| Bibliographic Entry | Result (w/surrounding text) |
Standardized Result |
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| SHARP Household Microwave Oven Model R-5A50. Assembled in USA of parts made in USA and Imports. Serial No.159776 Manufactured November 1988. SHARP Electronics Corp. MAHWAH NJ 07430. | "12. V.A.C. 7.44 kW 60 Hz Single Phase Output 700 W 2450 MHz. Complies with DHHS Radiation Performance Standards 21CFR Subchapter J." | 5.8 A | |||||||||||||||||
| Microwave Oven. Encyclopedia.com. 2004. | "Typical output power for consumer devices ranges from 650 to 1200 watts." | 5.4–10 A | |||||||||||||||||
| Davidson, Homer L. Troubleshooting & Repairing Microwave Ovens USA: McGraw-Hill, 1997: 62. | "A home oven should have a reading between 1.6 kV and 4.5 kV (equals 160–450 mA.), while commercial ovens have a higher measurement. The voltage might vary from 2.0 kV to 7.0 kV (200–700 mA) of the current. Any oven that reads above these figures indicate a leaky or shorted magnetron tube (Table 2-1)." | 0.160–0.700 A (magnetron tube only) |
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0.160–0.270 A (magnetron tube only) |
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| Sprague, Dewey D. A Practical Approach to Microwave Oven Safety. Health Physics Society. 2004. | "The high-voltage electrical components (up to 4,000 V DC at 300 mA) are contained in a grounded metal enclosure." | 0.300 A (magnetron tube only) |
Microwave ovens can be found in practically every American household. It is a fast and easy device for reheating food. Though so many people own a microwave, do they know how one works?
Microwave ovens use radio waves with a frequency of about 2,500 megahertz to heat food. Water, fats and sugars absorb these radio waves, changing them into heat. One weird thing about radio waves is that not every material will absorb the waves equally. A lot of plastics, glass or ceramics won't absorb them. Metal doesn't work well because it reflects radio waves. This is why conductors are not put in the microwave. Sparking can occur and this could lead to something being burned. My parents used to say, "Uh yeah… that's supposed to happen. It means it's working." So unlike what my parents and probably many American thought when they first purchased a microwave, they can't just stick any container in the microwave oven and expect it to work.
Microwave ovens consume power at a rate of 650–1200 watts, which corresponds to a current of 5.4–10 amps at 120 volts AC. To convert power to current, use the equation…
P = VI
It is stated that if electrical components with voltage up to 4,000 V DC at 300 mA are in contained in grounded metal, then the component is safe to use. Does this go for all microwave ovens, new and old? A reading higher than these numbers means that there may be a leakage, which isn't a good thing and it might not be safe. But then again, how safe are microwave ovens? Is the normal current itself safe? If so, why am I told that to be safe, I should stand far enough away while a microwave is on? (Courtesy of my Earth Science teacher who made the entire class paranoid.)
Anna Ng -- 2004