TrueLight T8 tube used for 1 year at Slimbridge WWT UK
Spectrum 537: BWWT1 Edit
DeleteMeasurement
| Brand |
other other |
|---|---|
| Lamp Product |
True Light |
| Lamp ID |
BWWT1 (03/2016) TrueLight 58W T8 fluorescent tube - 1 year of use |
| Spectrometer | USB2000+ (2) |
| Ballast | - no ballast or default/unknown ballast - |
| Reflector | |
| Distance | 86 cm |
| Age | 4,000 hours |
| Originator (measurement) | Frances Baines |
Database entry created:
Frances Baines
17/Apr/2017 ; updated:
Frances Baines
17/Apr/2017
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 ; 0.33 ) | ( 0.49 ; 0.39 ) | ( 0.28 ; 0.35 ; 0.28 ) |
| CCT | 6500 Kelvin | 3800 Kelvin | 4900 Kelvin |
| distance | 0.06 | 0.084 | |
| 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) 110 µW/cm² = 1.1 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) 110 µW/cm² = 1.1 W/m² UVB (EU) ( 280 nm - 315 nm) 0.15 µW/cm² = 0.0015 W/m² UVB (US) ( 280 nm - 320 nm) 0.233 µW/cm² = 0.00233 W/m² UVA+B ( 280 nm - 380 nm) 5.64 µW/cm² = 0.0564 W/m² Solar UVB ( 290 nm - 315 nm) 0.15 µW/cm² = 0.0015 W/m² UVA D3 regulating ( 315 nm - 335 nm) 0.768 µW/cm² = 0.00768 W/m² UVA (EU) ( 315 nm - 380 nm) 5.49 µW/cm² = 0.0549 W/m² UVA2 (medical definition) ( 320 nm - 340 nm) 1.06 µW/cm² = 0.0106 W/m² UVA (US) ( 320 nm - 380 nm) 5.41 µW/cm² = 0.0541 W/m² UVA1 (variant) ( 335 nm - 380 nm) 4.72 µW/cm² = 0.0472 W/m² UVA1 (medical) ( 340 nm - 400 nm) 5.79 µW/cm² = 0.0579 W/m² vis. UVA ( 350 nm - 380 nm) 3.48 µW/cm² = 0.0348 W/m² VIS Rep3 ( 350 nm - 600 nm) 78.3 µW/cm² = 0.783 W/m² VIS Rep4 ( 350 nm - 700 nm) 102 µW/cm² = 1.02 W/m² purple ( 380 nm - 420 nm) 4.09 µW/cm² = 0.0409 W/m² VIS ( 380 nm - 780 nm) 104 µW/cm² = 1.04 W/m² PAR ( 400 nm - 700 nm) 97.5 µW/cm² = 0.975 W/m² blue ( 420 nm - 490 nm) 30.1 µW/cm² = 0.301 W/m² green ( 490 nm - 575 nm) 33.4 µW/cm² = 0.334 W/m² yellow ( 575 nm - 585 nm) 3.03 µW/cm² = 0.0303 W/m² orange ( 585 nm - 650 nm) 23 µW/cm² = 0.23 W/m² red ( 650 nm - 780 nm) 10.7 µW/cm² = 0.107 W/m² IRA ( 700 nm - 1400 nm) 5.49 µW/cm² = 0.0549 W/m² IRB ( 1400 nm - 3000 nm) 0 µW/cm² = 0 W/m²
Actionspectra
Erythema 0.005 UV-Index Pyrimidine dimerization of DNA 0.072 µW/cm² Photoceratitis 0.00763 µW/cm² Photoconjunctivitis 1.28E-5 µW/cm² DNA Damage 0.000112 Vitamin D3 0.0165 µW/cm² Photosynthesis 67.6 µW/cm² Luminosity 293 lx Human L-Cone 43.4 µW/cm² Human M-Cone 37.1 µW/cm² Human S-Cone 22.7 µW/cm² CIE X 38.5 µW/cm² CIE Y 40.4 µW/cm² CIE Z 43.9 µW/cm² PAR 448000 mol photons Extinction preD3 0.226 e-3*m²/mol Extinction Tachysterol 0.841 e-3*m²/mol Exctincition PreD3 132 m²/mol Extinction Lumisterol 0.00576 m²/mol Exctincition Tachysterol 1620 m²/mol Extinction 7DHC 0.00134 m²/mol L-Cone 35.8 µW/cm² M-Cone 44.5 µW/cm² S-Cone 34.9 µW/cm² U-Cone 11 µW/cm² UVR - ICNIRP 2004 0.00258 Rel Biol Eff Melatonin Supression 35.1 µW/cm² Blue Light Hazard 24.6 µW/cm² (84.2 µW/cm² per 1000 lx) CIE 174:2006 PreVit D3 0.0159 µW/cm² Lumen Reptil 297 "pseudo-lx" Vitamin D3 Degradation 0.0468 µW/cm² Actinic UV 0.00256 µW/cm² (0.0874 mW/klm) Exctincition Lumisterol 17.9 m²/mol Exctincition 7DHC 5.4 m²/mol Exctincition Toxisterols 36.5 m²/mol
Broadbandmeters
Solarmeter 6.2 (UVB, pre 2010) 0.337 µW/cm² Solarmeter 6.5 (UV-Index, pre 2010) 0.00525 Leybold UVB 0.222 µW/cm² Leybold UVA 4.15 µW/cm² Leybold UVC 0 µW/cm² DeltaOhm UVB 0.913 µW/cm² DeltaOhm UVC 0.0779 µW/cm² Vernier UVB 0.0433 µW/cm² Vernier UVA 2.78 µW/cm² Gröbel UVA 4.64 µW/cm² Gröbel UVB 0.0983 µW/cm² Gröbel UVC -8.64E-5 µW/cm² Solarmeter 6.4 (D3) 0.0164 IU/min UVX-31 1.18 µW/cm² IL UVB 0.000176 µW/cm² IL UVA 4.85 µW/cm² Solarmeter 6.5 (UVI, post 2010) 0.00511 UV-Index Solarmeter 6.2 (UVB, post 2010) 0.246 µW/cm² (Solarmeter Ratio = 48.2) Solarmeter AlGaN 6.5 UVI sensor 0.109 UV Index GenUV 7.1 UV-Index 0.0074 UV-Index Solarmeter 10.0 (Global Power) 1.11 W/m² Solarmeter 4.0 (UVA) 0.0729 mW/cm² LS122 0 W/m² ISM400 0.766 W/m²