Computer Monitor Flickering

[karl riley]

Re: Computer Monitor Flickering

hbiss, you speak as a knowledgable expert on the health effects research. Please cite the research you are familiar with and how you come to your conclusions.

I think you failed to read my post. I said that if we correct the NEC violations, the fields disappear. As an electrician are you saying NEC violations are something to ignore because they produce high magnetic fields? I don't think so.

This is an emotional issue, as you have shown.

Fix the violations, that's all. A gaussmeter is a very useful tool in locating sources of net current, which is usually due to neutrals connected in violation of NEC.

Karl

 

[karl riley]

Re: Computer Monitor Flickering

Second note: how long did it take from when smoking showed up as connected to disease to the passing of regulations about smoking? I just returned from Europe. They are trying to pass no-smoking laws there. They are having fierce resistance. And in Ireland, too.

It takes time and the overcoming of ignorance and attitude (and vested interests). Smoking threatened cigarette companies and tobacco growers. EMFs from electrical sources has a huge industrial and military threat potential. It will take time.But the research is worldwide and cannot be stopped.

Karl

 

[hbiss]

Re: Computer Monitor Flickering

...hbiss, you speak as a knowledgable expert on the health effects research.
No, no more than anybody else. I threw away my electric blanket years ago but that's just me. I also wouldn't live in a house that is in close proximity to power lines. If somebody asked me, yeah, I would tell them that I personally wouldn't use an electric blanket but I wouldn't, in the course of my work, tell my customers not to use them or that transformer in the next room could make them sick. It's not professional, it's not my job, it's not my business.

You are right, this can be an emotional issue. Our customers (hopefully) consider us authorities and if we give them our personal opinions no matter how right we think we are, without disclosing that it is just opinion, then we are encouraging the paranoia.

If you want to do this, set up a company called "Joe's EMF Detection and Remediation" or something like that. Then people will know where you are coming from. To do it under the guise of electrical contracting, unless it's strictly by the NEC, gives undue legitimacy to something that at this point there is no official line on and needs more research.

 

[karl riley]

Re: Computer Monitor Flickering

hbiss, my company is called ELF Magnetic Surveys. I am an EMF consultant. I work with electricians, who make any corrections to the violations I may find.

Even so, I do not tell clients that EMFs are a health threat. I agree with you on the ethics about that. If they ask me where to find info on the matter, I can cite various references.

They call me. Most often these days it is because of power quality problems (computer monitor flickering, electron microscopes malfuntioning, etc). Why do they call an EMF consultant? Because the local electricians and electrical engineers can't figure out the source of the problem. So I go and find it and their electrician makes the correction.

I wrote my book, Tracing EMFs in Building Wiring and Grounding, to help electricians learn how to do what I do. And many have, and are thankful to have the info on the tracing techniques.

As for paranoia, that's a mental health problem.

Karl

 

[hbiss]

Re: Computer Monitor Flickering

Karl, my apologies. I have no way of knowing what you do and assumed you were a contractor like the many of us here.

 

[bwyllie]

Re: Computer Monitor Flickering

visited the site today and from what I was told( I did not see the monitor actually do this) the text ont he monitor would change colors and the screen would become distorted with "fuzzy lines". The measured field at the monitor was 2-3mg. This monitor was a good distance fromt he adjacent server room. A monitor on the other side of the workstation was located adjacent to the wall and reported no problems. I recommended the client to check the following:
All neutral and ground connections throughtout the workstation, branch circuit and at the panelboard.
Video card within the CPU
Bypass the UPS and see if it has any affect
Flat screen monitor
Refresh rates and settings of the monitor

Can anyone think of anything else to recommend or what may be causing this?

 

[hbiss]

Re: Computer Monitor Flickering

The first thing I would do is change the monitor then the PC. Sure sounds like a video problem. Like I said before, if it is a magnetic field problem moving the monitor will change the symptoms. I would procede in this order before trying more drastic measures.

Keep in mind also that if you didn't see the problem for yourself firsthand what they described might not be (and probably isn't) accurate. 90% of the time my customers relate a problem to me that when I actually see it is nothing like what they were talking about. Moral is you can't diagnose long distance.

 

[catchtwentytwo]

Re: Computer Monitor Flickering

Originally posted by bwyllie:
visited the site today and from what I was told( I did not see the monitor actually do this) the text ont he monitor would change colors and the screen would become distorted with "fuzzy lines". The measured field at the monitor was 2-3mg. This monitor was a good distance fromt he adjacent server room. A monitor on the other side of the workstation was located adjacent to the wall and reported no problems. I recommended the client to check the following:
All neutral and ground connections throughtout the workstation, branch circuit and at the panelboard.
Video card within the CPU
Bypass the UPS and see if it has any affect
Flat screen monitor
Refresh rates and settings of the monitor

Can anyone think of anything else to recommend or what may be causing this?

You might want to try an isolation transformer. Experiment with various hook-ups (UPS input, UPS output, monitor only, etc.). Also, see if changing the orientation of monitor causes any changes.

 

[karl riley]

Re: Computer Monitor Flickering

I've never seen computer monitor problems from magnetic fields at 2-3 mG. Usually the minimum is 5 mG and the usual is around 12 mG.

You could try moving the monitor, but I would suspect it is a problem with the monitor circuits.

Karl