2008-06-19; 13:22 (solar altitude 61.6)
overcast sky
with baseline at 293nm set at zero
Spectrum 436: SUN Edit
DeleteMeasurement
| Brand |
other other |
|---|---|
| Lamp Product |
Sun Direct sunlight |
| Lamp ID |
SUN (01/2000) |
| Spectrometer | USB2000+ |
| 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.
WARNING: The measurement range (350 - 800 nm) is not sufficient for this evaluation! Data is only available in the range 290.19 - 750.27 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 | |
|---|---|---|---|
| Cone Excitation | |||
| Colour Coordinate | ( 0.3 ; 0.31 ) | ( 0.37 ; 0.39 ) | ( 0.23 ; 0.29 ; 0.3 ) |
| CCT | 7500 Kelvin | 5400 Kelvin | 6100 Kelvin |
| distance | 0.043 | 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) 12100 µW/cm² = 121 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) 12100 µW/cm² = 121 W/m² UVB (EU) ( 280 nm - 315 nm) 36.9 µW/cm² = 0.369 W/m² UVB (US) ( 280 nm - 320 nm) 74.4 µW/cm² = 0.744 W/m² UVA+B ( 280 nm - 380 nm) 1100 µW/cm² = 11 W/m² Solar UVB ( 290 nm - 315 nm) 36.9 µW/cm² = 0.369 W/m² UVA D3 regulating ( 315 nm - 335 nm) 229 µW/cm² = 2.29 W/m² UVA (EU) ( 315 nm - 380 nm) 1060 µW/cm² = 10.6 W/m² UVA2 (medical definition) ( 320 nm - 340 nm) 270 µW/cm² = 2.7 W/m² UVA (US) ( 320 nm - 380 nm) 1020 µW/cm² = 10.2 W/m² UVA1 (variant) ( 335 nm - 380 nm) 833 µW/cm² = 8.33 W/m² UVA1 (medical) ( 340 nm - 400 nm) 1170 µW/cm² = 11.7 W/m² vis. UVA ( 350 nm - 380 nm) 594 µW/cm² = 5.94 W/m² VIS Rep3 ( 350 nm - 600 nm) 8020 µW/cm² = 80.2 W/m² VIS Rep4 ( 350 nm - 700 nm) 10500 µW/cm² = 105 W/m² purple ( 380 nm - 420 nm) 1110 µW/cm² = 11.1 W/m² VIS ( 380 nm - 780 nm) 11000 µW/cm² = 110 W/m² VIS2 ( 400 nm - 680 nm) 9090 µW/cm² = 90.9 W/m² PAR ( 400 nm - 700 nm) 9540 µW/cm² = 95.4 W/m² tmp ( 400 nm - 1100 nm) 10600 µW/cm² = 106 W/m² blue ( 420 nm - 490 nm) 2810 µW/cm² = 28.1 W/m² green ( 490 nm - 575 nm) 2790 µW/cm² = 27.9 W/m² yellow ( 575 nm - 585 nm) 295 µW/cm² = 2.95 W/m² orange ( 585 nm - 650 nm) 1770 µW/cm² = 17.7 W/m² red ( 650 nm - 780 nm) 2250 µW/cm² = 22.5 W/m² IRA ( 700 nm - 1400 nm) 1060 µW/cm² = 10.6 W/m² IR2 ( 720 nm - 1100 nm) 629 µW/cm² = 6.29 W/m² IRB ( 1400 nm - 3000 nm) 0 µW/cm² = 0 W/m²
Actionspectra
Erythema 2.41 UV-Index Pyrimidine dimerization of DNA 25.8 µW/cm² Photoceratitis 3.48 µW/cm² Photoconjunctivitis 0.0857 µW/cm² DNA Damage 0.285 Vitamin D3 8.77 µW/cm² Photosynthesis 6900 µW/cm² Luminosity 24000 lx Human L-Cone 3550 µW/cm² Human M-Cone 3070 µW/cm² Human S-Cone 2290 µW/cm² CIE X 3240 µW/cm² CIE Y 3320 µW/cm² CIE Z 4230 µW/cm² PAR 44400000 mol photons Extinction preD3 78.9 e-3*m²/mol Extinction Tachysterol 295 e-3*m²/mol Exctincition PreD3 42800 m²/mol Extinction Lumisterol 9.17 m²/mol Exctincition Tachysterol 500000 m²/mol Extinction 7DHC 9.25 m²/mol L-Cone 2970 µW/cm² M-Cone 3690 µW/cm² S-Cone 3800 µW/cm² U-Cone 2370 µW/cm² UVR - ICNIRP 2004 1.85 Rel Biol Eff Melatonin Supression 3410 µW/cm² Blue Light Hazard 2640 µW/cm² (110 µW/cm² per 1000 lx) CIE 174:2006 PreVit D3 9.48 µW/cm² Lumen Reptil 28700 "pseudo-lx" Vitamin D3 Degradation 15.4 µW/cm² Actinic UV 1.85 µW/cm² (0.769 mW/klm) Exctincition Lumisterol 14000 m²/mol Exctincition 7DHC 11600 m²/mol Exctincition Toxisterols 9880 m²/mol
Broadbandmeters
Solarmeter 6.2 (UVB, pre 2010) 105 µW/cm² Solarmeter 6.5 (UV-Index, pre 2010) 2.75 Leybold UVB 68 µW/cm² Leybold UVA 768 µW/cm² Leybold UVC 0.00604 µW/cm² DeltaOhm UVB 251 µW/cm² DeltaOhm UVC 25.7 µW/cm² Vernier UVB 17 µW/cm² Vernier UVA 589 µW/cm² Gröbel UVA 868 µW/cm² Gröbel UVB 30.8 µW/cm² Gröbel UVC -0.0161 µW/cm² Luxmeter 24500 lx Solarmeter 6.4 (D3) 8.59 IU/min UVX-31 294 µW/cm² IL UVB 0.0503 µW/cm² IL UVA 896 µW/cm² Solarmeter 6.5 (UVI, post 2010) 2.29 UV-Index Solarmeter 6.2 (UVB, post 2010) 77 µW/cm² (Solarmeter Ratio = 33.6) Solarmeter AlGaN 6.5 UVI sensor 33.2 UV Index GenUV 7.1 UV-Index 2.21 UV-Index Solarmeter 10.0 (Global Power) (manuf.) 120 W/m² Solarmeter 4.0 (UVA) 14.5 mW/cm² LS122 (manuf.) 0 W/m² ISM400 (first guess) 85.7 W/m² LS122 (assumption) 3.85 W/m² ISM400_new 72 W/m² Solarmeter 10.0 (Global Power) (assumption) 113 W/m²