Spectrum 252: BEL18 Edit
DeleteMeasurement
Brand |
other other |
---|---|
Lamp Product |
Chinese Prototype 5.0 T8 18W |
Lamp ID |
BEL18 (12/2008) |
Spectrometer | USB2000+ |
Ballast | - no ballast or default/unknown ballast - |
Reflector | |
Distance | 10 cm |
Age | 105 hours |
Originator (measurement) | Frances Baines |
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 ; 0.26 ) | ( 0.25 ; 0.41 ) | ( 0.15 ; 0.21 ; 0.35 ) |
CCT | 20000 Kelvin | 10000 Kelvin | 12000 Kelvin |
distance | 0.077 | 0.066 | |
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
total ( 0 nm - 0 nm) 645 µW/cm² = 6.45 W/m² UVC ( 0 nm - 280 nm) 0.562 µW/cm² = 0.00562 W/m² non-terrestrial ( 0 nm - 290 nm) 0.929 µW/cm² = 0.00929 W/m² total2 ( 250 nm - 880 nm) 645 µW/cm² = 6.45 W/m² UVB (EU) ( 280 nm - 315 nm) 25.4 µW/cm² = 0.254 W/m² UVB (US) ( 280 nm - 320 nm) 37.3 µW/cm² = 0.373 W/m² UVA+B ( 280 nm - 380 nm) 233 µW/cm² = 2.33 W/m² Solar UVB ( 290 nm - 315 nm) 25 µW/cm² = 0.25 W/m² UVA D3 regulating ( 315 nm - 335 nm) 61.6 µW/cm² = 0.616 W/m² UVA (EU) ( 315 nm - 380 nm) 208 µW/cm² = 2.08 W/m² UVA2 (medical definition) ( 320 nm - 340 nm) 70.5 µW/cm² = 0.705 W/m² UVA (US) ( 320 nm - 380 nm) 196 µW/cm² = 1.96 W/m² UVA1 (variant) ( 335 nm - 380 nm) 146 µW/cm² = 1.46 W/m² UVA1 (medical) ( 340 nm - 400 nm) 147 µW/cm² = 1.47 W/m² vis. UVA ( 350 nm - 380 nm) 86.5 µW/cm² = 0.865 W/m² VIS Rep3 ( 350 nm - 600 nm) 417 µW/cm² = 4.17 W/m² VIS Rep4 ( 350 nm - 700 nm) 473 µW/cm² = 4.73 W/m² purple ( 380 nm - 420 nm) 57.8 µW/cm² = 0.578 W/m² VIS ( 380 nm - 780 nm) 402 µW/cm² = 4.02 W/m² VIS2 ( 400 nm - 680 nm) 357 µW/cm² = 3.57 W/m² PAR ( 400 nm - 700 nm) 365 µW/cm² = 3.65 W/m² tmp ( 400 nm - 1100 nm) 390 µW/cm² = 3.9 W/m² blue ( 420 nm - 490 nm) 143 µW/cm² = 1.43 W/m² green ( 490 nm - 575 nm) 105 µW/cm² = 1.05 W/m² yellow ( 575 nm - 585 nm) 12.7 µW/cm² = 0.127 W/m² orange ( 585 nm - 650 nm) 44.6 µW/cm² = 0.446 W/m² red ( 650 nm - 780 nm) 38.2 µW/cm² = 0.382 W/m² IRA ( 700 nm - 1400 nm) 25.4 µW/cm² = 0.254 W/m² IR2 ( 720 nm - 1100 nm) 20.1 µW/cm² = 0.201 W/m² IRB ( 1400 nm - 3000 nm) 0 µW/cm² = 0 W/m²
Erythema 2.57 UV-Index Pyrimidine dimerization of DNA 15.5 µW/cm² Photoceratitis 3.69 µW/cm² Photoconjunctivitis 0.625 µW/cm² DNA Damage 0.975 Vitamin D3 8.73 µW/cm² Photosynthesis 268 µW/cm² Luminosity 870 lx Human L-Cone 125 µW/cm² Human M-Cone 117 µW/cm² Human S-Cone 123 µW/cm² CIE X 118 µW/cm² CIE Y 120 µW/cm² CIE Z 225 µW/cm² PAR 1720000 mol photons Extinction preD3 52.6 e-3*m²/mol Extinction Tachysterol 182 e-3*m²/mol Exctincition PreD3 29200 m²/mol Extinction Lumisterol 17.1 m²/mol Exctincition Tachysterol 261000 m²/mol Extinction 7DHC 19.6 m²/mol L-Cone 99.3 µW/cm² M-Cone 136 µW/cm² S-Cone 223 µW/cm² U-Cone 187 µW/cm² UVR - ICNIRP 2004 2.76 Rel Biol Eff Melatonin Supression 160 µW/cm² Blue Light Hazard 141 µW/cm² (162 µW/cm² per 1000 lx) CIE 174:2006 PreVit D3 9.45 µW/cm² Lumen Reptil 1310 "pseudo-lx" Vitamin D3 Degradation 8.13 µW/cm² Actinic UV 2.73 µW/cm² (31.4 mW/klm) Exctincition Lumisterol 21100 m²/mol Exctincition 7DHC 23000 m²/mol Exctincition Toxisterols 6030 m²/mol
Solarmeter 6.2 (UVB, pre 2010) 46.6 µW/cm² Solarmeter 6.5 (UV-Index, pre 2010) 2.58 Leybold UVB 32.8 µW/cm² Leybold UVA 146 µW/cm² Leybold UVC 0.422 µW/cm² DeltaOhm UVB 80.7 µW/cm² DeltaOhm UVC 10.1 µW/cm² Vernier UVB 12.7 µW/cm² Vernier UVA 135 µW/cm² Gröbel UVA 177 µW/cm² Gröbel UVB 18.5 µW/cm² Gröbel UVC 0.445 µW/cm² Luxmeter 912 lx Solarmeter 6.4 (D3) 8.06 IU/min UVX-31 91.6 µW/cm² IL UVB 0.021 µW/cm² IL UVA 165 µW/cm² Solarmeter 6.5 (UVI, post 2010) 1.96 UV-Index Solarmeter 6.2 (UVB, post 2010) 30.1 µW/cm² (Solarmeter Ratio = 15.3) Solarmeter AlGaN 6.5 UVI sensor 21.5 UV Index GenUV 7.1 UV-Index 1.21 UV-Index Solarmeter 10.0 (Global Power) (manuf.) 4.89 W/m² Solarmeter 4.0 (UVA) 2.22 mW/cm² LS122 (manuf.) 0.00738 W/m² ISM400 (first guess) 2.7 W/m² LS122 (assumption) 0.112 W/m² ISM400_new 2.17 W/m² Solarmeter 10.0 (Global Power) (assumption) 4.04 W/m²