2007-05-02; 18:22 (solar altitude 10.2)
direct sun
Corrected data with value at 290nm converted to zero to loer baseline, and all negative values to zero
Spectrum 441: SUN Edit
DeleteMeasurement
| Brand |
other other |
|---|---|
| Lamp Product |
Sun Direct sunlight |
| Lamp ID |
SUN (01/2000) |
| Spectrometer | USB 2000 |
| Ballast | - no ballast or default/unknown ballast - |
| Reflector | |
| Distance | 0 cm |
| Age | 0 hours |
| Originator (measurement) | Frances Baines |
Database entry created:
Sarina Wunderlich
12/Jan/2012 ; updated:
Sarina Wunderlich
12/Jan/2012
Colorimetry
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.
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 | |
|---|---|---|---|
| Cone Excitation | |||
| Colour Coordinate | ( 0.36 ; 0.37 ) | ( 0.53 ; 0.35 ) | ( 0.37 ; 0.33 ; 0.22 ) |
| CCT | 4500 Kelvin | 3500 Kelvin | 4000 Kelvin |
| distance | 0.039 | 0.044 | |
| colour space | 3-D-graph not implemented yet |
Vitamin D3 Analysis
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.
This process prevents any overdose of vitamin D3 from UV radiation with a spectrum similar to sunlight. As a comparison the solar spectra at 20°(id:14) and at 85°(id:21) solar angle are shown.
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.
Effective Irradiances
Effective irradiances are calculated for all ranges, actionspectra and radiometers currently present in this database.
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
Ranges
total ( 0 nm - 0 nm) 29400 µW/cm² = 294 W/m² UVC ( 0 nm - 280 nm) 0 µW/cm² = 0 W/m² non-terrestrial ( 0 nm - 290 nm) 0 µW/cm² = 0 W/m² total2 ( 250 nm - 880 nm) 29300 µW/cm² = 293 W/m² UVB (EU) ( 280 nm - 315 nm) 0.765 µW/cm² = 0.00765 W/m² UVB (US) ( 280 nm - 320 nm) 2.59 µW/cm² = 0.0259 W/m² UVA+B ( 280 nm - 380 nm) 280 µW/cm² = 2.8 W/m² Solar UVB ( 290 nm - 315 nm) 0.765 µW/cm² = 0.00765 W/m² UVA D3 regulating ( 315 nm - 335 nm) 27.9 µW/cm² = 0.279 W/m² UVA (EU) ( 315 nm - 380 nm) 279 µW/cm² = 2.79 W/m² UVA2 (medical definition) ( 320 nm - 340 nm) 40.7 µW/cm² = 0.407 W/m² UVA (US) ( 320 nm - 380 nm) 277 µW/cm² = 2.77 W/m² UVA1 (variant) ( 335 nm - 380 nm) 251 µW/cm² = 2.51 W/m² UVA1 (medical) ( 340 nm - 400 nm) 465 µW/cm² = 4.65 W/m² vis. UVA ( 350 nm - 380 nm) 201 µW/cm² = 2.01 W/m² VIS Rep3 ( 350 nm - 600 nm) 10800 µW/cm² = 108 W/m² VIS Rep4 ( 350 nm - 700 nm) 17800 µW/cm² = 178 W/m² purple ( 380 nm - 420 nm) 723 µW/cm² = 7.23 W/m² VIS ( 380 nm - 780 nm) 22700 µW/cm² = 227 W/m² PAR ( 400 nm - 700 nm) 17300 µW/cm² = 173 W/m² blue ( 420 nm - 490 nm) 3140 µW/cm² = 31.4 W/m² green ( 490 nm - 575 nm) 5180 µW/cm² = 51.8 W/m² yellow ( 575 nm - 585 nm) 636 µW/cm² = 6.36 W/m² orange ( 585 nm - 650 nm) 4290 µW/cm² = 42.9 W/m² red ( 650 nm - 780 nm) 8700 µW/cm² = 87 W/m² IRA ( 700 nm - 1400 nm) 11600 µW/cm² = 116 W/m² IRB ( 1400 nm - 3000 nm) 0 µW/cm² = 0 W/m²
Actionspectra
Erythema 0.346 UV-Index Pyrimidine dimerization of DNA 0.999 µW/cm² Photoceratitis 0.418 µW/cm² Photoconjunctivitis 0.0278 µW/cm² DNA Damage 0.096 Vitamin D3 0.637 µW/cm² Photosynthesis 12200 µW/cm² Luminosity 47800 lx Human L-Cone 7230 µW/cm² Human M-Cone 5760 µW/cm² Human S-Cone 2490 µW/cm² CIE X 6490 µW/cm² CIE Y 6640 µW/cm² CIE Z 4730 µW/cm² PAR 83500000 mol photons Extinction preD3 5.14 e-3*m²/mol Extinction Tachysterol 22.2 e-3*m²/mol Exctincition PreD3 4240 m²/mol Extinction Lumisterol 2.2 m²/mol Exctincition Tachysterol 51400 m²/mol Extinction 7DHC 3.31 m²/mol L-Cone 6350 µW/cm² M-Cone 5700 µW/cm² S-Cone 3820 µW/cm² U-Cone 1270 µW/cm² UVR - ICNIRP 2004 0.404 Rel Biol Eff Melatonin Supression 4050 µW/cm² Blue Light Hazard 2800 µW/cm² (58.5 µW/cm² per 1000 lx) CIE 174:2006 PreVit D3 0.622 µW/cm² Lumen Reptil 42500 "pseudo-lx" Vitamin D3 Degradation 1 µW/cm² Actinic UV 0.404 µW/cm² (0.0845 mW/klm) Exctincition Lumisterol 2670 m²/mol Exctincition 7DHC 3770 m²/mol Exctincition Toxisterols 1190 m²/mol
Broadbandmeters
Solarmeter 6.2 (UVB, pre 2010) 7.85 µW/cm² Solarmeter 6.5 (UV-Index, pre 2010) 0.246 Leybold UVB 3.57 µW/cm² Leybold UVA 215 µW/cm² Leybold UVC 0.00286 µW/cm² DeltaOhm UVB 29 µW/cm² DeltaOhm UVC 2.17 µW/cm² Vernier UVB 0.465 µW/cm² Vernier UVA 125 µW/cm² Gröbel UVA 223 µW/cm² Gröbel UVB 1.89 µW/cm² Gröbel UVC 0.0012 µW/cm² Solarmeter 6.4 (D3) 0.768 IU/min UVX-31 40 µW/cm² IL UVB 0.00513 µW/cm² IL UVA 254 µW/cm² Solarmeter 6.5 (UVI, post 2010) 0.146 UV-Index Solarmeter 6.2 (UVB, post 2010) 5.72 µW/cm² (Solarmeter Ratio = 39.1) Solarmeter AlGaN 6.5 UVI sensor 1.03 UV Index GenUV 7.1 UV-Index 0.152 UV-Index Solarmeter 10.0 (Global Power) 387 W/m² Solarmeter 4.0 (UVA) 5 mW/cm² LS122 7.32 W/m² ISM400 387 W/m²