2007-05-02; 19:20 (solar altitude 1.9)
direct sun
Corrected data with value at 290nm converted to zero to loer baseline, and all negative values to zero
Spectrum 439: 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 | ( 0.4 ; 0.38 ) | ( 0.55 ; 0.34 ) | ( 0.43 ; 0.31 ; 0.19 ) |
| CCT | 3500 Kelvin | 3300 Kelvin | 3500 Kelvin |
| distance | 0.031 | 0.024 | |
| 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) 1850 µW/cm² = 18.5 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) 1860 µW/cm² = 18.6 W/m² UVB (EU) ( 280 nm - 315 nm) 0 µW/cm² = 0 W/m² UVB (US) ( 280 nm - 320 nm) 0 µW/cm² = 0 W/m² UVA+B ( 280 nm - 380 nm) 7.3 µW/cm² = 0.073 W/m² Solar UVB ( 290 nm - 315 nm) 0 µW/cm² = 0 W/m² UVA D3 regulating ( 315 nm - 335 nm) 0 µW/cm² = 0 W/m² UVA (EU) ( 315 nm - 380 nm) 7.3 µW/cm² = 0.073 W/m² UVA2 (medical definition) ( 320 nm - 340 nm) 0 µW/cm² = 0 W/m² UVA (US) ( 320 nm - 380 nm) 7.3 µW/cm² = 0.073 W/m² UVA1 (variant) ( 335 nm - 380 nm) 7.3 µW/cm² = 0.073 W/m² UVA1 (medical) ( 340 nm - 400 nm) 16.3 µW/cm² = 0.163 W/m² vis. UVA ( 350 nm - 380 nm) 6.95 µW/cm² = 0.0695 W/m² VIS Rep3 ( 350 nm - 600 nm) 473 µW/cm² = 4.73 W/m² VIS Rep4 ( 350 nm - 700 nm) 1020 µW/cm² = 10.2 W/m² purple ( 380 nm - 420 nm) 29.1 µW/cm² = 0.291 W/m² VIS ( 380 nm - 780 nm) 1540 µW/cm² = 15.4 W/m² VIS2 ( 400 nm - 680 nm) 876 µW/cm² = 8.76 W/m² PAR ( 400 nm - 700 nm) 1000 µW/cm² = 10 W/m² tmp ( 400 nm - 1100 nm) 1840 µW/cm² = 18.4 W/m² blue ( 420 nm - 490 nm) 126 µW/cm² = 1.26 W/m² green ( 490 nm - 575 nm) 235 µW/cm² = 2.35 W/m² yellow ( 575 nm - 585 nm) 29.6 µW/cm² = 0.296 W/m² orange ( 585 nm - 650 nm) 261 µW/cm² = 2.61 W/m² red ( 650 nm - 780 nm) 860 µW/cm² = 8.6 W/m² IRA ( 700 nm - 1400 nm) 838 µW/cm² = 8.38 W/m² IR2 ( 720 nm - 1100 nm) 707 µW/cm² = 7.07 W/m² IRB ( 1400 nm - 3000 nm) 0 µW/cm² = 0 W/m²
Actionspectra
Erythema 0.00173 UV-Index Pyrimidine dimerization of DNA 0.000928 µW/cm² Photoceratitis 0 µW/cm² Photoconjunctivitis 0 µW/cm² DNA Damage 4.5E-6 Vitamin D3 0 µW/cm² Photosynthesis 734 µW/cm² Luminosity 2370 lx Human L-Cone 366 µW/cm² Human M-Cone 269 µW/cm² Human S-Cone 99.9 µW/cm² CIE X 350 µW/cm² CIE Y 328 µW/cm² CIE Z 191 µW/cm² PAR 5000000 mol photons Extinction preD3 0 e-3*m²/mol Extinction Tachysterol 0 e-3*m²/mol Exctincition PreD3 5.23 m²/mol Extinction Lumisterol 0 m²/mol Exctincition Tachysterol 94.6 m²/mol Extinction 7DHC 0 m²/mol L-Cone 338 µW/cm² M-Cone 247 µW/cm² S-Cone 152 µW/cm² U-Cone 50 µW/cm² UVR - ICNIRP 2004 0.00116 Rel Biol Eff Melatonin Supression 166 µW/cm² Blue Light Hazard 113 µW/cm² (47.7 µW/cm² per 1000 lx) CIE 174:2006 PreVit D3 0 µW/cm² Lumen Reptil 2010 "pseudo-lx" Vitamin D3 Degradation 0 µW/cm² Actinic UV 0.00115 µW/cm² (0.00488 mW/klm) Exctincition Lumisterol 0 m²/mol Exctincition 7DHC 0 m²/mol Exctincition Toxisterols 4.86 m²/mol
Broadbandmeters
Solarmeter 6.2 (UVB, pre 2010) 0.0604 µW/cm² Solarmeter 6.5 (UV-Index, pre 2010) 0.000615 Leybold UVB 0 µW/cm² Leybold UVA 5.61 µW/cm² Leybold UVC 0 µW/cm² DeltaOhm UVB 0.0227 µW/cm² DeltaOhm UVC 0 µW/cm² Vernier UVB 0 µW/cm² Vernier UVA 2.35 µW/cm² Gröbel UVA 5.53 µW/cm² Gröbel UVB 0.00178 µW/cm² Gröbel UVC 0 µW/cm² Luxmeter 2260 lx Solarmeter 6.4 (D3) 0.00192 IU/min UVX-31 0.249 µW/cm² IL UVB 2.58E-5 µW/cm² IL UVA 7.07 µW/cm² Solarmeter 6.5 (UVI, post 2010) 0.0002 UV-Index Solarmeter 6.2 (UVB, post 2010) 0.00191 µW/cm² (Solarmeter Ratio = 9.53) Solarmeter AlGaN 6.5 UVI sensor 0.00232 UV Index GenUV 7.1 UV-Index 0.00269 UV-Index Solarmeter 10.0 (Global Power) (manuf.) 25.4 W/m² Solarmeter 4.0 (UVA) 0.163 mW/cm² LS122 (manuf.) 0.0956 W/m² ISM400 (first guess) 26.2 W/m² LS122 (assumption) 1.19 W/m² ISM400_new 25.7 W/m² Solarmeter 10.0 (Global Power) (assumption) 25.9 W/m²