2010-05-23; 14:07 (solar altitude 56.8)
blue sky in shade of house
Spectrum 434: 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 | ( 0.25 ; 0.26 ) | ( 0.28 ; 0.39 ) | ( 0.15 ; 0.24 ; 0.33 ) |
| CCT | 20000 Kelvin | 8400 Kelvin | 10000 Kelvin |
| distance | 0.051 | 0.055 | |
| 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) 4110 µW/cm² = 41.1 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) 4100 µW/cm² = 41 W/m² UVB (EU) ( 280 nm - 315 nm) 24.3 µW/cm² = 0.243 W/m² UVB (US) ( 280 nm - 320 nm) 46.8 µW/cm² = 0.468 W/m² UVA+B ( 280 nm - 380 nm) 584 µW/cm² = 5.84 W/m² Solar UVB ( 290 nm - 315 nm) 24.3 µW/cm² = 0.243 W/m² UVA D3 regulating ( 315 nm - 335 nm) 142 µW/cm² = 1.42 W/m² UVA (EU) ( 315 nm - 380 nm) 559 µW/cm² = 5.59 W/m² UVA2 (medical definition) ( 320 nm - 340 nm) 164 µW/cm² = 1.64 W/m² UVA (US) ( 320 nm - 380 nm) 537 µW/cm² = 5.37 W/m² UVA1 (variant) ( 335 nm - 380 nm) 418 µW/cm² = 4.18 W/m² UVA1 (medical) ( 340 nm - 400 nm) 543 µW/cm² = 5.43 W/m² vis. UVA ( 350 nm - 380 nm) 287 µW/cm² = 2.87 W/m² VIS Rep3 ( 350 nm - 600 nm) 2180 µW/cm² = 21.8 W/m² VIS Rep4 ( 350 nm - 700 nm) 2500 µW/cm² = 25 W/m² purple ( 380 nm - 420 nm) 431 µW/cm² = 4.31 W/m² VIS ( 380 nm - 780 nm) 2740 µW/cm² = 27.4 W/m² VIS2 ( 400 nm - 680 nm) 1990 µW/cm² = 19.9 W/m² PAR ( 400 nm - 700 nm) 2040 µW/cm² = 20.4 W/m² tmp ( 400 nm - 1100 nm) 3350 µW/cm² = 33.5 W/m² blue ( 420 nm - 490 nm) 770 µW/cm² = 7.7 W/m² green ( 490 nm - 575 nm) 575 µW/cm² = 5.75 W/m² yellow ( 575 nm - 585 nm) 51.1 µW/cm² = 0.511 W/m² orange ( 585 nm - 650 nm) 254 µW/cm² = 2.54 W/m² red ( 650 nm - 780 nm) 657 µW/cm² = 6.57 W/m² IRA ( 700 nm - 1400 nm) 1310 µW/cm² = 13.1 W/m² IR2 ( 720 nm - 1100 nm) 1240 µW/cm² = 12.4 W/m² IRB ( 1400 nm - 3000 nm) 0 µW/cm² = 0 W/m²
Actionspectra
Erythema 1.22 UV-Index Pyrimidine dimerization of DNA 16.6 µW/cm² Photoceratitis 1.75 µW/cm² Photoconjunctivitis 0.0194 µW/cm² DNA Damage 0.0623 Vitamin D3 5 µW/cm² Photosynthesis 1520 µW/cm² Luminosity 4620 lx Human L-Cone 665 µW/cm² Human M-Cone 625 µW/cm² Human S-Cone 656 µW/cm² CIE X 618 µW/cm² CIE Y 633 µW/cm² CIE Z 1180 µW/cm² PAR 9320000 mol photons Extinction preD3 48.5 e-3*m²/mol Extinction Tachysterol 179 e-3*m²/mol Exctincition PreD3 25300 m²/mol Extinction Lumisterol 3.15 m²/mol Exctincition Tachysterol 300000 m²/mol Extinction 7DHC 1.82 m²/mol L-Cone 524 µW/cm² M-Cone 834 µW/cm² S-Cone 1150 µW/cm² U-Cone 988 µW/cm² UVR - ICNIRP 2004 0.732 Rel Biol Eff Melatonin Supression 927 µW/cm² Blue Light Hazard 774 µW/cm² (168 µW/cm² per 1000 lx) CIE 174:2006 PreVit D3 5.47 µW/cm² Lumen Reptil 7280 "pseudo-lx" Vitamin D3 Degradation 9.64 µW/cm² Actinic UV 0.734 µW/cm² (1.59 mW/klm) Exctincition Lumisterol 5900 m²/mol Exctincition 7DHC 2770 m²/mol Exctincition Toxisterols 5960 m²/mol
Broadbandmeters
Solarmeter 6.2 (UVB, pre 2010) 65.9 µW/cm² Solarmeter 6.5 (UV-Index, pre 2010) 1.55 Leybold UVB 43.7 µW/cm² Leybold UVA 396 µW/cm² Leybold UVC 0.000396 µW/cm² DeltaOhm UVB 155 µW/cm² DeltaOhm UVC 15.6 µW/cm² Vernier UVB 11.1 µW/cm² Vernier UVA 322 µW/cm² Gröbel UVA 458 µW/cm² Gröbel UVB 19.3 µW/cm² Gröbel UVC -0.0136 µW/cm² Luxmeter 4830 lx Solarmeter 6.4 (D3) 4.84 IU/min UVX-31 177 µW/cm² IL UVB 0.0309 µW/cm² IL UVA 459 µW/cm² Solarmeter 6.5 (UVI, post 2010) 1.37 UV-Index Solarmeter 6.2 (UVB, post 2010) 48.8 µW/cm² (Solarmeter Ratio = 35.7) Solarmeter AlGaN 6.5 UVI sensor 21.4 UV Index GenUV 7.1 UV-Index 1.39 UV-Index Solarmeter 10.0 (Global Power) (manuf.) 44 W/m² Solarmeter 4.0 (UVA) 7.04 mW/cm² LS122 (manuf.) 1.42 W/m² ISM400 (first guess) 39.4 W/m² LS122 (assumption) 2.22 W/m² ISM400_new 39.3 W/m² Solarmeter 10.0 (Global Power) (assumption) 41.4 W/m²