Post by ogeezer on Oct 14, 2006 4:47:47 GMT -6
Without a major investment in test equipment, the following test method is amazingly accurate for checking the wattage output: The temperature rise in 63 seconds, of 1 liter of water, (times 39) = the wattage output of the microwave oven.
HOW TO DO THE TEST:
Measure up exactly 1 liter of water in a microwaveable container (thick glass measuring cups tend to absorb more heat resulting in a lower reading). Let the container of water (preferably plastic) stand until the water measures room temperature on a accurate thermometer. Remove the thermometer and place the liter container of water in the microwave oven. Close the door and activate the microwave oven on High for 63 seconds. Immediately (be carefully) measure the temperature of the heated water. Subtract the water's original room temperature reading from the higher "heated" temperature reading. This will equal the temperature rise (Delta T). Now take the temperature rise and multiply it times 39. This figure will be the approximate output wattage of the oven. There should be a nameplate on the oven {{ Wattage Output 900 }} for example. Don't confuse this with the input power, which for 900 watts output will be about 1.5 KW input. Perform the test several times for an average, but don't be surprised if the reading is 150 watts lower than the nameplate. Remember a microwave oven is a Radio Frequency (RF)Transmitter commonly around 2450MHz (microwave band). This high of a microwave radio frequency causes the molecules of water, meat, etc. to vibrate and generate heat. The Magnetron RF Output Tube emissions (power out) will decrease with age. Professional servicing should be considered with reading consistently 400 watts below the oven's nameplate output rating.
I came across the above info reviewing an Owner-Builder publication at my employer's office & found it interesting. Hopefully you will too.
HOW TO DO THE TEST:
Measure up exactly 1 liter of water in a microwaveable container (thick glass measuring cups tend to absorb more heat resulting in a lower reading). Let the container of water (preferably plastic) stand until the water measures room temperature on a accurate thermometer. Remove the thermometer and place the liter container of water in the microwave oven. Close the door and activate the microwave oven on High for 63 seconds. Immediately (be carefully) measure the temperature of the heated water. Subtract the water's original room temperature reading from the higher "heated" temperature reading. This will equal the temperature rise (Delta T). Now take the temperature rise and multiply it times 39. This figure will be the approximate output wattage of the oven. There should be a nameplate on the oven {{ Wattage Output 900 }} for example. Don't confuse this with the input power, which for 900 watts output will be about 1.5 KW input. Perform the test several times for an average, but don't be surprised if the reading is 150 watts lower than the nameplate. Remember a microwave oven is a Radio Frequency (RF)Transmitter commonly around 2450MHz (microwave band). This high of a microwave radio frequency causes the molecules of water, meat, etc. to vibrate and generate heat. The Magnetron RF Output Tube emissions (power out) will decrease with age. Professional servicing should be considered with reading consistently 400 watts below the oven's nameplate output rating.
I came across the above info reviewing an Owner-Builder publication at my employer's office & found it interesting. Hopefully you will too.