Spectrum 582: BRSU1 EditDelete
French brand, originally for aqaristics https://www.aquariumsystems.fr/
New Dawn UVI Flood 13W
60-LED UV-emitting LED bar. Specifications: 30 x UVB LED, 2 x UVA LED, 28 x 6500K LED, 13 watts, 120-deg beam angle. 20cm: UVI 5.1; 20-30cm: UVI 3.3 - 5.1; 30-50cm: UVI 3.3 - 1.3; 50-80cm: UVI 0.5 - 1.3
|Ballast||- no ballast or default/unknown ballast -|
|Originator (measurement)||Frances Baines|
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|
|Colour Coordinate||( 0.3 ; 0.29 )||( 0.36 ; 0.55 )||( 0.27 ; 0.26 ; 0.4 )|
|CCT||7900 Kelvin||5700 Kelvin||5500 Kelvin|
|colour space||3-D-graph not implemented yet|
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.
The equilibrium of the photoproducts depends on the actual UV spectrum in the range 250 nm - 340 nm. With knowledge of the conversion probabilities and absorption spectra of 7DHC, PreD3, Tachysterol, and Lumisterol it is possible to calculate the ratio of photoproducts in equilibrium. This is based on scientific literature , however the constants that are used for the calculation are not well calibrated with experiments. It is therefore not a solid method, but I consider it useful as a first guess how natural a UV spectrum is.
Caveat: This evaluation is extremely sensitive to the qualitiy of the spectral measurement in the range 220 nm - 340 nm. High quality spectrometers and good background calibration is needed to get the noise below 300 nm low enough for this evaluation. Please check at least the UV graph above for noise.
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.
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
UVA (EU) ( 315 nm - 400 nm) 121 µW/cm² = 1.21 W/m² UVA (US) ( 320 nm - 400 nm) 107 µW/cm² = 1.07 W/m² UVB (EU) ( 280 nm - 315 nm) 96.4 µW/cm² = 0.964 W/m² UVB (US) ( 280 nm - 320 nm) 110 µW/cm² = 1.1 W/m² UVC ( 0 nm - 280 nm) 0.227 µW/cm² = 0.00227 W/m² vis. UVA ( 350 nm - 380 nm) 5.04 µW/cm² = 0.0504 W/m² purple ( 380 nm - 420 nm) 251 µW/cm² = 2.51 W/m² blue ( 420 nm - 490 nm) 1490 µW/cm² = 14.9 W/m² green ( 490 nm - 575 nm) 1400 µW/cm² = 14 W/m² yellow ( 575 nm - 585 nm) 178 µW/cm² = 1.78 W/m² orange ( 585 nm - 650 nm) 906 µW/cm² = 9.06 W/m² red ( 650 nm - 780 nm) 252 µW/cm² = 2.52 W/m² VIS ( 380 nm - 780 nm) 4480 µW/cm² = 44.8 W/m² PAR ( 400 nm - 700 nm) 4350 µW/cm² = 43.5 W/m² total ( 0 nm - 0 nm) 4620 µW/cm² = 46.2 W/m² UVA1 ( 315 nm - 350 nm) 34.6 µW/cm² = 0.346 W/m² VIS Rep3 ( 350 nm - 600 nm) 3590 µW/cm² = 35.9 W/m² VIS Rep4 ( 350 nm - 700 nm) 4440 µW/cm² = 44.4 W/m² IRA ( 700 nm - 1400 nm) 49.1 µW/cm² = 0.491 W/m² IRB ( 1400 nm - 3000 nm) 0 µW/cm² = 0 W/m²
Erythema 10.6 UV-Index Pyrimidine dimerization of DNA 64.3 µW/cm² Photoceratitis 15.8 µW/cm² Photoconjunctivitis 0.711 µW/cm² DNA Damage 1.99 Vitamin D3 43 µW/cm² Photosynthesis 3060 µW/cm² Luminosity 12700 lx Human L-Cone 1890 µW/cm² Human M-Cone 1600 µW/cm² Human S-Cone 1330 µW/cm² CIE X 1820 µW/cm² CIE Y 1760 µW/cm² CIE Z 2470 µW/cm² PAR 19700000 mol photons Extinction preD3 0.176 m²/mol Extinction Tachysterol 0.601 m²/mol Extinction Lumisterol 0.0618 m²/mol Extinction 7DHC 0.0655 m²/mol L-Cone 1570 µW/cm² M-Cone 1540 µW/cm² S-Cone 2340 µW/cm² U-Cone 375 µW/cm² UVR - ICNIRP 2004 10.7 Rel Biol Eff Melatonin Supression 1650 µW/cm² Blue Light Hazard 1430 µW/cm² (112 µW/cm² per 1000 lx) CIE 174:2006 PreVit D3 48.1 µW/cm² Lumen Reptil 13300 "pseudo-lx" Vitamin D3 Degradation 25.9 µW/cm²
Solarmeter 6.2 (UVB, pre 2010) 122 µW/cm² Solarmeter 6.5 (UV-Index, pre 2010) 12.2 Leybold UVB 97.8 µW/cm² Leybold UVA 19.6 µW/cm² Leybold UVC 0.125 µW/cm² DeltaOhm UVB 107 µW/cm² DeltaOhm UVC 19.5 µW/cm² Vernier UVB 61.6 µW/cm² Vernier UVA 46.8 µW/cm² Gröbel UVA 38 µW/cm² Gröbel UVB 68.7 µW/cm² Gröbel UVC 0.155 µW/cm² Solarmeter 6.4 (D3) 38.2 IU/min UVX-31 119 µW/cm² IL UVB 0.0527 µW/cm² IL UVA 24.4 µW/cm² Solarmeter 6.5 (UVI, post 2010) 9.14 UV-Index Solarmeter 6.2 (UVB, post 2010) 63.5 µW/cm² (Solarmeter Ratio = 6.95) Solarmeter AlGaN 6.5 UVI sensor 85.8 UV Index GenUV 7.1 UV-Index 4.14 UV-Index Solarmeter 10.0 (Global Power) 44.7 W/m² Solarmeter 4.0 (UVA) 0.991 mW/cm²