Just how much data do I have to provide for you to listen. Maybe a Physics Professor from the University of Arkansas can explain to you:
You state: "There is no way you can convert lux to PAR/PPFD... you are talking two different things! You need to stop posting bad info. Also, you can not use a meter like that to get a lumen or PAR per watt figure!! It just doesnt work like that. There are reflectors in involved with what you did, so the intensity will vary with position. Lumens per watt calculations need to be done without a reflector, and are done by calculating the total incidental light from every angle around a light source, not by taking any spot readings. It can be determined by a point reading sometimes, if you know what your total area is and how it varies over that area, but you need integral calc to determine this ratio then.
You need a physics course on optics and the EM spectrum. Seriously... your info is just not right. You arent helping anyone.
Im shocked that Bean hasn't jumped on you already."
Here it is...
Date: Mon Jul 31 16:38:51 2000
Posted By: Jeff Robertson, Faculty, Physical Sciences, Arkansas Tech University
Area of science: Physics
ID: 964457090.Ph
________________________________________
Message:
Light measurements can be complicated but illuminating...
Photometric units, illuminance:
Footcandle = one lumen per square foot. The 16th General
Conference on Weights an Measures (CGPM), Oct. 1979, decided that the candela is the luminous intensity of a source emitting monochromatic radiation of frequency 540 x 1012 Hz and radiant intensity 1/683 watt per steradian. This corresponds to 683 lumens per watt of radiation at approximately 555 nm wavelength, which is near the maximum of the standard photopic spectral luminous efficiency curve.
Lux = one lumen per square meter.
Quantum units, photon flux density:
Microeinstein per second and square meter (µE m-2 s-1). The
einstein has been used to represent the quantity of
radiant energy in Avogadro's number of photons and also
Avogadro's number of photons. The second definition has the
einstein equal a mole of photons, While commonly used as a
unit for photosynthetically active radiation (PAR),
the einstein is not an SI unit.
Therefore: microEinsteins per m2 per second is identical to
micromoles per m2 per second.
(1000 µE m-2 s-1 = 1000 µmol m-2 s-1)
Micromole per second and square meter (µmol m-2 s-1). This term is
based on the number of photons in a certain waveband incident per
unit time (s) on a unit area (m2) divided by the Avogadro
constant (6.022 x 10e23 mol-1). It is used commonly to
describe PAR in the 400-700 nm waveband.
The approximate conversion factors given below will help to
convert absolute energy units or irradiance units (PAR)
as recommended by the plant scientist into illuminance
or photometric values (lux).
Radiometric PAR - Photometric
Source* W m-2 µE m-2 s-1 fc lux
HP Sodium 1 5 33.5 360
(400 w) 1 6.7 72.3
1 10.8
Metal Halide 1 4.6 29.6 319
(400 w) 1 6.5 69.5
1 10.8
Mercury 1 4.7 30.8 332
(400 w) 1 6.5 70.0
1 10.8
CW Fluorescent 1 4.6 34.2 367
(215 W) 1 7.44 80.0
1 10.8
To convert from either W m-2 or µE m-2 s-1 to photometric units, multiply by the appropriate factor." Here is the hyperlink:
http://www.madsci.org/posts/archive...36947.Ph.r.html
SO TO REPEAT The approximate conversion factors given below will help to convert absolute energy units or irradiance units (PAR)
as recommended by the plant scientist into illuminance
or photometric values (lux). That is what you specifically said could not be done.
Charmed by your graciousness!