2007-05-03; 16:36 (solar altitude 26.6)
direct sun
Corrected data with value at 290nm converted to zero to loer baseline, and all negative values to zero
Spectrum 450: 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 | ( 0.34 ; 0.35 ) | ( 0.46 ; 0.37 ) | ( 0.31 ; 0.31 ; 0.26 ) |
| CCT | 5200 Kelvin | 4200 Kelvin | 4600 Kelvin |
| distance | 0.041 | 0.039 | |
| 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) 36600 µW/cm² = 366 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) 36500 µW/cm² = 365 W/m² UVB (EU) ( 280 nm - 315 nm) 6.88 µW/cm² = 0.0688 W/m² UVB (US) ( 280 nm - 320 nm) 23.3 µW/cm² = 0.233 W/m² UVA+B ( 280 nm - 380 nm) 908 µW/cm² = 9.08 W/m² Solar UVB ( 290 nm - 315 nm) 6.88 µW/cm² = 0.0688 W/m² UVA D3 regulating ( 315 nm - 335 nm) 135 µW/cm² = 1.35 W/m² UVA (EU) ( 315 nm - 380 nm) 901 µW/cm² = 9.01 W/m² UVA2 (medical definition) ( 320 nm - 340 nm) 173 µW/cm² = 1.73 W/m² UVA (US) ( 320 nm - 380 nm) 885 µW/cm² = 8.85 W/m² UVA1 (variant) ( 335 nm - 380 nm) 766 µW/cm² = 7.66 W/m² UVA1 (medical) ( 340 nm - 400 nm) 1260 µW/cm² = 12.6 W/m² vis. UVA ( 350 nm - 380 nm) 587 µW/cm² = 5.87 W/m² VIS Rep3 ( 350 nm - 600 nm) 16300 µW/cm² = 163 W/m² VIS Rep4 ( 350 nm - 700 nm) 24300 µW/cm² = 243 W/m² purple ( 380 nm - 420 nm) 1600 µW/cm² = 16 W/m² VIS ( 380 nm - 780 nm) 29100 µW/cm² = 291 W/m² PAR ( 400 nm - 700 nm) 23100 µW/cm² = 231 W/m² blue ( 420 nm - 490 nm) 5130 µW/cm² = 51.3 W/m² green ( 490 nm - 575 nm) 6980 µW/cm² = 69.8 W/m² yellow ( 575 nm - 585 nm) 842 µW/cm² = 8.42 W/m² orange ( 585 nm - 650 nm) 5240 µW/cm² = 52.4 W/m² red ( 650 nm - 780 nm) 9280 µW/cm² = 92.8 W/m² IRA ( 700 nm - 1400 nm) 12000 µW/cm² = 120 W/m² IRB ( 1400 nm - 3000 nm) 0 µW/cm² = 0 W/m²
Actionspectra
Erythema 0.547 UV-Index Pyrimidine dimerization of DNA 6.73 µW/cm² Photoceratitis 0.444 µW/cm² Photoconjunctivitis 0.00715 µW/cm² DNA Damage 0.0269 Vitamin D3 0.953 µW/cm² Photosynthesis 16400 µW/cm² Luminosity 62900 lx Human L-Cone 9450 µW/cm² Human M-Cone 7740 µW/cm² Human S-Cone 4140 µW/cm² CIE X 8490 µW/cm² CIE Y 8730 µW/cm² CIE Z 7760 µW/cm² PAR 110000000 mol photons Extinction preD3 23.8 e-3*m²/mol Extinction Tachysterol 96.7 e-3*m²/mol Exctincition PreD3 16000 m²/mol Extinction Lumisterol 0.629 m²/mol Exctincition Tachysterol 211000 m²/mol Extinction 7DHC 0.647 m²/mol L-Cone 8150 µW/cm² M-Cone 8110 µW/cm² S-Cone 6650 µW/cm² U-Cone 3030 µW/cm² UVR - ICNIRP 2004 0.325 Rel Biol Eff Melatonin Supression 6440 µW/cm² Blue Light Hazard 4720 µW/cm² (74.9 µW/cm² per 1000 lx) CIE 174:2006 PreVit D3 0.837 µW/cm² Lumen Reptil 61900 "pseudo-lx" Vitamin D3 Degradation 5.37 µW/cm² Actinic UV 0.325 µW/cm² (0.0517 mW/klm) Exctincition Lumisterol 1740 m²/mol Exctincition 7DHC 939 m²/mol Exctincition Toxisterols 5150 m²/mol
Broadbandmeters
Solarmeter 6.2 (UVB, pre 2010) 43.7 µW/cm² Solarmeter 6.5 (UV-Index, pre 2010) 0.457 Leybold UVB 24.4 µW/cm² Leybold UVA 672 µW/cm² Leybold UVC 0.000565 µW/cm² DeltaOhm UVB 138 µW/cm² DeltaOhm UVC 12 µW/cm² Vernier UVB 2.22 µW/cm² Vernier UVA 439 µW/cm² Gröbel UVA 724 µW/cm² Gröbel UVB 9.26 µW/cm² Gröbel UVC -0.00702 µW/cm² Solarmeter 6.4 (D3) 1.43 IU/min UVX-31 174 µW/cm² IL UVB 0.0239 µW/cm² IL UVA 792 µW/cm² Solarmeter 6.5 (UVI, post 2010) 0.394 UV-Index Solarmeter 6.2 (UVB, post 2010) 34.5 µW/cm² (Solarmeter Ratio = 87.6) Solarmeter AlGaN 6.5 UVI sensor 7.27 UV Index GenUV 7.1 UV-Index 0.761 UV-Index Solarmeter 10.0 (Global Power) 455 W/m² Solarmeter 4.0 (UVA) 14.2 mW/cm² LS122 7.48 W/m² ISM400 431 W/m²