Sharp R-2V54 Service Manual page 7

R-2V54
TEST PROCEDURES (CONT'D)
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PROCEDURE
LETTER COMPONENT TEST
6. Measure the final water temperature. (Example: The final temperature T2 = 21 "C)
7. Calculate the microwave power output e in watts from above formula.
Initial temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Tl =
Temperature after (72 + 2)= 74 sec.
1 1 "C /
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . T2 =
Temperature difference Cold-Warm
21 "C
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Measured output power
AT1 = 10°C
/
The equation is "P= 60 x AT" . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P= 60 x 10°C = 600 Watts /
JUDGMENT: The measured output power should be at least +15 % of the rated
output power.
CAUTION: 1°C CORRESPONDS TO 60 WATTS. REPEAT MEASUREMENT IF THE POWER IS
INSUFFIClENT.
1 ooog
Heat up for 74 sec.
1 ooog
d5
3-w.
T2"C
MICROWAVE OUTPUT POWER (2 liter water load)
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 substitution, 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/4.2
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.
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/ The formula is as follows;
Pxt/4.2=VxAT P (W) = 4.2 x V x AT / t
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Our condition for the water load is as follows:
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Room temperature . . . . . . . . . . . . . . . . . . . . . around 20°C
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Water load . . . ...2000 ml
Initial temperature
Power supply Voltage . . . . . . . . . . . . . Rated
. . . . . . . 1 O&l "C
voltage
Heating time . . . . . . 2min. 48 sec.
/
P=50xAT
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Measuring method:
A) Use two 1 litre Pyrex beakers with a diameter of approximately of 12cms.
B) Place 1 litre of 10°C water in each beaker.
C) Mark Tl on the one beaker and mark 12 on the other one. And stir the water and measure the
temperature of water the thermometer and note them. The graduation of the thermometer must
be scaled by O.l"C at minimum and an accurate mercury thermometer is recommended.
D) Place the two beakers as touching each other in the centre of the cavity.
E) Set the timer to 2minute and 48 seconds at 100% power (the time required to raise the water
temperature 10 degrees C.)
F) The time must be measured with stopwatch or wristwatch.
G) After 2minute and 48 seconds stop the oven by opening the door.
H) Remove the two beakers from the oven and measure the temperature of the water by stiring the
water with the thermometer and noting the readings.
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