2007-05-03; 14:32 (solar altitude 44.1)
direct sun
Corrected data with value at 290nm converted to zero to loer baseline, and all negative values to zero
Spectrum 449: 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 | ( 0.33 ; 0.34 ) | ( 0.43 ; 0.38 ) | ( 0.29 ; 0.3 ; 0.27 ) |
| CCT | 5500 Kelvin | 4500 Kelvin | 4900 Kelvin |
| distance | 0.041 | 0.038 | |
| 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) 51400 µW/cm² = 514 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) 51300 µW/cm² = 513 W/m² UVB (EU) ( 280 nm - 315 nm) 36.2 µW/cm² = 0.362 W/m² UVB (US) ( 280 nm - 320 nm) 82 µW/cm² = 0.82 W/m² UVA+B ( 280 nm - 380 nm) 1790 µW/cm² = 17.9 W/m² Solar UVB ( 290 nm - 315 nm) 36.2 µW/cm² = 0.362 W/m² UVA D3 regulating ( 315 nm - 335 nm) 304 µW/cm² = 3.04 W/m² UVA (EU) ( 315 nm - 380 nm) 1750 µW/cm² = 17.5 W/m² UVA2 (medical definition) ( 320 nm - 340 nm) 370 µW/cm² = 3.7 W/m² UVA (US) ( 320 nm - 380 nm) 1710 µW/cm² = 17.1 W/m² UVA1 (variant) ( 335 nm - 380 nm) 1450 µW/cm² = 14.5 W/m² UVA1 (medical) ( 340 nm - 400 nm) 2310 µW/cm² = 23.1 W/m² vis. UVA ( 350 nm - 380 nm) 1090 µW/cm² = 10.9 W/m² VIS Rep3 ( 350 nm - 600 nm) 25000 µW/cm² = 250 W/m² VIS Rep4 ( 350 nm - 700 nm) 35800 µW/cm² = 358 W/m² purple ( 380 nm - 420 nm) 2730 µW/cm² = 27.3 W/m² VIS ( 380 nm - 780 nm) 41700 µW/cm² = 417 W/m² PAR ( 400 nm - 700 nm) 33800 µW/cm² = 338 W/m² blue ( 420 nm - 490 nm) 8010 µW/cm² = 80.1 W/m² green ( 490 nm - 575 nm) 10200 µW/cm² = 102 W/m² yellow ( 575 nm - 585 nm) 1220 µW/cm² = 12.2 W/m² orange ( 585 nm - 650 nm) 7370 µW/cm² = 73.7 W/m² red ( 650 nm - 780 nm) 12200 µW/cm² = 122 W/m² IRA ( 700 nm - 1400 nm) 14900 µW/cm² = 149 W/m² IRB ( 1400 nm - 3000 nm) 0 µW/cm² = 0 W/m²
Actionspectra
Erythema 2.04 UV-Index Pyrimidine dimerization of DNA 27.2 µW/cm² Photoceratitis 2.6 µW/cm² Photoconjunctivitis 0.0313 µW/cm² DNA Damage 0.102 Vitamin D3 7.01 µW/cm² Photosynthesis 24000 µW/cm² Luminosity 91100 lx Human L-Cone 13600 µW/cm² Human M-Cone 11300 µW/cm² Human S-Cone 6510 µW/cm² CIE X 12300 µW/cm² CIE Y 12600 µW/cm² CIE Z 12100 µW/cm² PAR 160000000 mol photons Extinction preD3 82.9 e-3*m²/mol Extinction Tachysterol 315 e-3*m²/mol Exctincition PreD3 47100 m²/mol Extinction Lumisterol 4.36 m²/mol Exctincition Tachysterol 580000 m²/mol Extinction 7DHC 2.82 m²/mol L-Cone 11700 µW/cm² M-Cone 12100 µW/cm² S-Cone 10600 µW/cm² U-Cone 5310 µW/cm² UVR - ICNIRP 2004 1.21 Rel Biol Eff Melatonin Supression 9980 µW/cm² Blue Light Hazard 7440 µW/cm² (81.8 µW/cm² per 1000 lx) CIE 174:2006 PreVit D3 7.49 µW/cm² Lumen Reptil 93200 "pseudo-lx" Vitamin D3 Degradation 17.1 µW/cm² Actinic UV 1.22 µW/cm² (0.134 mW/klm) Exctincition Lumisterol 8830 m²/mol Exctincition 7DHC 4250 m²/mol Exctincition Toxisterols 12600 m²/mol
Broadbandmeters
Solarmeter 6.2 (UVB, pre 2010) 126 µW/cm² Solarmeter 6.5 (UV-Index, pre 2010) 2.34 Leybold UVB 77.9 µW/cm² Leybold UVA 1290 µW/cm² Leybold UVC 0.00127 µW/cm² DeltaOhm UVB 327 µW/cm² DeltaOhm UVC 31.6 µW/cm² Vernier UVB 15.5 µW/cm² Vernier UVA 887 µW/cm² Gröbel UVA 1410 µW/cm² Gröbel UVB 32.9 µW/cm² Gröbel UVC -0.0241 µW/cm² Solarmeter 6.4 (D3) 7.32 IU/min UVX-31 397 µW/cm² IL UVB 0.0622 µW/cm² IL UVA 1510 µW/cm² Solarmeter 6.5 (UVI, post 2010) 2.06 UV-Index Solarmeter 6.2 (UVB, post 2010) 94.1 µW/cm² (Solarmeter Ratio = 45.6) Solarmeter AlGaN 6.5 UVI sensor 33.8 UV Index GenUV 7.1 UV-Index 2.53 UV-Index Solarmeter 10.0 (Global Power) 617 W/m² Solarmeter 4.0 (UVA) 26.6 mW/cm² LS122 8.56 W/m² ISM400 565 W/m²