When compared to other types of radiation, microwaves fall between radio waves, which tend to be longer, and infrared waves, which are shorter. What makes microwaves so specialized for cooking is just how they interact with water molecules.
Inside microwave ovens, the microwaves are created using a device called a magnetron. At their core, magnetrons are high-voltage motors that output energy in the form of microwaves rather than mechanical work. Inside the microwave oven, a transformer steps up electricity from the wall socket, V in the US, or V in Europe, to around volts.
This increased voltage is needed to power the magnetron, causing a filament to heat up at the core of the device. As this filament heats up, electrons are released. The microwave oven puts these electrons to work. A circular magnet is located near the heated filament. Normally, the electrons that are released by the filament would become attracted to the anode, but because of the positioning of the magnet, the electrons loop back to the filament itself.
This looping of electrons is what actually creates microwaves. All of that may have sounded a little bit complex, and it can be when explained without diagrams. For a deeper dive into the understanding of how magnetrons and, ultimately, microwaves work, take a look at the video below. One popular myth about microwaves is that they can give you cancer. This may stem from the use of the word 'radiation' in describing how they work, as well as a fear that this microwave radiation can leak out of the microwave.
For more safety recommendations see the section of this page titled: Tips on Safe Microwave Oven Operation. Most injuries related to microwave ovens are the result of heat-related burns from hot containers, overheated foods, or exploding liquids. Most injuries are not radiation-related. That said, there have been very rare instances of radiation injury due to unusual circumstances or improper servicing. In general, microwave oven radiation injuries are caused by exposure to large amounts of microwave radiation leaking through openings such as gaps in the microwave oven seals.
However, FDA regulations require that microwave ovens are designed to prevent these high level radiation leaks. At one time there was concern that radiation leakage from microwave ovens could interfere with certain electronic cardiac pacemakers.
Similar concerns were raised about pacemaker interference from electric shavers, auto ignition systems, and other electronic products. However, patients with pacemakers are encouraged to consult their physicians if they have concerns. There is little cause for concern about excess microwaves leaking from ovens unless the door hinges, latch, or seals are damaged. The FDA also monitors appliances for radiation safety issues and has received reports of microwave ovens that appear to stay on — and operate — while the door is open.
When operating as intended, microwave ovens have safety features to prevent them from continuing to generate microwaves if the door is open.
However, if an oven does continue to operate with the door open, consumers cannot be percent sure that microwave radiation is not being emitted. Thus, if this occurs, the FDA recommends immediately discontinuing use of the oven.
If you suspect a radiation safety problem with your microwave oven, you may contact the microwave oven manufacturer. Manufacturers who discover that any microwave ovens produced, assembled, or imported by them have a defect or fail to comply with an applicable Federal standard are required to immediately notify FDA.
You may also report any suspected radiation-related problems or injuries to the FDA by completing and mailing the Accidental Radiation Occurrence Report form. What is Microwave Radiation? Cooking with Microwaves Microwaves are produced inside the oven by an electron tube called a magnetron. Avoiding Injuries from Super-Heated Water in Microwave Ovens The FDA received reports in the past of serious skin burns or scalding injuries around people's hands and faces as a result of hot water erupting out of a cup after it had been overheated in a microwave oven.
Microwave Ovens and Health Microwave radiation can heat body tissue the same way it heats food. The radiation is harmful mostly to the parts of the body that cannot conduct the heat away very effectivelythe eyes especially.
I think that heat transfer could explain why one sometimes hears about people fast-food workers, for instance getting headaches when exposed to leaking microwave ovens. Hintenlang, associate professor nuclear and radiological engineering at the University of Florida at Gainesville, adds some further details: "Microwave ovens cook food by generating intermolecular friction between the molecules of the food.
The microwaves cause water molecules to vibrate; the increased friction between the molecules results in heat. Microwaves could affect your tissue in a similar way if they were able to escape from the microwave oven. Modern microwave ovens are designed to allow essentially no leakage of microwaves, however. The microwave used for cooking is about 12 centimeters from crest to crest, says Louis Bloomfield, a professor of physics at the University of Virginia.
At this wavelength, microwaves are readily absorbed by most foods. But the particles in a microwave, known as photons, don't have enough energy to damage molecules and cause cancer like ultraviolet rays or X-rays. A component called the magnetron generates microwaves from electricity inside the microwave oven. To power the magnetron, a transformer converts the standard household electricity from a wall socket of volts to about 4, volts or higher.
The voltage heats a filament at the center of the magnetron, boiling off electrons. Most microwaves have a glass turntable that moves the food around like a carousel so that it heats evenly.
If the food wasn't being rotated, parts of your meal would get stuck in the microwave's hot and cold spots. When you hit the start button "it usually takes about 2 seconds to heat up a filament inside the magnetron tube," says Schiffmann.
The microwaves are then blasted into the food compartment. The commonly used frequency of microwaves, 2.
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