass thermometer 100˚C or 212˚F.
When checking for R.F. Ieakage, use an ap- proved R.F. measuring device to assure less than 4 mw/cm2 emission at 5 cm distance with a maximum scan rate of 2.5 cm/second, in compliance with U.S. Government Department of Health, Education and Welfare 21 CFR1030, performance Standard for Microwave Ovens.
A properly operating door and seal assembly will normally register small emissions, but they must be no greater than 4 mw/cm2 to allow for measurement uncertainty.
NOTE: Enter leakage readings in the space BEFORE and AFTER on the service docu- ment.
All microwave ovens exceeding the emission level of 4 mw/cm2 must be reported to Dept. of Service for microwave ovens immediately and the owner should be told not to use the micro- wave oven until it has been repaired com- pletely.
If a microwave oven is found to operate with the door open, report to Dept. of Service, the manufacturer, and CDRH* immediately. Also tell the owner not to use the oven.
The interlock monitor switch acts as the final safety switch protecting the customer from microwave radiation. If the interlock monitor switch operates and opens the line fuse, the interlock switches have failed, and you must replace all of them (primary and secondary interlock switches, and the monitor switch), because their contacts may be melted and welded together.
All repairs must be performed so that micro- wave energy emissions are minimal.
*CDRH: Center for Device and Radiological health, food, and drug administration.
