2010-05-23; 13:39 (solar altitude 58.3)
direct sun
Spectrum 431: SUN Edit
DeleteMeasurement
| Brand |
other other |
|---|---|
| Lamp Product |
Sun Direct sunlight |
| Lamp ID |
SUN (01/2000) |
| Spectrometer | USB2000+ (2) |
| 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 | ( 0.32 ; 0.32 ) | ( 0.4 ; 0.39 ) | ( 0.27 ; 0.3 ; 0.29 ) |
| CCT | 6100 Kelvin | 4900 Kelvin | 5400 Kelvin |
| distance | 0.052 | 0.046 | |
| 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) 66600 µW/cm² = 666 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) 66500 µW/cm² = 665 W/m² UVB (EU) ( 280 nm - 315 nm) 87.6 µW/cm² = 0.876 W/m² UVB (US) ( 280 nm - 320 nm) 170 µW/cm² = 1.7 W/m² UVA+B ( 280 nm - 380 nm) 3120 µW/cm² = 31.2 W/m² Solar UVB ( 290 nm - 315 nm) 87.6 µW/cm² = 0.876 W/m² UVA D3 regulating ( 315 nm - 335 nm) 564 µW/cm² = 5.64 W/m² UVA (EU) ( 315 nm - 380 nm) 3030 µW/cm² = 30.3 W/m² UVA2 (medical definition) ( 320 nm - 340 nm) 681 µW/cm² = 6.81 W/m² UVA (US) ( 320 nm - 380 nm) 2950 µW/cm² = 29.5 W/m² UVA1 (variant) ( 335 nm - 380 nm) 2470 µW/cm² = 24.7 W/m² UVA1 (medical) ( 340 nm - 400 nm) 3720 µW/cm² = 37.2 W/m² vis. UVA ( 350 nm - 380 nm) 1840 µW/cm² = 18.4 W/m² VIS Rep3 ( 350 nm - 600 nm) 34600 µW/cm² = 346 W/m² VIS Rep4 ( 350 nm - 700 nm) 48500 µW/cm² = 485 W/m² purple ( 380 nm - 420 nm) 4190 µW/cm² = 41.9 W/m² VIS ( 380 nm - 780 nm) 54800 µW/cm² = 548 W/m² PAR ( 400 nm - 700 nm) 45200 µW/cm² = 452 W/m² blue ( 420 nm - 490 nm) 12000 µW/cm² = 120 W/m² green ( 490 nm - 575 nm) 12800 µW/cm² = 128 W/m² yellow ( 575 nm - 585 nm) 1500 µW/cm² = 15 W/m² orange ( 585 nm - 650 nm) 9590 µW/cm² = 95.9 W/m² red ( 650 nm - 780 nm) 14700 µW/cm² = 147 W/m² IRA ( 700 nm - 1400 nm) 16800 µW/cm² = 168 W/m² IRB ( 1400 nm - 3000 nm) 0 µW/cm² = 0 W/m²
Actionspectra
Erythema 4.64 UV-Index Pyrimidine dimerization of DNA 61.3 µW/cm² Photoceratitis 6.27 µW/cm² Photoconjunctivitis 0.0693 µW/cm² DNA Damage 0.223 Vitamin D3 18 µW/cm² Photosynthesis 32600 µW/cm² Luminosity 116000 lx Human L-Cone 17400 µW/cm² Human M-Cone 14400 µW/cm² Human S-Cone 9750 µW/cm² CIE X 16100 µW/cm² CIE Y 16000 µW/cm² CIE Z 18100 µW/cm² PAR 213000000 mol photons Extinction preD3 178 e-3*m²/mol Extinction Tachysterol 661 e-3*m²/mol Exctincition PreD3 96700 m²/mol Extinction Lumisterol 11.2 m²/mol Exctincition Tachysterol 1160000 m²/mol Extinction 7DHC 6.38 m²/mol L-Cone 14800 µW/cm² M-Cone 16400 µW/cm² S-Cone 16000 µW/cm² U-Cone 8310 µW/cm² UVR - ICNIRP 2004 2.79 Rel Biol Eff Melatonin Supression 14600 µW/cm² Blue Light Hazard 11200 µW/cm² (96.2 µW/cm² per 1000 lx) CIE 174:2006 PreVit D3 19.7 µW/cm² Lumen Reptil 128000 "pseudo-lx" Vitamin D3 Degradation 35.9 µW/cm² Actinic UV 2.8 µW/cm² (0.241 mW/klm) Exctincition Lumisterol 21200 m²/mol Exctincition 7DHC 9750 m²/mol Exctincition Toxisterols 24100 m²/mol
Broadbandmeters
Solarmeter 6.2 (UVB, pre 2010) 252 µW/cm² Solarmeter 6.5 (UV-Index, pre 2010) 5.69 Leybold UVB 162 µW/cm² Leybold UVA 2220 µW/cm² Leybold UVC 0.00143 µW/cm² DeltaOhm UVB 617 µW/cm² DeltaOhm UVC 59.4 µW/cm² Vernier UVB 40 µW/cm² Vernier UVA 1580 µW/cm² Gröbel UVA 2470 µW/cm² Gröbel UVB 72.1 µW/cm² Gröbel UVC -0.0492 µW/cm² Solarmeter 6.4 (D3) 17.8 IU/min UVX-31 742 µW/cm² IL UVB 0.122 µW/cm² IL UVA 2610 µW/cm² Solarmeter 6.5 (UVI, post 2010) 5 UV-Index Solarmeter 6.2 (UVB, post 2010) 184 µW/cm² (Solarmeter Ratio = 36.9) Solarmeter AlGaN 6.5 UVI sensor 77.7 UV Index GenUV 7.1 UV-Index 5.35 UV-Index Solarmeter 10.0 (Global Power) 770 W/m² Solarmeter 4.0 (UVA) 44.2 mW/cm² LS122 9.49 W/m² ISM400 680 W/m²