Solar altitude 85.4° San Bartolomé,
Gran Canaria (Latitude 27°55'N,
Longitude 15°31'W)
June 21st 2011 Local time 14:00h
Spectrum 512: 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:
Frances Baines
26/Oct/2014 ; updated:
Frances Baines
26/Oct/2014
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 ; 0.31 ) | ( 0.39 ; 0.4 ) | ( 0.26 ; 0.29 ; 0.3 ) |
| CCT | 6200 Kelvin | 5200 Kelvin | 5500 Kelvin |
| distance | 0.058 | 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) 59700 µW/cm² = 597 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) 59600 µW/cm² = 596 W/m² UVB (EU) ( 280 nm - 315 nm) 114 µW/cm² = 1.14 W/m² UVB (US) ( 280 nm - 320 nm) 204 µW/cm² = 2.04 W/m² UVA+B ( 280 nm - 380 nm) 3040 µW/cm² = 30.4 W/m² Solar UVB ( 290 nm - 315 nm) 114 µW/cm² = 1.14 W/m² UVA D3 regulating ( 315 nm - 335 nm) 574 µW/cm² = 5.74 W/m² UVA (EU) ( 315 nm - 380 nm) 2930 µW/cm² = 29.3 W/m² UVA2 (medical definition) ( 320 nm - 340 nm) 680 µW/cm² = 6.8 W/m² UVA (US) ( 320 nm - 380 nm) 2830 µW/cm² = 28.3 W/m² UVA1 (variant) ( 335 nm - 380 nm) 2350 µW/cm² = 23.5 W/m² UVA1 (medical) ( 340 nm - 400 nm) 3520 µW/cm² = 35.2 W/m² vis. UVA ( 350 nm - 380 nm) 1740 µW/cm² = 17.4 W/m² VIS Rep3 ( 350 nm - 600 nm) 31000 µW/cm² = 310 W/m² VIS Rep4 ( 350 nm - 700 nm) 43500 µW/cm² = 435 W/m² purple ( 380 nm - 420 nm) 3930 µW/cm² = 39.3 W/m² VIS ( 380 nm - 780 nm) 49100 µW/cm² = 491 W/m² PAR ( 400 nm - 700 nm) 40400 µW/cm² = 404 W/m² blue ( 420 nm - 490 nm) 11000 µW/cm² = 110 W/m² green ( 490 nm - 575 nm) 11000 µW/cm² = 110 W/m² yellow ( 575 nm - 585 nm) 1310 µW/cm² = 13.1 W/m² orange ( 585 nm - 650 nm) 8590 µW/cm² = 85.9 W/m² red ( 650 nm - 780 nm) 13200 µW/cm² = 132 W/m² IRA ( 700 nm - 1400 nm) 14900 µW/cm² = 149 W/m² IRB ( 1400 nm - 3000 nm) 0 µW/cm² = 0 W/m²
Actionspectra
Erythema 6.26 UV-Index Pyrimidine dimerization of DNA 78.2 µW/cm² Photoceratitis 8.9 µW/cm² Photoconjunctivitis 0.108 µW/cm² DNA Damage 0.346 Vitamin D3 26.3 µW/cm² Photosynthesis 29300 µW/cm² Luminosity 102000 lx Human L-Cone 15200 µW/cm² Human M-Cone 12500 µW/cm² Human S-Cone 8960 µW/cm² CIE X 14400 µW/cm² CIE Y 14000 µW/cm² CIE Z 16600 µW/cm² PAR 190000000 mol photons Extinction preD3 219 e-3*m²/mol Extinction Tachysterol 795 e-3*m²/mol Exctincition PreD3 114000 m²/mol Extinction Lumisterol 18 m²/mol Exctincition Tachysterol 1330000 m²/mol Extinction 7DHC 10.7 m²/mol L-Cone 13000 µW/cm² M-Cone 14400 µW/cm² S-Cone 14800 µW/cm² U-Cone 7800 µW/cm² UVR - ICNIRP 2004 4.02 Rel Biol Eff Melatonin Supression 13300 µW/cm² Blue Light Hazard 10300 µW/cm² (101 µW/cm² per 1000 lx) CIE 174:2006 PreVit D3 29.2 µW/cm² Lumen Reptil 115000 "pseudo-lx" Vitamin D3 Degradation 42.5 µW/cm² Actinic UV 4.01 µW/cm² (0.395 mW/klm) Exctincition Lumisterol 30900 m²/mol Exctincition 7DHC 15600 m²/mol Exctincition Toxisterols 26100 m²/mol
Broadbandmeters
Solarmeter 6.2 (UVB, pre 2010) 287 µW/cm² Solarmeter 6.5 (UV-Index, pre 2010) 7.99 Leybold UVB 191 µW/cm² Leybold UVA 2130 µW/cm² Leybold UVC 0.00166 µW/cm² DeltaOhm UVB 648 µW/cm² DeltaOhm UVC 65.1 µW/cm² Vernier UVB 55.4 µW/cm² Vernier UVA 1550 µW/cm² Gröbel UVA 2380 µW/cm² Gröbel UVB 89 µW/cm² Gröbel UVC -0.0536 µW/cm² Solarmeter 6.4 (D3) 25 IU/min UVX-31 770 µW/cm² IL UVB 0.135 µW/cm² IL UVA 2500 µW/cm² Solarmeter 6.5 (UVI, post 2010) 6.92 UV-Index Solarmeter 6.2 (UVB, post 2010) 205 µW/cm² (Solarmeter Ratio = 29.6) Solarmeter AlGaN 6.5 UVI sensor 100 UV Index GenUV 7.1 UV-Index 6.45 UV-Index Solarmeter 10.0 (Global Power) 686 W/m² Solarmeter 4.0 (UVA) 42.2 mW/cm² LS122 8.19 W/m² ISM400 604 W/m²