H4-72-02-03
22
For internal use only
9.
Measuring the output power of the magnetron
The following procedure provides information on the working conditions of the magnetron but it
does not reproduce an accurate measurement of the microwave output power.
The test load is one litre (1000 ml) of water with a starting temperature of 15 - 24 °C in a container with
a capacity of 1000 ml. The use of a different amount of a different material may lead to a distortion of the
test results.
Proceed as follows to measure the output power:
1. Measure the voltage of the AC power and set the voltage to the correct value.
2. Remember that the test result is affected by the value of the supply voltage.
3. If the voltage is too high or too low, the test result is not accurate.
4. Place a container holding exactly 1000 ml of water at 15 - 24 °C in the centre of the microwave
oven.
5. Use an accurate thermometer to measure the exact starting temperature (T1).
6. Run the appliance for 63 seconds at maximum power.
7. At the end of this period quickly stir the water and read off the final temperature of the water. The
difference between the final temperature T2 and the initial temperature T1 represents the rise in
temperature.
Result:
The microwave output power of the appliance can be determined with the follow-
ing formula: P (W) = 70 x (T2 - T1)
If the output power is more than 15% of the nominal rating of the microwave oven,
the high-voltage capacitor and possibly also the magnetron must be replaced.
Determining the microwave output
The PAb output is determined by heating up a certain quantity of water (cold tap water).
Required:
• 2 vessels suitable for microwave ovens
each holding 1 litre.
• 1 thermometer with an immersion sensor.
Procedure:
1. Determine the initial temperature
(average).
2. Cooking time 2 min. at max. power.
3. Determine the final temperature
(average).
4. Calculate the difference in temperature.
5. Calculate the output.
2 min max output
