R-2V53
TEST PROCEDURES
PROCEDURE
LETTER COMPONENT TEST
MAGNETRON TEST
NEVER TOUCH ANY PART IN THE CIRCUIT WlTH YOUR HAND OR AN INSULATED !
; TOOL WHILE THE OVEN IS IN OPERATION.
CARRY OUT 3D CHECKS
Isolate the magnetron from the high voltage circuit by removing all leads connected to the filament
terminal.
To test for an open circuit filament use an ohmmeter to make a continuity test between the
magnetron filament terminals, the meter should show a reading of less than 1 ohm.
To test for a short circuit filamen to anode condition, connect ohmmeter between one of the fil-
ament terminals and the case of the magnetron (ground). This test should be indicated an infinite
resistance. If a low or zero resistance reading is obtained then the magnetron should be replaced.
MICROWAVE OUTPUT POWER BY METHOD OF IEC 705 1988
The following test procedure should be carried out with the microwave oven in a fully assembled
condition (with outer case fitted).
Microwave output power from the magnetron can be measured by way of IEC 705, i.e. it can be
measured by using a water load how much it can be absorbed by the water load. To measure the
microwave output power in the microwave oven, the relation of calorie and watt is used.
When P(W) heating works for t(second), approximately P x t/4.1 87 calorie is generated. On the
other hand, if the temperature of the water with V(ml) rises AT (“C) during this microwave
heating period, the calorie of the water is V x AT. ,
The formular is as follows;
Pxt/4.187=VxAT
P(W)=4.187xVxAT/t
Our condition for the water load is as follows:
Room temperature ... around 2O”C, Power supply Voltage ... 240 volts.
Water load ... 1000 g, Initial temperature ... 1Of2”C, Heating time .... 70 sec.
P=60xAT
Measuring condition:
I. Container
The water container must be a cylindrical borosilicate glass vessel having a maximum material
thickness of 3 mm and an outside diameter of approximately 190 mm.
2. Temperature of the oven and vessel
The oven and the empty vessel are at ambient temperature prior to the start of the test.
3. Temperature of the water
The initial temperature of the water is (10 f 2)X.
4. Select the initial and final water temperature so that the maximum difference between the final
water temperature and the ambient temperature is 5K.
5. Select stirring devices and measuring instruments in order to minimize addition or removal of
heat.
6. The graduation of the thermometer must be scaled by 0.1 “C at minimum and an accurate
thermometer.
7. The water load must be (1000 f 5) g.
8. “t” is measured while the microwave generator is operating at full power. Magnetron filament
heat-up time is not included.
NOTE: The operation time of the microwave oven is “t + 2” sec. 2 sec. is magnetron filament
heat-up time.