Working Under Flourescent Lighting.
Richard Williams posted on February 13, 2010 | 7492 views

Office Engineers & Other Workers

By Corporal Willy on Feb., 12th 2010

       I know the title might seem strange that I picked for this blog article, but I had to capture  the attention of anyone and everyone who works in an office setting that is suffering from bad eyesight like me or eyestrain that makes you want to get out of the office and away from the drafting boards and computer screens.  I have a pretty good idea here for a solution that will help you and your eyes.  Not a complete cure but a definite help and over many years can make a big difference to you.

      Remember, I am not an engineer or designer but what I really am is an old retired electrician even though I have never been busier in my whole life.  Getting back to the subject here let me tell and show you a very simple trick.  Since the time of the fluorescent bulb arriving upon the office scene in buildings and also with mobile job site offices, little or no attention has been paid to fluorescent light polarization.  Wow, this is like getting back into my five years of apprenticeship all over again.  However, I wanted to bring out to you some basic facts about this type of lighting as a subject here.   

     First of all we will not be seeing a quick change anytime soon to something more exotic in the lighting industry.   Also please don’t think that LED lights are going to make a great substitute.  No one is going to argue that they demand less energy than the old fluorescent bulbs, including the more efficient tubes out there.  However, there is a problem with screwing up the Power Factor of the supply system with LED lighting, that no manufactures or advocates seems to want to talk about.   But it does scare the living daylight (pun included) out of the electrical power plant industry.  Unless there is some sort of individual Power Factor Correction embedded into every LED lighting fixture, it can wreck havoc to the power companies trying to produce the power needed.  I won’t try to explain it technically because it has been too many years that have gone by now since I dealt with formulas for Apparent Power and True Power and PF correction.  We have enough electrical engineers out there as members that are eminently more qualified to touch upon this subject than me.  However, wasted power is something that we cannot afford to have in our newer, greener, LEED certified buildings. 

      Anyway, for the rest of us not being in new buildings working in areas where lighting is produced by the old workhorse industry standard namely the fluorescent bulb there is something you can do to help with eyestrain.  Look at that drawing board, desktop, table, or any area that is cluttered with your work or that of the team.  Are you using pens, pencils, tri-rulers, gadgets or something else where you have to try to look around shadows?  Yup, good lighting produces shadows from anything between your eyes and that which you are trying to see.  A bottle, whatever you are holding in your hand even your own hands and fingers.  Shadows at times can stop you from seeing those small details.  Okay, we are cutting to the chase now with some practical real photos taken with my camera and my fluorescent lights.  You will need a pencil and a clean piece of paper or note pad to prove this to your office manager because you will want to change the furniture around for yourself and maybe many others.  Here is what you do.  Pictures below describe it pretty good.

    While I was already in the computer room I decided to try it out on a circline or round fluorescent tube just to see what would happen.  However, even though it showed some of what I wanted you to see, it wasn’t the normal office type of lamp that most people work under today.

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I re-aligned the new note pad so the long edge would be parallel to the table and the lines on the pad would be perpendicular to that edge of the table where the small light was suspended over the pad.  Notice how harsh or distinct the shadow line is and I am holding it about 1/2 inch or approximately 9mm above the paper surface.

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When I re-orientated the pencil at a 90 degree angle from that first position and held it approximately the same distance off of the paper’s surface you can see the difference.  This is still not quite what I wanted to show you but now I am moving out into the garage area.

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Now please realize that I am in an area that would be similar to a commercial office with ceiling height at 10 feet and an average drafting table working surface at about this right height from the floor.

     The test parameters were done in my garage with lights that were T12-CoolWhite-34wattEnergyMiser.  A little known fact about fluorescent light bulbs is that they are gauged or sized in 1/8 of an inch.  So a T12 lamp is 1.5 inches in diameter a T8 would be 1 inch and these were 4 foot long and there were two of them in parallel.  This first picture shows the setup for the test.  There is a plastic lens diffuser covering the light that is supposed to spread the light more evenly.  Let’s see if it does.

    There is also something else I would like to say about these well known lights called florescents.  There is both mercury and argon gas inside the tubes.  The argon gas really only helps to get the arch going from the one end of the tube to the other end of the tube with a high voltage push.  The mercury gas is the main carrier for the arch once it gets going.  Fluorescent lighting produces ultraviolet rays and it can be particularly severe at the ends of the tubes.  They have an inside coating of Phosphorus Powder that converts the ultraviolet rays into  a different frequency light source that we see as a normal office type of lighting.  Even that comes in different flavors, like cool white, warm white, deluxe warm white and most likely some others that I have forgotten.  Keep in mind that the powders inside the tube are especially harmful to the eyes if one should break and that is not even considering the glass and toxic gases.

    If new bulbs were put in and you notice a swirling effect happening that can easily be stopped by taking the bulb out and turning it end over end to help distribute the inside gases better then put it back in the fixture.  In places where they could break easily from vibrations or things moving around they do have plastic guards that will sleeve over them.  Now you know everything that I know about this type of lighting but there are wiring them up which can be a challenge if you cannot shut down the lighting in a plant that is in heavy production.  Open line voltages of 750 volts to ground are produced inside the fixtures so do not work on them hot and the best way to handle that is to let someone else do it like an electrician.  We need you as an engineer.

Now I am going for a little more sophistication in my testing.  I’m trying to be an imitation of a real engineer here.  I have rubber banned a new pencil to a ruler at the 3 inch mark or 7.5 cm.  You will notice that I am holding the pencil at right angles to the two parallel fluorescent lights at this non changing 3 inch height.  I would have more of a shadow if it were held even closer but I tried to duplicate what I thought would be a hand holding a pencil at a normal distance.  The bulb reflections on the hood of my wife’s vehicle are a great identifier to what orientation I’m talking about.  The shadows in this next picture down below are bad and it would be a lot easier to work with if you were working in a perpendicular angle to the fluorescent light source, like in the picture below that one.  You definitely do not want to work when you are facing and looking in line with the lights.  I think you engineers call that a co-linear relationship.  I like things said easy so I can remember them like “Righty Tighty and Lefty Loosey.”  Works for me and I hope this works for you. 

It is not easy to work under them when you have a bad orientation condition.  Now suppose I was able to take my work area and turn it 90 degrees clockwise or counter clockwise, it doesn’t really matter unless there is a pretty gal or handsome young guy you would like to rest your eyes on every now and then.  But look at the difference in the shadowing here between these two orientations.   The bottom picture is almost a no shadow condition (second one down).  You have to realize that I am using a flash camera as I am holding the pencil so disregard the obvious shadow in the backside of the pictures when I took them.

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This could simulate a typical office florescent light and maybe it is in a field office, but more than likely yours are flush with the finished ceiling and it has four tubes placed parallel in the same fixture.  Next we will take off the diffuser to show this again and perhaps make it even clearer to everyone while I get up on the ladder to take the pictures rather than down on the floor.  I’m small so I’m not able to easily get above the hood of my wife’s Ford Explorer.

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The picture below here is showing you what the work surface might look like and at a reasonable height above the floor.  Illumination standards are set and used to get a certain amount of foot candle power to the average working surface in various building types.  Check with the National Electrical Codes for the USA.  I know there are other similar standards around the world.

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Now let us see how that is when the pencil point is placed on or near the surface of the paper.  I’m zoomed in close here to try and show more detail.  Once again you can see the flash shadow more than the very light shadow that is being made by the light when held at a perpendicular angle to the tubes.  That is not a dirt smear that is what is left of the very light shadow that was there as I took the picture.  With the picture that comes next after the one below here you can see a very distinct shadowing of the pencil  when you are in line with the tubes.  Yup it is the same carmera.

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Now when you feel like trying this yourself all you need is a pencil or pen and a piece of paper.  This is also for flourescent lighting not incandescent lights.  Place the paper down flat and just hold the pencil on the ends and rotate it 90 degrees while holding it a finger width or so above the paper.  You won’t be taking pictures like I did so you can keep both hands on this testing instrument.  After you play with it for a minute or two, call over the boss and tell him or she that they are ruining your eyes because of the lighting layout in relationship to your work desk.  Don’t threaten to quit the job because of it.  I don’t even think OSHA knows this or they might recommend aspirins.  If you don’t have any problem with the orientation and don’t suffer from harsh shadows show them this simple test trick and get a raise.  This is not the time to get fired so play it cool.  Oh yeah, turning the table or desk is preferable to turning the lights.  When making a delivery to a job site with a big truck once, I did not think the truck would make it under a pretty low train bridge according to the posted sign and the truck height.  I called and told the boss this and he told me to let the air out of the tires.  I had some traffic behind me so I took it slow driving under it.  I didn’t have a air hand pump so I took the chance.

I’m happy that you stayed with it and read this report.  I was glad to get it off my chest.  It has been a burden on my mind for a long time and I wanted to tell you about it for awhile now.  Since the desert got so wet from rain lately I haven’t been working on Solar One but will resume again soon, if the storms don’t start in again.  Hope this helped everyone around the world if they have this situation.  Bye for now. 

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