2010-05-23; 14:10 (solar altitude 56.6)
maple tree shade
Spectrum 435: 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 | ( 0.26 ; 0.27 ) | ( 0.29 ; 0.38 ) | ( 0.16 ; 0.24 ; 0.32 ) |
| CCT | 15000 Kelvin | 8000 Kelvin | 9500 Kelvin |
| distance | 0.045 | 0.048 | |
| 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) 3070 µW/cm² = 30.7 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) 3060 µW/cm² = 30.6 W/m² UVB (EU) ( 280 nm - 315 nm) 12.9 µW/cm² = 0.129 W/m² UVB (US) ( 280 nm - 320 nm) 24.6 µW/cm² = 0.246 W/m² UVA+B ( 280 nm - 380 nm) 302 µW/cm² = 3.02 W/m² Solar UVB ( 290 nm - 315 nm) 12.9 µW/cm² = 0.129 W/m² UVA D3 regulating ( 315 nm - 335 nm) 72.9 µW/cm² = 0.729 W/m² UVA (EU) ( 315 nm - 380 nm) 289 µW/cm² = 2.89 W/m² UVA2 (medical definition) ( 320 nm - 340 nm) 84.1 µW/cm² = 0.841 W/m² UVA (US) ( 320 nm - 380 nm) 277 µW/cm² = 2.77 W/m² UVA1 (variant) ( 335 nm - 380 nm) 216 µW/cm² = 2.16 W/m² UVA1 (medical) ( 340 nm - 400 nm) 281 µW/cm² = 2.81 W/m² vis. UVA ( 350 nm - 380 nm) 148 µW/cm² = 1.48 W/m² VIS Rep3 ( 350 nm - 600 nm) 1170 µW/cm² = 11.7 W/m² VIS Rep4 ( 350 nm - 700 nm) 1340 µW/cm² = 13.4 W/m² purple ( 380 nm - 420 nm) 224 µW/cm² = 2.24 W/m² VIS ( 380 nm - 780 nm) 1770 µW/cm² = 17.7 W/m² VIS2 ( 400 nm - 680 nm) 1080 µW/cm² = 10.8 W/m² PAR ( 400 nm - 700 nm) 1100 µW/cm² = 11 W/m² tmp ( 400 nm - 1100 nm) 2680 µW/cm² = 26.8 W/m² blue ( 420 nm - 490 nm) 402 µW/cm² = 4.02 W/m² green ( 490 nm - 575 nm) 329 µW/cm² = 3.29 W/m² yellow ( 575 nm - 585 nm) 28.9 µW/cm² = 0.289 W/m² orange ( 585 nm - 650 nm) 141 µW/cm² = 1.41 W/m² red ( 650 nm - 780 nm) 642 µW/cm² = 6.42 W/m² IRA ( 700 nm - 1400 nm) 1580 µW/cm² = 15.8 W/m² IR2 ( 720 nm - 1100 nm) 1520 µW/cm² = 15.2 W/m² IRB ( 1400 nm - 3000 nm) 0 µW/cm² = 0 W/m²
Actionspectra
Erythema 0.696 UV-Index Pyrimidine dimerization of DNA 8.78 µW/cm² Photoceratitis 1.01 µW/cm² Photoconjunctivitis 0.0153 µW/cm² DNA Damage 0.0509 Vitamin D3 2.79 µW/cm² Photosynthesis 821 µW/cm² Luminosity 2620 lx Human L-Cone 378 µW/cm² Human M-Cone 355 µW/cm² Human S-Cone 342 µW/cm² CIE X 341 µW/cm² CIE Y 361 µW/cm² CIE Z 618 µW/cm² PAR 5060000 mol photons Extinction preD3 25.8 e-3*m²/mol Extinction Tachysterol 95.4 e-3*m²/mol Exctincition PreD3 13500 m²/mol Extinction Lumisterol 2.13 m²/mol Exctincition Tachysterol 159000 m²/mol Extinction 7DHC 1.64 m²/mol L-Cone 299 µW/cm² M-Cone 453 µW/cm² S-Cone 601 µW/cm² U-Cone 512 µW/cm² UVR - ICNIRP 2004 0.462 Rel Biol Eff Melatonin Supression 487 µW/cm² Blue Light Hazard 404 µW/cm² (154 µW/cm² per 1000 lx) CIE 174:2006 PreVit D3 3.04 µW/cm² Lumen Reptil 3910 "pseudo-lx" Vitamin D3 Degradation 5.08 µW/cm² Actinic UV 0.462 µW/cm² (1.76 mW/klm) Exctincition Lumisterol 3640 m²/mol Exctincition 7DHC 2260 m²/mol Exctincition Toxisterols 3110 m²/mol
Broadbandmeters
Solarmeter 6.2 (UVB, pre 2010) 34.5 µW/cm² Solarmeter 6.5 (UV-Index, pre 2010) 0.86 Leybold UVB 22.9 µW/cm² Leybold UVA 204 µW/cm² Leybold UVC 0.000752 µW/cm² DeltaOhm UVB 79.9 µW/cm² DeltaOhm UVC 8.14 µW/cm² Vernier UVB 5.94 µW/cm² Vernier UVA 166 µW/cm² Gröbel UVA 237 µW/cm² Gröbel UVB 10.2 µW/cm² Gröbel UVC -0.00706 µW/cm² Luxmeter 2750 lx Solarmeter 6.4 (D3) 2.69 IU/min UVX-31 91.7 µW/cm² IL UVB 0.0161 µW/cm² IL UVA 237 µW/cm² Solarmeter 6.5 (UVI, post 2010) 0.745 UV-Index Solarmeter 6.2 (UVB, post 2010) 25.4 µW/cm² (Solarmeter Ratio = 34.1) Solarmeter AlGaN 6.5 UVI sensor 11.3 UV Index GenUV 7.1 UV-Index 0.732 UV-Index Solarmeter 10.0 (Global Power) (manuf.) 38.2 W/m² Solarmeter 4.0 (UVA) 3.64 mW/cm² LS122 (manuf.) 1.82 W/m² ISM400 (first guess) 39.9 W/m² LS122 (assumption) 2.44 W/m² ISM400_new 41.9 W/m² Solarmeter 10.0 (Global Power) (assumption) 37.4 W/m²