Output Power Of Magnetron; Procedure For Measurement Of Microwave Energy Leakage - Samsung M308R Service Manual

Alignment and Adjustments

5-8 Output Power of Magnetron

PERSONNEL SHOULD NOT ALLOW EXPOSURE TO MICROWAVE RADIATION FROM MICROWAVE
GENERATOR OR OTHER PARTS CONDUCTING MICROWAVE ENERGY.
The output power of the magnetron can be measured by performing a water temperature rise test.
Equipment needed :
* Two 1-liter cylindrical borosilicate glass vessel (Outside diameter 190 mm)
* One glass thermometer with mercury column
NOTE: Check line voltage under load. Low voltage will lower the magnetron output. Make all temperature
and time tests with accurate equipment.
1. Fill the one liter glass vessel with water.
2. Stir water in glass vessel with thermometer, and record glass vessel's temperature ("T1", 10±1ûC).
3. After moving the water into another glass vessel, place it in the center of the cooking tray. Set the oven to high
power and operate for 86 seconds exactly. (3 seconds included as a holding time of magnetron oscillation:)
4. When heating is finished, stir the water again with the thermometer and measure the temperature ("T2").
5. Subtract T1 from T2. This will give you the water temperature rise. (DT)
6. The output power is obtained by the following formula;
Output Power =
7. Normal temperature rise for this model is 9ûC to 11ûC at 'HIGH'.
NOTE 1: Variations or errors in the test procedure will cause a variance in the temperature rise.
Additional power test should be made if temperature rise is marginal.
NOTE 2: Output power in watts is computed by multiplying the temperature rise (step E) by a factor of 50
times the of centigrade temperature.

5-9 Procedure for Measurement of Microwave Energy Leakage

1) Pour 275±15cc of 20±5ûC(68±9ûF) water in a beaker which is
graduated to 600cc, and place the beaker in the center of the oven.
2) Start to operate the oven and measure the leakage by using a
microwave energy survey meter.
3) Set survey meter with dual ranges to 2,450MHz.
4) When measuring the leakage, always use the 2 inch spacer
cone with the probe. Hold the probe perpendicular to the
cabinet door. Place the spacer cone of the probe on the door
and/or cabinet door seam and move along the seam, the door
viewing window and the exhaust openings moving the probe
in a clockwise direction at a rate of 1 inch/sec. If the leakage
testing of the cabinet door seam is taken near a corner of the door, keep the probe perpendicular to the
areas making sure that the probe end at the base of the cone does not get closer than 5cm to any metal. If it
gets closer than 5cm, erroneous readings may result.
5) Measured leakage must be less than 4mW/cm
Maximum allowable leakage is 5mW/cm
4mW/cm is used to allow for measurement and meter accuracy
2
5-3
MICROWAVE RADIATION
4.187 x 1000 x DT
83
CAUTION
83 : Heating Time (sec)
4.187 : Coefficient for Water
1000 : Water (cc)
DT : Temperature Rise (T2-T1)
2 , after repair or adjustment.
.
2
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