If you think of an appliance that has transformed modern kitchens, it must be the microwave oven. Its primary usage was for heating foods. Read this article to find out how does a microwave oven work.
The microwave oven is helpful for time-consuming activities. Such as melting butter or heating water. It is now most common in homes and the office, although its initial usage was in commercial kitchens.
How was the microwave oven invented?
During the second world war, while walking past a microwave radar. American engineer Percy Spencer noticed that the chocolate bar melted in his pocket.
He thought that the microwave coming from magnetrons could chase enemies in a battle. It could also cook pasta as well.
This discovery was delightful; it was innovative but accidental. Spencer’s first food item, then fried with microwaves, was popcorn.
An egg was what he tried next without putting it over the fire. From a distance, as if something magical has happened. The moment was historical, without any doubt.
Our ancestors would’ve loved the microwave ovens! They could have thrown everything in the microwave oven, pushed a few buttons. Got a meal ready in a minute or two instead of resting around smoky wood flames for hours. Getting the buffalo stew ready for their stone-age mates.
The impact of microwave ovens in households
The invention raised household comfort to a new level. When microwave ovens became popular in the 1970s. A conventional oven heats food from the outside. But to cook food, a microwave oven uses small, high-powered electromagnetic waves.
This way, a microwave oven can cook food such as a meat joint six times faster than a conventional one.
Microwave ovens often save electricity. Without waiting for the oven to heat up to a high temperature first, you can cook. Let’s take a closer look at the way it works!
There’s an enormous application of science and engineering behind microwaves. But we can break it down into simple bits to grasp and digest.
How does it work?
Microwave oven operates by producing radiation, which passes through the food. Microwaves are not unique to microwave ovens. They are electromagnetic waves with a frequency that ranges between 300 MHz and 300 GHz.
Usually, microwave ovens use a frequency of 2450 MHz (a 12.24 cm wavelength).
What’s inside the oven?
There is a microwave generator inside the strong metal case called a magnetron. The magnetron takes energy from the power outlet when you start to cook food. Then transforms it into high-powered, 12 cm (4.7 inches) radio waves.
Using a channel called a waveguide. The magnetron blast the waves into the food compartment. The food is on a turntable, rotating around so that the microwaves cook it.
Inside the microwave oven, a part called the magnetron produces microwaves from electricity. A transformer transforms standard household electricity from a wall socket. From 120 volts to 4,000 volts or higher to power the magnetron.
In the middle of the magnetron, the voltage heats a filament, boiling off electrons. As the filament heats up, it releases electrons. The electrons will rush out toward an anode or positive terminal. Surrounding the filament in a straight line.
Still, two ring magnets bend the electrons back toward the filament. Above and below the anode and travel around in a circular path.
At a frequency of 2450 MHz, a domestic microwave oven runs with a power ranging from 500 to 1100 watts. An electronic tube called a magnetron generates a microwave.
The microwaves spread in the oven cavity once the oven is on. It then gets mirrored by a stirrer fan to distribute the microwaves in all directions. The metal sides of the oven cavity reflect them, and the food absorbs them.
How is the heat used?
By keeping the food in a revolving turntable inside the oven. The heat can enter it from a uniform direction. When they consume microwave energy, water molecules in the food vibrate. The friction between the water molecules results in heating that cooks the food.
Unlike regular ovens, only the food absorbs microwave radiation. The surrounding oven cavity doesn’t. It is best to use the dishes and containers designed for cooking in microwave ovens.
When overheated, some materials, such as plastics, are not suitable for microwave ovens. It can melt or burst into flames.
Microwaves do not heat food containers intended for cooking in the microwave. These materials get warm from being in touch with the hot food.
It is the energy field that emerges from microwave ovens and other devices. Microwave radiation consists of long, narrow radio waves with high-frequency. It is generally beyond the human sensory scope.
Like other electromagnetic waves except for visible light. Microwaves are invisible to the human eye. Microwaves are unnoticeable to the human eye. They are harmful to humans’ health for prolonged exposure.
How much is radiated by the ones at home?
The amount of radiation emitted by microwave ovens varies depending on their wattage. Microwave is also a type of electromagnetic radiation with different frequencies. Ranging from one gigahertz to one thousand gigahertz.
The above definition encompasses both UHF and EHF channels. But, UHF waves generally associates with lower frequencies. Also less severe effects on our health than EHF. These shortwaves produce less acute physical injuries.
Although microwave ovens emit in all directions. They have the most impact when the microwaves have reflected the device. The deflection is due to the microwave ovens’ focusing effect on air molecules that are in motion.
The effects of microwave radiation vary according to the frequencies of the waves.
Some microwaves generate heat which may cause burns. Other microwave ovens generate sound waves that may produce inner ear discomfort. Moreover, some microwave ovens have harmful gamma rays.
Is microwave radiation from ovens harmful?
Although microwave ovens are safe. Their use may bring some negative health issues like headaches, nausea, and stress. Long-term exposure to microwaves can also cause skin cancer.
Since microwave ovens emit heat in all directions. It may generate effects like uneven heating of one area by damaging a nearby part.
When this happens, it can cause burns or injury to people or even property damage. Microwave radiation is harmful to people who are under the influence of drugs.
To ensure that microwave radiation can’t harm you, you must not stand near the device. For this purpose, you must ensure that the oven is in its original spot or have a cover to protect it.
Few things to follow in domestic usage of microwave ovens
Oven manufacturers urge the users not to use an empty range. The microwave energy reflects in the magnetron when there’s no food in it and can destroy it.
Users of microwave ovens should read and follow the manufacturer’s instructions. As new ranges differ in design and efficiency.
Most modern ovens can withstand food packaged with metal. Manufacturers do not recommend putting material made of metal in the range. Particularly not near the interior walls. This causes electrical arcing and damage to the oven walls.
Also, food wrapped in aluminum foil won’t cook because it reflects microwaves. Food not covered in the metal wrap can receive more energy than expected. May result in causing uneven cooking.
Precautions that need to be followed
Radiation from the microwave will heat the body tissues the same way it heats foodstuffs. Exposure to high levels of microwaves may cause a painful burn.
The eyes, and the testicles, are especially susceptible to radiofrequency heating. Because they have little blood flow to remove excess heat.
The eye lens is especially susceptible to extreme heat. It can cause cataracts by exposure to high microwave levels. Only exposure to massive quantities of microwave radiation will cause these.
You might expect more energy from the power cable to convert into heat and losing less in different ways. You would expect a microwave to be much more potent than other forms of cooking.
In general, that’s right. Cooking in a microwave is cheaper and comfortable than cooking in conventional ovens. Because before you can cook, you don’t have to heat the stove itself.
But that’s not the story as a whole. A microwave oven isn’t the safest thing to use if you want to heat a tiny amount of food (or a cup of hot water).
You’re also powering an electric motor that spins a heavy glass turntable. When you microwave anything, besides putting energy into the food.
Although you don’t have to heat the food compartment to cook. After it’s been on for a while, a microwave oven gets pretty hot, so there are some heat losses.
Cook food – Regular oven Vs. Microwave oven
Differentiating conventional ovens with microwaves is easier. To transform electricity into microwaves. A magnetron is not always a hundred percent efficient: it will get hot itself.
And an electronic circuit, a timer, and a cooling fan operate as well. All these things, taken together, make a microwave less energy efficient than it should be.
If it is from a microwave or a regular oven, some nutrients break down under heat. The most evident example is vitamin C.
Since microwave cooking times are shorter. It does a better job maintaining vitamin C and other nutrients that break down when heated.
Cooking vegetables in water eliminates some nutritional value. Since the nutrients leach out into the cooking water. Boiled broccoli, for example, loses glucosinolate.
This compound contains sulfur that can give the vegetable its cancer-fighting properties. As well as the taste that many find distinctive and some find disgusting.
Is steaming vegetables any better in a microwave oven? For instance, more glucosinolate holds on to steamed broccoli. Than boiled or fried broccoli.
Maintenance Processes of Microwave ovens
It would be best if you did not run an empty microwave, as it will overheat the microwave and destroy it. There’s no harm a minute or two can do, but don’t gamble it any longer than that.
Luckily, microwave ovens are almost trouble-free. The owner can fix many of the issues themselves.
It will be essential to repair the interlocking switches, fan, thermal cutout. Also, the turntable motor, temperature sensor, light bulb, or the door.
Never try a microwave oven to operate the magnetron. It is dangerous. Make sure the power is on at the outlet. Test the electrical cord if the microwave is not going to operate at all. Check the fuse and, if it is defective, repair it.
To ensure that it closes, check the door as well. Test the fan and, if necessary, replace it. Always fit the door interlock switch, the thermal cutout, and the fan.
Inspect the plastic coupling underneath the tray if the carousel doesn’t move. Check the roller’s assembly to make sure the tray sits at the level of the turning mechanism.
Please take it to a service center that operates on microwave ovens. If you ever have issues with it, such as an exploded fuse. An awful mess of decayed burnt-on food or a thriving cockroach culture inside.
Seal it properly as long as there is no severe damage to the door. A 6-inch hole will count as severe damage, and the door fits square. There should be no leakage from there, as long as the waveguide is in place and undamaged.
Ensure the metal cover has all its fingers across the front. However, there should be some microwave leakage into the electronics bay.