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MEASUREMENT OF THE MICROWAVE OUTPUT POWER
Microwave output power can be checked by indirectly measuring the temperature rise of a certain amount of water exposed to the microwave as directed below. Procedure 1. Microwave power output measurement is made with the microwave oven supplied at rated voltage and operated at its maximum microwave power setting with a load of 1,000Â±5cc of potable water. 2. The water is contained in a cylindrical borosilicate glass vessel having a maximum material thickness of 3 mm and an outside diameter of approximately 190 mm. 3. The oven and the empty vessel are at ambient temperature prior to the start of the test. The initial temperature of the water is 10Â±2ËC(50Â±3.6ËF). It is measured immediately before the water is added to the vessel. After addition of the water to the vessel, the load is immediately placed on the center of the shelf which is in the lowest normal position. 4. Microwave power is switched on. 5. Heating time should be exactly 52(800W) and 47(900W) seconds. Heating time is measured while the microwave generator is operating at full power. The filament heat-up time for magnetrons is not included. 6. The initial and final water temperatures are selected so that the maximum defference between the ambient and final water temperature is 5K.
7. The microwave power output P in watts is calculated from the following formula: P = 4187 X â T/t â¢ â T is actual temperature rise. â¢ t is the heating time. The power measured should be 800WÂ±10%(G-36C5) and 900WÂ±10%(G-38C5). CAUTION : 1. Water load should be measured exactly to 1 liters. 2. Input power voltage should be exactly 230 volts as specified. 3. Ambient temperature should be 20Â±2ËC (68Â±3.6ËF)