Spectrum 327: BRO2 Edit
DeleteMeasurement
| Brand |
Reptile One http://www.reptileone.com. |
|---|---|
| Lamp Product |
UVB 5.0 T8 18W |
| Lamp ID |
BRO2 (09/2009) |
| Spectrometer | USB2000+ (2) |
| Ballast | - no ballast or default/unknown ballast - |
| Reflector | |
| Distance | 10 cm |
| Age | 105 hours |
| Originator (measurement) | Frances Baines |
Database entry created:
Sarina Wunderlich
3/Jul/2010 ; updated:
Sarina Wunderlich
27/Feb/2011
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 | ( 0.31 ; 0.29 ) | ( 0.29 ; 0.43 ) | ( 0.22 ; 0.22 ; 0.33 ) |
| CCT | 7400 Kelvin | 7900 Kelvin | 7100 Kelvin |
| distance | 0.09 | 0.07 | |
| 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) 817 µW/cm² = 8.17 W/m² UVC ( 0 nm - 280 nm) 0.706 µW/cm² = 0.00706 W/m² non-terrestrial ( 0 nm - 290 nm) 1.26 µW/cm² = 0.0126 W/m² total2 ( 250 nm - 880 nm) 817 µW/cm² = 8.17 W/m² UVB (EU) ( 280 nm - 315 nm) 25.2 µW/cm² = 0.252 W/m² UVB (US) ( 280 nm - 320 nm) 33.5 µW/cm² = 0.335 W/m² UVA+B ( 280 nm - 380 nm) 178 µW/cm² = 1.78 W/m² Solar UVB ( 290 nm - 315 nm) 24.7 µW/cm² = 0.247 W/m² UVA D3 regulating ( 315 nm - 335 nm) 42.8 µW/cm² = 0.428 W/m² UVA (EU) ( 315 nm - 380 nm) 153 µW/cm² = 1.53 W/m² UVA2 (medical definition) ( 320 nm - 340 nm) 48.6 µW/cm² = 0.486 W/m² UVA (US) ( 320 nm - 380 nm) 144 µW/cm² = 1.44 W/m² UVA1 (variant) ( 335 nm - 380 nm) 110 µW/cm² = 1.1 W/m² UVA1 (medical) ( 340 nm - 400 nm) 117 µW/cm² = 1.17 W/m² vis. UVA ( 350 nm - 380 nm) 69.9 µW/cm² = 0.699 W/m² VIS Rep3 ( 350 nm - 600 nm) 513 µW/cm² = 5.13 W/m² VIS Rep4 ( 350 nm - 700 nm) 661 µW/cm² = 6.61 W/m² purple ( 380 nm - 420 nm) 63.6 µW/cm² = 0.636 W/m² VIS ( 380 nm - 780 nm) 627 µW/cm² = 6.27 W/m² VIS2 ( 400 nm - 680 nm) 550 µW/cm² = 5.5 W/m² PAR ( 400 nm - 700 nm) 570 µW/cm² = 5.7 W/m² tmp ( 400 nm - 1100 nm) 617 µW/cm² = 6.17 W/m² blue ( 420 nm - 490 nm) 176 µW/cm² = 1.76 W/m² green ( 490 nm - 575 nm) 156 µW/cm² = 1.56 W/m² yellow ( 575 nm - 585 nm) 22.2 µW/cm² = 0.222 W/m² orange ( 585 nm - 650 nm) 113 µW/cm² = 1.13 W/m² red ( 650 nm - 780 nm) 97 µW/cm² = 0.97 W/m² IRA ( 700 nm - 1400 nm) 47.2 µW/cm² = 0.472 W/m² IR2 ( 720 nm - 1100 nm) 33.3 µW/cm² = 0.333 W/m² IRB ( 1400 nm - 3000 nm) 0 µW/cm² = 0 W/m²
Actionspectra
Erythema 2.37 UV-Index Pyrimidine dimerization of DNA 13.2 µW/cm² Photoceratitis 3.46 µW/cm² Photoconjunctivitis 0.753 µW/cm² DNA Damage 1.14 Vitamin D3 7.54 µW/cm² Photosynthesis 410 µW/cm² Luminosity 1450 lx Human L-Cone 216 µW/cm² Human M-Cone 181 µW/cm² Human S-Cone 151 µW/cm² CIE X 210 µW/cm² CIE Y 200 µW/cm² CIE Z 276 µW/cm² PAR 2730000 mol photons Extinction preD3 48.5 e-3*m²/mol Extinction Tachysterol 165 e-3*m²/mol Exctincition PreD3 27700 m²/mol Extinction Lumisterol 17.5 m²/mol Exctincition Tachysterol 229000 m²/mol Extinction 7DHC 20.6 m²/mol L-Cone 183 µW/cm² M-Cone 182 µW/cm² S-Cone 272 µW/cm² U-Cone 181 µW/cm² UVR - ICNIRP 2004 2.69 Rel Biol Eff Melatonin Supression 199 µW/cm² Blue Light Hazard 171 µW/cm² (118 µW/cm² per 1000 lx) CIE 174:2006 PreVit D3 8.03 µW/cm² Lumen Reptil 1770 "pseudo-lx" Vitamin D3 Degradation 7.26 µW/cm² Actinic UV 2.66 µW/cm² (18.4 mW/klm) Exctincition Lumisterol 21200 m²/mol Exctincition 7DHC 23900 m²/mol Exctincition Toxisterols 6030 m²/mol
Broadbandmeters
Solarmeter 6.2 (UVB, pre 2010) 40.7 µW/cm² Solarmeter 6.5 (UV-Index, pre 2010) 2.26 Leybold UVB 28.8 µW/cm² Leybold UVA 107 µW/cm² Leybold UVC 0.507 µW/cm² DeltaOhm UVB 62.8 µW/cm² DeltaOhm UVC 8.37 µW/cm² Vernier UVB 11.3 µW/cm² Vernier UVA 97.6 µW/cm² Gröbel UVA 131 µW/cm² Gröbel UVB 16.4 µW/cm² Gröbel UVC 0.546 µW/cm² Luxmeter 1470 lx Solarmeter 6.4 (D3) 7.06 IU/min UVX-31 70.9 µW/cm² IL UVB 0.0176 µW/cm² IL UVA 123 µW/cm² Solarmeter 6.5 (UVI, post 2010) 1.7 UV-Index Solarmeter 6.2 (UVB, post 2010) 25.3 µW/cm² (Solarmeter Ratio = 14.9) Solarmeter AlGaN 6.5 UVI sensor 19.7 UV Index GenUV 7.1 UV-Index 1.1 UV-Index Solarmeter 10.0 (Global Power) (manuf.) 7.34 W/m² Solarmeter 4.0 (UVA) 1.72 mW/cm² LS122 (manuf.) 0.00802 W/m² ISM400 (first guess) 4.87 W/m² LS122 (assumption) 0.23 W/m² ISM400_new 4.07 W/m² Solarmeter 10.0 (Global Power) (assumption) 6.62 W/m²