Possibilities For Distortion of an Image On Displays

Are there any other conditions you want to impose while asking the forum to do your work for you?

Anonymous posters are lucky to get any response at all.

I believe that most engineers are high school level members, who have continued their education.

That's what you should do, continue your education.

Help denied!

GA

GA

That high??????

I was trying to be kind.

Then don't expect an answer at all.

GA for your thoughts!!!

Good picture too!!!

First, you've not explained why you believe the image is distorted. For all we know from your description, the thermal image may just be different from your expectations. You also provide us absolutely no description of the type of distortion your getting. Is the focus changing, a herringbone (moire) interference pattern appears, object location shifts, etc. There are just so very many types of optical distortions possible.

You must explain yourself better than a high school student to get a better answer than a high school lecture.

Radiated interference, conducted interference, earthing problems, mains phase problems, operator error...Thermal interference... an AC system is supposed to cool things down so one would expect it to effect a thermal image.

Allowing for the well known law of sod, it will be more than one of the above.

You give almost no useful information. You imply the AC system is responsible for the distortion but provide no information to back this up. What are you imaging? Move it away from the AC system or are you looking at the thermal image of the AC...

It should be simple enough to ascertain if the display itself is being distorted or the data going to the display is being distorted. Mind you'll need to be an engineer to work out how to do it.

Solving problems is easy... the hard part id finding out what the problem is.

Del

AC systems suppose to cool things down,.... but not so much for the AC unit itself.

Law of SOD,.... thanks,... I didn't realize there was a law for that, with the exception of Murphy's law.

Ah, to be sure I think Mr Sod was Murphy's nephew

The law states:-

a) If it can go wrong it will go wrong, unless going wrong creates a useful result.

b) If fault A is fixed it will immediately fail again due to the previously undetected fault B. Both faults must be fixed simultaneously else each will cause the other to fail again.

The corollary to this is that if both fault A and B are diagnosed at the same time and fixed there will be a fault C which... and so on.

Should all faults be diagnosed and fixed, the test equipment leads will go open circuit or the batteries will go flat/mains will drop out.

Any new hardware will seldom work first time. New software never will.

reading the manual will only help if you have the correct manual and even then it will probably refer to a different model.

Help lines work by keeping you holding long enough to think of your own solution.

The customer is always right unless it's you....

Del

I had (2) wrongs that made a right one time..... I felt pretty good about that.... and lucky

I have an air condition, an ac system close to a thermal image system. The image is getting distorted when it is displayed in a multi-function display system.
You answered the question yourself there!
Here is my solution - "MTFACA"

Eh?

Del

It's my own acronym and not very polite either!

Move

The

F***ing

Air

Conditioner

Away

LOL!!

And perfect!!!

Thanks

Close maybe?

Possibly "Make the effing Air Conditioning Away?" DUUHHH?

Google did not help me......can you?

Just apply Maxwell's silver hammer to the problem.

Does it look like his:

Or this:

Or this?

like the second image, the image is sometimes vibrating, it is not stable, and sometimes like a wave image. I moved an AC air-conditioning system away from the thermal imager, but it did not solve the problem, the image still unstable, it is like waving. My cables of dc and ac are separated a good distance from each other. my connection is good. I am not sure what else need to looked to make my image a stable.

Do you have a refrigerator magnet on the side of your display?

Nice one... LOL

Del

If your image looks like one that Lyn posted, then you have a severe magnetic disturbance somewhere near your imager.

• Is the A/C and thermal imager powered by the same AC power circuit (i.e Circuit breaker)?
• Have you tried turning the A/C off and imaging? What are the results?
• Is there another possibility of magnetic interference in the room or on your power circuit. A microwave oven?
• Shut down all other appliances and machinery and use the thermal imager. What are the results?

A/C powered a different power circuit from thermal imager, and each have it is own circuit breaker.

when turned A/C off, an image is stable and looks fine, no wavering, but when turn ON A/C, the image start vibrate and also start wavering.

there is only magnetic compass close to displays. there is VHF antenna on the roof close to A/C. There is radios close to displays. Do they have any influences to the video signal any of those equipment. No. because I tried to turn off all of those equipment, but the image still vibrate.

I think you found the problem. It's the A/C. Find a better place to have the A/C positioned.

Aim the air conditioner into the nearest skip. Problem solved.

Next!

Back in the days of CRT computer monitors, I had a cheap desk fan (plastic case, no shielding). It would make the image on the screen vibrate as the magnetic field from the motor windings was almost but not quite equal to the refresh rate of the CRT. (The electron beam in the CRT is magnetically deflected.)

If this is your problem, you need magnetic shielding and/or separation.

back in the early 90's, A large commercial furniture manufacture I used to work for,,,,, (no this happened after I left.) Designed and built a motorized work station where the desk top raised and lowered by an electric motor..... they never spec'd out the correct motor...... and it interfered with the monitor.

I will try magnetic shielding. what is separation, would you clear this.

What type of shielding are you going to try?

• Lead sheeting?
• Faraday caging?
• Shield grounding?

I'm not trying to be a jerk... I'm trying to help.

HERE is a WIKI website on shielding. If you are still having issues after trying some shielding attempts, contact some of the companies that are listed in the PRODUCT AND SUPPLIERS PAGE.

There were 50 hits on the search and one company that deals with nothing but EMI and RFI shielding

Mu metal is typically used for magnetic shielding.

http://www.magnetic-shield.com/faqs-all-about-shielding.html

I know nothing about your physical layout. If your problem is CRT distortion from stray magnetic fields from your AC (likely a motor), separating the two systems might be the simplist solution. Magnetic force drops off as the cube of distance.

Wasn't my problem,..... As I understood it, the motor was too close to the monitor, and built into the workstation. There were a number of units (in the thousands) already sold (GSA projects).

The only testing that was done was the workstation it self (Dose the table raise and lower), nothing was done in a working environment.

There really was not any motor specification the engineers put on it. I have a feeling that some of the engineers graduated from a local technical college, and the only research they did, was that the engineers went into the Engineering Department at this college which still had some drafting tables that were motorized..... they just looked at the motors the drafting tables had. And at the time, CAD was not implemented.

And probably copied the design of the table themselves

It's probably OK now if they have flat screens.

What happens when the air conditioner is switched off? No, don't bother. It is of no real interest.

I have an air condition, an ac system close to a thermal image system.

And YOU cannot see the PROBLEM????

This sounds like our "friend" from a previous Anonymous Posting who apparently still hasn't quite gotten his system, or his manners, to work right. There are many people here who know how to solve your problem, but who don't want to stoop to your level or take a demotion to your pay grade. Good luck to you and your client...

nb- maybe this should closed as a duplicate thread...

Thanks, I will check this.

Please make up your mind. In one sentence you say the AC is close to the TI, but then you say it is not close.

This could be the refrigerant circulating through the copper coil creating an electromagnetic field...move the imager further away...

both they are about one foot away from each other and someone install them to be that way. so moving them into different location, will not work. I have to find other solutions.

You might try grounding the copper tubing...

Try this:

You may not like this, but magnetic shielding is difficult and expensive compared to physical separation, it will be far more effort than physical separation and probably will not work anyhow (this is why you seldom find magnetic screening used).

Once upon a time, the television frame rate was locked to the electrical grid frequency. This was because picture waved about due to phase changes between TV HT supply ripple at grid frequency and frame waveform. I have also known the magnetic field due to the current in overhead fluorescent lighting tubes to distort the image on a computer CRT display intolerably.

Some electronic equipment, like digital voltmeters, samples at a multiple of mains cycle time because AC ripple on DC being measured can cause a seemingly erratic change of reading.

Some thermal imagers scan a spot sensor in a raster over the field of view - it seems possible that scan is being upset by an external field or interference conducted through the supply.

I suggest moving the display away from the AC unit even temporarily - just pulling the display out forwards onto a step-ladder or table may make a difference - magnetic fields fall steeply with distance - Hi-fi sound amplifiers put the power transformer as far as possible from the inputs, else they would never be "low hum" [and they do not use magnetic shielding, it is too expensive].

So long as "go" and "return" of a circuit are in the same cable, the magnetic field is minimal - it is possible the hot cable of the A/C unit has been separated from the neutral to go to an on/off switch in your panel, making a "turn" close to your display.

The idiot who put the display next to the A/C unit obviously did not test the system to be sure it worked, "shake his birdcage".

67model

STOP SMOKING POT! things should clear up in a day or two.

Is your display a Cathode Ray tube (CRT)? If yes, Move it to the floor and see if the issue clears. If it does great, You have magnetic interference I.E a placement issue.

If it does not it needs to be degaussed!

If the Display is LED then the issue is elsewhere!

my 2 cents

The OP already said that when they turn off the A/C then the display clears up.

Turn on the A/C and it distorts.

I think the answer was clear 2 days ago.

I just scanned through all eight of our AP replies. None of them say what kind of a display is being distorted. The only comment that even refers to what kind of distortion is happening refers to an image lyn posted that I see only as a broken, "file not found", icon. I guess my High School computer cannot read lyn's image.

Visit Carsten Nicolai's website here.

You missed the boat Einstein.

Your issue does not require an in-depth engineering solution nor a Quantum-Theory discussion.

In fact the reason simple issues such as you describe continue to exist is usually because a common sense approach has not been applied and/or the installer did not read the instructions manual thoroughly.

The issues may be something as simple as use of the wrong signal cable or loose connections, or poor power quality, or?

AC units generate a high level of magnetic waves especially during the compressor start cycle.

AC units also generate a high level of power disturbances during their start and stop cycles as well as contributing high levels of harmonics and other electrical noise to the power system.

The fix:

Install an isolated UPS for powering the imaging system to address the power noise issues.

Check the entire system for improperly installed components, loose fittings, poor quality cables/wiring, incorrect cable size or configuration, unsupported system components, and incompatibility issues.

If the above does not address the issue(s):

Measure the intensity of magnetics around the display or simply move the display far enough from the AC unit so that it is not affected. If you cannot move the display, purchase and install a shielded display. (Not cheap)

As for the many reasons video is affected by magnetic and electrical noise you need to study all facets the subjects in-depth, be sure you understand it well, then study the design of the particular equipment in question to narrow down the exact cause(s) of the issues. (Reverse engineering)

In a nutshell;

Magnetic fields tend to cause deflection of and movement of conduction band electrons which severely disrupts video alignment on/in the display.

Power noise tends to raise havoc with any non-hardened electronic circuitry which in turn negatively impacts the alignment of video displays and is often reflected on the video display as dots, distorted shapes, and/or random lines that are usually asymmetrical waveforms.

If you want to discuss this subject down to the atomic or sub-atomic level, I suggest you have conversation with a physics professor although I am quite sure finding one that has the knowledge of video displays in reference to atomic theory will be quite difficult.

If you were in my 6th grade English class, I would give you a failing grade in composition.