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kwoznia1
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Reading a "Lighting Chart"?

01/18/2011 9:28 AM

Good morning, can someone please try to explain to me how to read this? I am soooo lost at this point, any guidance would be greatly appreciated.
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PWSlack
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#1

Re: Reading a "Lighting Chart"?

01/18/2011 9:31 AM

What's it for?

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kwoznia1
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#2
In reply to #1

Re: Reading a "Lighting Chart"?

01/18/2011 9:34 AM

This one specifically I grapped off an LED WallPack produced by Dialight.
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KJK/USA
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#3

Re: Reading a "Lighting Chart"?

01/18/2011 9:39 AM

It appears to be a chart of the illumination pattern produced by a light fixture.

I believe the 90 degree mark is the wall that the fixture is mounted to. The heavy and light lines below the 90 degree mark are the illumination pattern and intensity (lumen's???).

If not lumen's then primary and secondary illumination patterns.

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kwoznia1
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#4
In reply to #3

Re: Reading a "Lighting Chart"?

01/18/2011 9:42 AM

Yes sir, I have concluded that much. Do you have any idea on how to read it? I understand that light is luminating forward but why are there 2 areas , one solid line, one dashed line. As well as what are the diameter numbers represent.

Next step is to contact supplier.

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NotUrOrdinaryJoe
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#5
In reply to #4

Re: Reading a "Lighting Chart"?

01/18/2011 9:56 AM

It looks like two LED's are being compared. The circles represent the relative amount of power radiated. So for an angle of say 60 degrees, one LED would be visible while the other is much less visible.

I can't tell you which one is the reference LED because I don't have the additional information with that graph.

So from this graph, you can pick out the wide angle LED's unless your purpose is to have one visible from a distance.

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kwoznia1
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#6
In reply to #5

Re: Reading a "Lighting Chart"?

01/18/2011 9:59 AM

Now it makes sense, thank you. :)
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redfred
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#7

Re: Reading a "Lighting Chart"?

01/18/2011 10:01 AM

This is a chart that shows the two dimensional pattern of the luminous intensity from 2 different LEDS. Possibly the same LED with and without a specific diffuser. The solid red line LED produces about 870 lumens directly on axis but at ±30° off axis this LED produces only 200 lumens. At any other angle above |35°| the illumination is effectively non-exist for the solid red LED pattern. The dotted red line LED produces only 850 lumens directly on axis but at ±30° off axis this LED still produces about 680 lumens of light. At about ±45° two other peak luminosities of about 850 lumens exist for the dotted red LED. At ±60° the dotted LED is still producing about 300 lumens. Above |70°| the illumination is effectively non-exist for the dotted red LED pattern.

This type of a chart is commonly found in showing the directionality and gain of an antenna design.

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Usbport
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#8

Re: Reading a "Lighting Chart"?

01/18/2011 10:02 AM

It's the lighting pattern in two orthogonal axes. In one axis the lighting is tightly concentrated, in the other it is spread fairly widely. So you have a beam that is narrow in one axis and wide in the other, like a fan of light.

It's produced by placing a cylinder (or oval) lens in front of the LED, rather than a 'normal' lens that would produce a round illumination pattern.

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JohnDG
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#9
In reply to #8

Re: Reading a "Lighting Chart"?

01/18/2011 10:20 AM

Usbport is spot on (pun intended ).

For a tube type LED array with a reflector, C0/C180 is perpendicular to the tube, and C90/C270 is parallel to the tube. Same measurements are used for fluorescents & linear filaments etc., see e.g. here.

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Nigh
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#10
In reply to #8

Re: Reading a "Lighting Chart"?

01/19/2011 7:15 AM

Quite right, the broken line shows what's known as a 'bat wing' distribution which gives reasonably even illumination on a flat surface.

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msamad
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#11

Re: Reading a "Lighting Chart"?

01/19/2011 7:06 PM

Here are some links that may help:

http://www.egsatx.com/english/produits/guide/G62-G63.pdf

http://www.uncg.edu/iar/elight/learn/design/lc_sub/photodis.html

- MS

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JohnDG (1); KJK/USA (1); kwoznia1 (3); msamad (1); Nigh (1); NotUrOrdinaryJoe (1); PWSlack (1); redfred (1); Usbport (1)

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