Output Power Of Magnetron - Samsung G639C Service Manual

Alignment and Adjustments

5-6 Output Power of Magnetron

PERSONNEL SHOULD NOT ALLOW EXPOSWRE 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 of 190mm)
* 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 one liter of water.
2. Stir water in glass vessel with thermometer and record glass vessel's temperature as T1. (10±1˚C)
3. After moving the water into another glass vessel, place it on the center of the cooking tray. Set the oven
to high power and operate for 54 seconds exactly. (2 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 rise as T2.
5. Subtract R1 from T2. This will give you the water temperature rise. (∆T)
6. The output power is obtained by the following formula;
Output Power =
7. Normal temperature rise for this model is 9˚C to 11˚C 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 power
factor of 91 in case of centigrade temperature.
5-7 Microwave Heat Distribution - Heat Evenness
The microwave heat distribution can be checked indirectly by measuring
the water temperature risen at certain positions in the oven :
1. Prepare five beakers made of 'Pyrex', having 100 milliliters capacity
each.
2. Measure exactly 100milliliters off water load with a measuring
cylinder and pour it into each beaker.
3. Measure the temperature of each water load.
(Readings shall be taken to the first place of decimals.)
4. Put each beaker in place on the cooking tray as illustrated in figure
below and start heating.
5. After heating for 2 minutes, measure the temperatures of water in each beaker.
6. Microwave heat distribution rate can be caicviated as follows :
Heat Distribution =
The result should exceed 65%.
5-3
MICROWAVE RADIATION
4.187 x 1000 x ∆T
52.3
Minimum
Temperature Rise
Maximum
Temperature Rise
CAUTION
52.3 : Heating Time (sec) * Output (W) = 100 x
4.187 : Coefficient for Water
1000 : Water (cc)
∆T : Temperature Rise (T2-T1)
X 100(%)
D
Beaker
D
D/4
D/4
D/4
D/4
Cooking Tray
Samsung Electronics
∆T