Reason(s) of Eye Strain
Hello,
Do you think the following can be related to what you mention above?
I have a "working" set up at my job, where I can work with barely any issues. I have tested many monitors at home with no success, dizziness etc.
This week I took my monitor at work to my home, using the exact same laptop and Usb C cable to connect to the monitor… but I feel dizziness at home!!! how is that possible?
The only differences of my home set up:
- I use a different AC power cable to plug the monitor (I charge the laptop thought USB C)
- The table I use is glass and has a metal frame. At work is a wooden table with metal legs.
- I work close to the Router
Does anyone has a possible explanation?
Thanks,
Hi!
Since your devices work well in one place and poorly in another, this narrows the search to AC problems.
First: what kind of electrical system do you use at work? Is there grounding? What kind of system do you use at home? I mean TN, TT, IT systems.
Second: your laptop most likely does not have a grounding contact in the power supply, so it is grounded to the monitor, and if there is grounding at work, but not at home - this may explain.
Third: both the desk at work and the desk at home have a metal base. The desk at work may be far from the walls from which AC interference comes, and on the contrary, the desk at home may be close to the wall, behind which there is wiring.
I will explain why this is important:
The metal absorbs interference from the walls and then this radiation goes to the devices located on the table. Even if your devices are grounded, interference will still penetrate from the metal base into your devices. To fix this you need to ground your table: connect the metal leg of the table to the ground contact in the socet.
fourth: AC has harmonic distortion. Different networks have different harmonics at different frequencies, and no one knows yet which frequencies affect our heads. (presumably the strongest influence is the low frequencies 100-2000hz)
Perhaps the electricity at your work is cleaner than at home.
Thanks for your reply.
I will try to find out about the grounding systems in both places and see if it is different.
My desk at home has wheels so I sometimes work in different locations in the room, far from the wall and I get dizziness too.
Would it help to have a grounding cable attached to the legs of the table?
It is necessary to distinguish between the interference (emi field) caused by AC and the frequencies that are in the emi field. External emi can be measured with a device such as wt3121 (as shown in the photos at the beginning of this thread).
frequencies can be measured with an oscilloscope.
What's the problem?
Even when your monitor will not emit any field (0mV), (at least that wt3121 sees), bad frequencies will still be emitted from your pc, monitor, walls of your house.
The AC emit itself will always be present, that's physics. Only harmonics within this field have an effect.
I don't know what frequencies exactly are projected when increasing the voltage of system components (cpu/ram/gpu)
- Edited
Slender
Hope you understand that the "chinese emi tester" you're using is a glorified AM radios (at best) which isn't calibrated for measuring the necessary range you're trying to target, spouting random values.
Take a look at this review for more information
You're supposed to use a proper spectrum analyzer from reputable brands such as LeCroy, Keysight, Rohde & Schwarz, Tektronix for this type of troubleshooting, especially when approaching the 2.4–5GHz range.
yes i understand that. And yet it showed a problem. In my case the interference was breaking through to the pc from the metal table. And this is despite the fact that my pc was grounded. I still got 25-35 mV from the monitor screen and the pc. It was very interesting to discover this: I touched the pc case with my hand and the table leg with my foot and saw how the values dropped to 0.
CAP I do not have an explanation, but I share a similar story. All the screens that started bothering me were used at home, specifically in one area where my desk is. At work I had far fewer issues, but when I took screens from work to try at home, then they started bothering me in both places. I do suspect some kind of electrical, grounding, or emission problem in that area at my home that made me sensitive to those screens.
- Edited
I have done some more tester readings and now the screens shows some mV, depending on where I am located in the room but in the place where I work the monitor shows low activity, like <10 mV. If I move the computer table and I sit on the sofa the tester goes to >100 on the scren.
When I connect the monitor to the table PC, on the same table, the monitor show >40
The laptop show as well some some value both mV and uT.