Frequency of EM Waves from Monitor for Black/White & Color Images

In summary, the power consumption of an old monitor changes when the screen is white or black. However, the frequency of the weak electromagnetic waves emitted from the monitor does not change, but the output may be stronger or weaker. There is no evidence that older monitors cause harm from electromagnetic radiation. The only known danger is from x-rays produced by CRT monitors, which are absorbed by the glass. There is no accepted medical condition of electromagnetic hypersensitivity and those experiencing symptoms should seek medical advice.
  • #1
EleSuki
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TL;DR Summary
Are older monitors more likely to leak electromagnetic radiation? If so, I hypothesized that people with electromagnetic hypersensitivity might have symptoms caused by older monitors.
I am using an old monitor (MITSUBISHI RDT27IWLM). The power consumption changes when the screen is white or black, but does the frequency of the weak electromagnetic waves emitted from the monitor change? Or is the frequency the same, only the output is stronger/weaker?
 
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  • #2
EleSuki said:
The power consumption changes when the screen is white or black, but does the frequency of the weak electromagnetic waves emitted from the monitor change? Or is the frequency the same, only the output is stronger/weaker?
A black or white screen does not have detailed information to display, so the spectrum is lower in RF radiation energy, and less pixel logic transitions results in less power consumption.

Worry about hypothetical radiation from a flat screen monitor, will injure you more than the weak RF emissions from your monitor.

Smoking, driving cars, using mobile phones, or using CRT screens that emit x-rays, are very much more dangerous, and will hide any effects from a flat screen.
 
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  • #3
EleSuki said:
TL;DR Summary: Are older monitors more likely to leak electromagnetic radiation? If so, I hypothesized that people with electromagnetic hypersensitivity might have symptoms caused by older monitors.

The power consumption changes when the screen is white or black,
The reason for this is not particularly clear for an "old" monitor like yours. I googled the model but couldn't find the technology; it may be newer than you think, in terms of its system. I did find that the power supplied is 57W(?) which is very very low when you think that most of this will emerge as light, leaving very little to be 'radiated' as em/ radio frequency waves.

In truly old sets, the majority of the power is supplied to the backlight, behind the LDC picture elements and that is illuminated all the time. The lcd elements block. More modern sets use LEDs as backlighting for the LCDs and a brighter screen gives more power to those LEDs. So I wonder by just how much the power into your monitor changes; a lot or just a few percent?? Did you measure it? The rest of the circuitry (digital) consumes very little power.

If you want to talk about dangerous or harmless radiation from TV sets then the X Rays produced where high velocity electrons hit the front of the screen of a colour CRT are enough of a potential hazard that the glass front is made thick enough to absorb the majority. Also, the power of the magnetic fields which are used to deflect the electron beams is sufficient to cause interference at around 16kHz. But that's all ancient history.

The worst effect of watching TV monitors is the way the light can affect your diurnal rhythms. Modern laptops change the colour temperature of the display in later hours in an attempt to reduce the damage. Plus, as I tell my grandkids, watching too much TV gives you square eyeballs.
 
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  • #4
EleSuki said:
If so, I hypothesized that people with electromagnetic hypersensitivity might have symptoms caused by older monitors.
There is no such disease/disorder accepted by the mainstream medical community. While the symptoms are accepted as being real, there is little evidence linking them to electromagnetic radiation or fields.

Per ARPANSA (Australian Radiation Protection and Nuclear Safety Agency):
On the basis of current scientific information, there is no established evidence that EHS is caused by EMF at levels below exposure guidelines. ARPANSA acknowledges that the health symptoms experienced by the affected individuals are real and can be a disabling problem, and advise those affected to seek medical advice from a qualified medical specialist.

As the posts above say, there is no known danger from computer monitors or TV's except in the specific case of x-rays produced by CRT's, which are absorbed by the glass before they can get out and harm anyone.

Since this discussion is based on the premise of a medical condition existing that isn't known to actually exist I am locking this thread.
 
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FAQ: Frequency of EM Waves from Monitor for Black/White & Color Images

What is the typical frequency range of electromagnetic waves emitted by a monitor displaying black and white images?

The typical frequency range of electromagnetic waves emitted by a monitor displaying black and white images is primarily in the visible light spectrum, which is approximately 430-770 THz. The specific frequencies depend on the phosphors used in the monitor and the refresh rate of the display.

How does the frequency of EM waves differ when a monitor displays color images compared to black and white images?

When a monitor displays color images, the frequency of EM waves includes a broader range of visible light frequencies corresponding to different colors (approximately 430-770 THz). Each color pixel is composed of red, green, and blue subpixels, each emitting light at different frequencies. This results in a combination of frequencies rather than a single frequency range as seen in black and white images.

Do monitors emit any non-visible electromagnetic waves, and if so, what are they?

Yes, monitors emit non-visible electromagnetic waves in addition to visible light. These include infrared (IR) radiation, which is typically in the range of 300 GHz to 430 THz, and very low levels of ultraviolet (UV) radiation. Additionally, monitors can emit radio frequency (RF) interference, especially in the range of a few kHz to several MHz, due to the electronic components and circuits within the device.

Is there a difference in the EM wave emission between CRT and LCD monitors for black and white and color images?

Yes, there is a difference in the EM wave emission between CRT (Cathode Ray Tube) and LCD (Liquid Crystal Display) monitors. CRT monitors emit more electromagnetic radiation, including X-rays, due to the electron beam striking the phosphor screen. LCD monitors, on the other hand, use backlighting (usually LED) and liquid crystals to produce images, resulting in lower EM emissions. The primary emissions from LCDs are in the visible spectrum and minimal IR radiation.

Can the frequency of EM waves from a monitor affect human health?

The visible light emitted by monitors is generally not harmful to human health under normal usage conditions. However, extended exposure to blue light, which is at the higher frequency end of the visible spectrum, can cause eye strain and disrupt sleep patterns. Non-visible EM waves, such as UV and IR radiation, are typically emitted at very low levels and are not considered harmful. It is always advisable to take regular breaks and use screen filters to minimize potential negative effects.

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