Induction cookers

Groupon has a Prima double plate induction cooker with 5piece pot set for R1486 - available for two more days - good deal?
 
Erm http://en.wikipedia.org/wiki/Non-ionizing_radiation

Non-ionizing radiation
Non-ionizing (or non-ionising) radiation refers to any type of electromagnetic radiation that does not carry enough energy per quantum to ionize atoms or molecules—that is, to completely remove an electron from an atom or molecule.[1] Instead of producing charged ions when passing through matter, the electromagnetic radiation has sufficient energy only for excitation, the movement of an electron to a higher energy state. The region at which radiation becomes considered as "ionizing" is not well defined, since different molecules and atoms ionize at different energies. The usual definitions have suggested that radiation with particle or photon energies less than 10 electronvolts (eV) be considered non-ionizing. Another suggested threshold is 33 electronvolts, which is the energy needed to ionize water molecules. The light from the Sun that reaches the earth is largely composed of non-ionizing radiation, since the ionizing far-ultraviolet rays have been filtered out by the gases in the atmosphere, particularly oxygen. The remaining ultraviolet radiation from the Sun is in the non-ionizing band, and causes molecular damage (for example, sunburn) by photochemical and free-radical-producing means that do not ionize.[2]

Different biological effects are observed for different types of non-ionizing radiation.[3][2] A difficulty is that there is no controversy that the upper frequencies of non-ionizing radiation near these energies (much of the spectrum of UV light and some visible light) is capable of non-thermal biological damage, similar to ionizing radiation. Health debate therefore centers on the non-thermal effects of radiation of much lower frequencies (microwave and radiowave radiation).

Health risks
Non-ionizing radiation can produce non-mutagenic effects such as inciting thermal energy in biological tissue that can lead to burns.

In terms of potential biological effects, the non-ionizing portion of the spectrum can be subdivided into:
  • The optical radiation portion, where electron excitation can occur (visible light, infrared light)
  • The portion where the wavelength is smaller than the body. Heating via induced currents can occur. In addition there are claims of other adverse biological effects. Such effects are not well understood and even largely denied. (MW and higher-frequency RF).
  • The portion where the wavelength is much larger than the body, and heating via induced currents seldom occurs (lower-frequency RF, power frequencies, static fields).
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Also See http://en.wikipedia.org/wiki/Electromagnetic_radiation

Electromagnetic radiation
Electromagnetic radiation (EM radiation or EMR) is a form of energy emitted and absorbed by charged particles, which exhibits wave-like behavior as it travels through space. EMR has both electric and magnetic field components, which stand in a fixed ratio of intensity to each other, and which oscillate in phase perpendicular to each other and perpendicular to the direction of energy and wave propagation. In a vacuum, electromagnetic radiation propagates at a characteristic speed, the speed of light.

Electromagnetic radiation is a particular form of the more general electromagnetic field (EM field), which is produced by moving charges. Electromagnetic radiation is associated with EM fields that are far enough away from the moving charges that produced them, that absorption of the EM radiation no longer affects the behavior of these moving charges. These two types or behaviors of EM field are sometimes referred to as the near and far field. In this language, EMR is merely another name for the far-field. Charges and currents directly produce the near-field. However, charges and currents produce EMR only indirectly—rather, in EMR, both the magnetic and electric fields are produced by changes in the other type of field, not directly by charges and currents. This close relationship causes the electric and magnetic fields in EMR to stand in a fixed ratio of strengths to each other, and to be found in phase, with maxima and nodes in each found at the same places in space.

EMR carries energy—sometimes called radiant energy—through space continuously away from the source (this is not true of the near-field part of the EM field). EMR also carries both momentum and angular momentum. These properties may all be imparted to matter with which it interacts. EMR is produced from other types of energy when created, and it is converted to other types of energy when it is destroyed. The photon is the quantum of the electromagnetic interaction, and is the basic "unit" or constituent of all forms of EMR. The quantum nature of light becomes more apparent at high frequencies (or high photon energy). Such photons behave more like particles than lower-frequency photons do.

In classical physics, EMR is considered to be produced when charged particles are accelerated by forces acting on them. Electrons are responsible for emission of most EMR because they have low mass, and therefore are easily accelerated by a variety of mechanisms. Rapidly moving electrons are most sharply accelerated when they encounter a region of force, so they are responsible for producing much of the highest frequency electromagnetic radiation observed in nature. Quantum processes can also produce EMR, such as when atomic nuclei undergo gamma decay, and processes such as neutral pion decay.

EMR is classified according to the frequency of its wave. The electromagnetic spectrum, in order of increasing frequency and decreasing wavelength, consists of radio waves, microwaves, infrared radiation, visible light, ultraviolet radiation, X-rays and gamma rays. The eyes of various organisms sense a small and somewhat variable but relatively small range of frequencies of EMR called the visible spectrum or light.

The effects of EMR upon biological systems (and also to many other chemical systems, under standard conditions) depends both upon the radiation's power and frequency. For lower frequencies of EMR up to those of visible light (i.e., radio, microwave, infrared), the damage done to cells and also to many ordinary materials under such conditions is determined mainly by heating effects, and thus by the radiation power. By contrast, for higher frequency radiations at ultraviolet frequencies and above (i.e., X-rays and gamma rays) the damage to chemical materials and living cells by EMR is far larger than that done by simple heating, due to the ability of single photons in such high frequency EMR to damage individual molecules chemically.

Health effects

The effects of electromagnetic radiation upon living cells, including those in humans, depends upon the power and the frequency of the radiation. For low-frequency radiation (radio waves to visible light) the best-understood effects are those due to radiation power alone, acting through the effect of simple heating when the radiation is absorbed by the cell. For these thermal effects, the frequency of the radiation is important only as it affects radiation penetration into the organism (for example microwaves penetrate better than infrared). Initially, it was believed that low frequency fields that were too weak to cause significant heating could not possibly have any biological effect.[6]

Despite this opinion among researchers, evidence has accumulated that supports the existence of complex biological effects of weaker non-thermal electromagnetic fields, (including weak ELF magnetic fields, although the latter does not strictly qualify as EM radiation[6][7][8]), and modulated RF and microwave fields.[9][10][11] Fundamental mechanisms of the interaction between biological material and electromagnetic fields at non-thermal levels are not fully understood.[6] Bioelectromagnetics is the study of these interactions and effects.

The World Health Organization has classified radiofrequency electromagnetic radiation as a possible group 2b carcinogen.[12][13] This group contains possible carcinogens with weaker evidence, at the same level as coffee and automobile exhaust. For example, there have been a number of epidemiological studies of looking for a relationship between cell phone use and brain cancer development, which have been largely inconclusive, save to demonstrate that the effect, if it exists, cannot be a large one. See the main article referenced above.

At higher frequencies (visible and beyond), the effects of individual photons of the radiation begin to become important, as these now have enough energy individually directly or indirectly to damage biological molecules.[14] All frequences of UV radiation have been classed as Group 1 carcinogens by the World Health Organization. Ultraviolet radiation from sun exposure is the primary cause of skin cancer.[15][16]

Thus, at UV frequencies and higher (and probably somewhat also in the visible range),[17] electromagnetic radiation does far more damage to biological systems than simple heating predicts. This is most obvious in the "far" (or "extreme") ultraviolet, and also X-ray and gamma radiation, are referred to as ionizing radiation due to the ability of photons of this radiation to produce ions and free radicals in materials (including living tissue). Since such radiation can produce severe damage to life at powers that produce very little heating, it is considered far more dangerous (in terms of damage-produced per unit of energy, or power) than the rest of the electromagnetic spectrum.
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Quintrix said:
Groupon has a Prima double plate induction cooker with 5piece pot set for R1486 - available for two more days - good deal?
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Not too bad actually - if you don't need the pot set you can probably buy the cooker cheaper - I've seen different makes with prices ranging from R500 to R1500 for the tabletop hotplates - the Prima one costs about R1300 anyway, as far as I can tell, without the pot set.
 
Archer said:
But why would they need to if there is no inherent danger? :confused: You make no sense :p
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Because scaremongerers have released reports about there being potential danger in the past, which is slowly being debunked. I imagine the major issue for manufacturers is potential long-term exposure liability - just look at the cellular conspiracy nutters like Karl Muller - people punt bullschit all of the time and others listen.

I imagine the other major stepping-stone to overcome for manufacturers is that they are more than likely not the patent-holders...
 
We bought a one plate Prima one from Hirsches for about R500. Only have 2 pots that work on it though
 
RustyPrincess said:
We bought a one plate Prima one from Hirsches for about R500. Only have 2 pots that work on it though
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Are you satisfied with the quality of the Prima one?

AlphaJohn said:
Just got reminded that I forgot to post the info on our Cooker.

The guy that imports them sells it via Bid or Buy See: http://www.bidorbuy.co.za/item/78893470/Induction_Hob_plate.html

Its a Bradkir unit, and so far I have no complains on the unit or service we received.
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Thanks for the info :)
 
Archer said:
:confused:
Could you explain this... What hazard is there from 25kHz non ionizing EM radiation?
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I'm very wary of EM radiation - so I refuse to have a microwave in my home - but simple induction seems to me to be safe (unless you hold your hand in the pot/pan and get burnt, of course - it's not magic). There is no 'radiation' involved, as far as I can see, only the normal magnetic field that is created around any changing electric field, i.e where either the conductor is moving or the electric current is increasing/decreasing - which is what happens in this case, since it's alternating current.
I may be wrong about this, but I have just bought an induction plate for my own use.
 
Carola said:
There is no 'radiation' involved, as far as I can see, only the normal magnetic field that is created around any changing electric field, i.e where either the conductor is moving or the electric current is increasing/decreasing
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You just described electromagnetic radiation perfectly.
 
Bumping this thread... What's the 2014 opinion on induction stoves?
 
I use mine daily - very useful for jamming energy into something fast - somewhat like a microwave except stove top format.

Also...takes a bit of time to get used to it...doesn't behave the same as a standard stove top.

AlphaJohn said:
PS: if you where a metal(Magnetic) watch/jewelry, kind of remove it before you cook supper.
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Not necessary. Its got a couple of millimeters range. Never took off my watch & used a bunch of metal cooking implements near it. "Don't be an idiot" seems to cover it safety-wise.

On balance I'd rank an electronic pressure cooker higher on the "must have" list though.:love:
 
HavocXphere said:
I use mine daily - very useful for jamming energy into something fast - somewhat like a microwave except stove top format.

Also...takes a bit of time to get used to it...doesn't behave the same as a standard stove top.


Not necessary. Its got a couple of millimeters range. Never took off my watch & used a bunch of metal cooking implements near it. "Don't be an idiot" seems to cover it safety-wise.

On balance I'd rank an electronic pressure cooker higher on the "must have" list though.:love:
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Be more specific... What took getting used to?
 
Also have one.... It makes gas looks like a turtle
 
eehellfire said:
Be more specific... What took getting used to?
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The heat is so fast it's easy to burn things if you're not careful. Getting a hang of how the wattage relates to the heat and so forth. Other than that it's pretty straight forward. There are cheap ones for R500 odd if you don't want to commit to a larger one.
 
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