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Originally Posted by lemetier
Sure when I have a chance. It's a PITA to use that site on my phone.
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I edited my post; UNECE still literally says that its valid for leds exceeding 2000lm, in no. 48 art 6.2.9.
BTW Canada only follows part of UNECE. For example not No. 48 (or 45) but do No. 98 for example. Strange.
Quote:
Originally Posted by lemetier
That's why the units of measurement and photometric points
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Photometric points? whats that? Do you have a physical unit formula deriving to SI? I'm not good with trivial terms but do know my physics...
As far as regulations go regarding this cleaning system matter, all I see is stuff in lumen. (thus total light output)
Quote:
Originally Posted by lemetier
Hotspot was the wrong choice of adjectives so I edited to Mid Field (the 25m - 50m distance of Zones II and IV).
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Lumen in the mid field still doesnt make sense physically speaking. Lumen is the total output of a light (actually 1lm = 1 candela x 1 steradian). What you mean is either Candela (the amount of light in a certain angular trajectory, so intensity of a light, as in beam) or Lux (the amount of light on a certain area (per mē so to say).
2 lightsources with exactly the same amount of lumen output can give a totally different light intensity/illumination at a certain distance. It all depends on how the light is focussed. A light with very very low lumen can still create a very high intensity beam (think laser and such).
The amount of lumen used in the legislation has no direct relation to what light intensity is measured with that f90 headlight in the hotspot or midfield or whatever. (do you have a link to the report about those 3448.9lm? Then I can maybe see what mixup they did in their measurement/calculation or writing of the report)
But all legislation regarding washer cleaning systems on headlights is dependant on the amount of lumen, which makes sense as that determines the total amount of possible diffraction hindering oncoming traffic if a headlight is dirty. That effect of diffraction by a dirty headlight is also a little bit akin to how lumen output of a lightsource sometimes is measured (without using elaborate sensor arrays), by converting the output to a total diffuse radiation pattern, which shows that it's the right physical unit to use in this matter.