Spectrum from picture on homepage
One must assume that the wavelength-scale of the spectrum is wrong as there are no mercury lines at 665, 595 and 485
Spectrum 107: SW-M-13 EditDelete
Spectrum from picture on homepage
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|Ballast||- no ballast or default/unknown ballast -|
Colorimetry is the science to describe physically the human color perception. The wavelength range 380 nm - 780 nm is visible to humans and detected by three different photoreceptors. Many Reptiles see the range 350 nm - 800 nm and have an additional UV photoreceptor in their retina.
WARNING: The measurement range (350 - 800 nm) is not sufficient for this evaluation! Data is only available in the range 350 - 750 nm. Results are shown anyway but should be ignored by anyone except experts.
Whereas a spectrometer measures the intensity in every tiny wavelength interval resulting in thousands of individual intensities, the human eye only measures three intensities detected by the three cones. The same is true for the reptile eye with usually three or four photoreceptors. Effectively the detailled spectrum displayed above reduces to a much compacter bar graph displayed below. The photoreceptor sensitivites from these L-Cone, M-Cone, S-Cone, and U-Cone are used, they are chosen as an average of measured reptile photoreceptor sensitivity curves. The bar graph also shows as reference the intensity seen by the three or four photoreceptors for average sunlight (id 1).
From these three numbers the colour coordinate and the correlated colour temperature for humans are calculated using the CIE standard method. I adapted this concept to a "3 cone reptile (M,S,U)" and a "4 cone reptile (L,M,S,U)". I am sure, that this adaption to other colour spaces makes sense mathematically and this is also done in scientific research regarding colour vision of animals, however I have not seen calculation of colour temperatures for other animals in the scientific literature. Even if it is hypothetical, at least this shows, how arbitrary the colour temperature is, and that the colour temperature calculated for humans does not apply to reptiles. The colour spaces also show the colour coordinates of different phases of daylight ((ids 1, 338 – 451, 511 – 513 ), indicated by crosses, coloured in the appriximate colour perceived by a human.
|Human (CIE)||3 cone reptile||4 cone reptile|
|Colour Coordinate||( 0.39 ; 0.45 )||( 0.69 ; 0.2 )||( 0.44 ; 0.39 ; 0.12 )|
|CCT||4200 Kelvin||2200 Kelvin||3500 Kelvin|
|colour space||3-D-graph not implemented yet|
Vitamin D3 is produced by UVB radiation around 300 nm. 7DHC/ProD3 present in the skin is converted to PreD3 when absorbing an UV photon. PreD3 can be converted back to ProD3, to Lumisterol, or to Tachysterol when absorbing another UV photon or can be converted to Vitamin D3 in a warm environment.
The equilibrium of the photoproducts depends on the actual UV spectrum in the range 250 nm - 340 nm. With knowledge of the conversion probabilities and absorption spectra of 7DHC, PreD3, Tachysterol, and Lumisterol it is possible to calculate the ratio of photoproducts in equilibrium. This is based on scientific literature , however the constants that are used for the calculation are not well calibrated with experiments. It is therefore not a solid method, but I consider it useful as a first guess how natural a UV spectrum is.
Caveat: This evaluation is extremely sensitive to the qualitiy of the spectral measurement in the range 220 nm - 340 nm. High quality spectrometers and good background calibration is needed to get the noise below 300 nm low enough for this evaluation. Please check at least the UV graph above for noise.
The ratio of the two solarmeters 6.2 (UVB) and 6.5 (UV index) readings has proven a useful and very simply number to acess the spectral shape in the vitamin-d3-active region.
The calculation method is a numerical implementation (Simpson's rule) of the formula
To learn more about calculating effective irradiances and radiometers I recommend this excellent report on UVB meters: Characterizing the Performance of Integral Measuring UV-Meters (pdf).
The numbers in the following tables can also be used to estimate certain (effective) irradiances from radiomer readings. Example: If the database lists
- range: UVB (US) = 13.8 µW/cm²
- radiometer: Solarmeter 6.2 = 19.6 µW/cm²
total ( 0 nm - 0 nm) 20200 µW/cm² = 202 W/m² UVC ( 0 nm - 280 nm) 0 µW/cm² = 0 W/m² UVB (EU) ( 280 nm - 315 nm) 0 µW/cm² = 0 W/m² UVB (US) ( 280 nm - 320 nm) 0 µW/cm² = 0 W/m² UVA+B ( 280 nm - 380 nm) 62.1 µW/cm² = 0.621 W/m² UVA1 ( 315 nm - 335 nm) 0 µW/cm² = 0 W/m² UVA (EU) ( 315 nm - 400 nm) 344 µW/cm² = 3.44 W/m² UVA1(US) ( 320 nm - 350 nm) 0 µW/cm² = 0 W/m² UVA (US) ( 320 nm - 400 nm) 344 µW/cm² = 3.44 W/m² UVA2 ( 335 nm - 380 nm) 62.1 µW/cm² = 0.621 W/m² vis. UVA ( 350 nm - 380 nm) 62.1 µW/cm² = 0.621 W/m² VIS Rep3 ( 350 nm - 600 nm) 12600 µW/cm² = 126 W/m² VIS Rep4 ( 350 nm - 700 nm) 19200 µW/cm² = 192 W/m² purple ( 380 nm - 420 nm) 767 µW/cm² = 7.67 W/m² VIS ( 380 nm - 780 nm) 20200 µW/cm² = 202 W/m² PAR ( 400 nm - 700 nm) 18800 µW/cm² = 188 W/m² blue ( 420 nm - 490 nm) 2710 µW/cm² = 27.1 W/m² green ( 490 nm - 575 nm) 6300 µW/cm² = 63 W/m² yellow ( 575 nm - 585 nm) 549 µW/cm² = 5.49 W/m² orange ( 585 nm - 650 nm) 4910 µW/cm² = 49.1 W/m² red ( 650 nm - 780 nm) 4960 µW/cm² = 49.6 W/m² IRA ( 700 nm - 1400 nm) 1060 µW/cm² = 10.6 W/m² IRB ( 1400 nm - 3000 nm) 0 µW/cm² = 0 W/m²
Erythema 0.0263 UV-Index Pyrimidine dimerization of DNA 0.0037 µW/cm² Photoceratitis 0 µW/cm² Photoconjunctivitis 0 µW/cm² DNA Damage 2.54E-5 Vitamin D3 0 µW/cm² Photosynthesis 12400 µW/cm² Luminosity 60500 lx Human L-Cone 9100 µW/cm² Human M-Cone 7400 µW/cm² Human S-Cone 1570 µW/cm² CIE X 7370 µW/cm² CIE Y 8460 µW/cm² CIE Z 3090 µW/cm² PAR 90800000 mol photons Extinction preD3 0 e-3*m²/mol Extinction Tachysterol 0 e-3*m²/mol Extinction Lumisterol 0 m²/mol Extinction 7DHC 0 m²/mol L-Cone 7890 µW/cm² M-Cone 7000 µW/cm² S-Cone 2090 µW/cm² U-Cone 1100 µW/cm² UVR - ICNIRP 2004 0.0171 Rel Biol Eff Melatonin Supression 3540 µW/cm² Blue Light Hazard 1940 µW/cm² (32.1 µW/cm² per 1000 lx) CIE 174:2006 PreVit D3 0 µW/cm² Lumen Reptil 47100 "pseudo-lx" Vitamin D3 Degradation 0 µW/cm² Actinic UV 0.0171 µW/cm²
Solarmeter 6.2 (UVB, pre 2010) 1.23 µW/cm² Solarmeter 6.5 (UV-Index, pre 2010) 0.00658 Leybold UVB 0 µW/cm² Leybold UVA 68.1 µW/cm² Leybold UVC 0 µW/cm² DeltaOhm UVB 0.00371 µW/cm² DeltaOhm UVC 0 µW/cm² Vernier UVB 0 µW/cm² Vernier UVA 22.9 µW/cm² Gröbel UVA 49.3 µW/cm² Gröbel UVB -0.00227 µW/cm² Gröbel UVC 0 µW/cm² Solarmeter 6.4 (D3) 0.0206 IU/min UVX-31 1.12 µW/cm² IL UVB 0.000167 µW/cm² IL UVA 76.6 µW/cm² Solarmeter 6.5 (UVI, post 2010) 0.00129 UV-Index Solarmeter 6.2 (UVB, post 2010) 0.0171 µW/cm² (Solarmeter Ratio = 13.3) Solarmeter AlGaN 6.5 UVI sensor 0.0388 UV Index GenUV 7.1 UV-Index 0.0547 UV-Index Solarmeter 10.0 (Global Power) 232 W/m² Solarmeter 4.0 (UVA) 3.04 mW/cm²