Reptile Lamp Database

Spectrum 6: BA6 Edit
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Full Spectrum

Measurement

Brand Arcadia
UK company https://www.arcadiareptile.com/
Lamp Product D3 Reptile Lamp 18W
6% UVB, 30% UVA, 6500K
Lamp ID BA6 (10/2007)
Spectrometer USB 2000
Ballast - no ballast or default/unknown ballast -
Reflector
Distance 10 cm
Age 8,000 hours
Originator (measurement) Frances Baines
Database entry created: Sarina Wunderlich 9/Nov/2009 ; updated: Sarina Wunderlich 9/Oct/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.

WARNING: The measurement range (350 - 800 nm) is not sufficient for this evaluation! Data is only available in the range 250.17 - 780.01 nm. Results are shown anyway but should be ignored by anyone except experts.

Spectrum in the visible wavelength range

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, 338451, 511513 ), indicated by crosses, coloured in the appriximate colour perceived by a human.

Human (CIE) 3 cone reptile 4 cone reptile
Cone Excitation
Colour Coordinate ( 0.3 ; 0.31 ) ( 0.38 ; 0.46 ) ( 0.25 ; 0.29 ; 0.34 )
CCT 7900 Kelvin 5300 Kelvin 5700 Kelvin
distance 0.12 0.092
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.

Spectrum in the vitamin D3 active wavelength range

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 [1066], 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.

Simulation of the development of the Vitamin D3 photoproducts Simulation of the development of the Vitamin D3 photoproducts

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
then any Solarmeter 6.2 reading multiplied with 0.7 (0.7=13.8/19.6) is an estimate of UVB irradiance for this specific lamp. If you do so, always make sure, that the calculated (effective) irradiance is valid. The calculated value is not valid, if the lamp's spectrum is not measured in the relevant range.

Ranges
UVA (EU) ( 315 nm - 400 nm) 123 µW/cm² = 1.23 W/m²
UVA (US) ( 320 nm - 400 nm) 112 µW/cm² = 1.12 W/m²
UVB (EU) ( 280 nm - 315 nm) 13.4 µW/cm² = 0.134 W/m²
UVB (US) ( 280 nm - 320 nm) 24.6 µW/cm² = 0.246 W/m²
UVC ( 0 nm - 280 nm) 1.09 µW/cm² = 0.0109 W/m²
vis. UVA ( 350 nm - 380 nm) 25.3 µW/cm² = 0.253 W/m²
purple ( 380 nm - 420 nm) 23.5 µW/cm² = 0.235 W/m²
blue ( 420 nm - 490 nm) 115 µW/cm² = 1.15 W/m²
green ( 490 nm - 575 nm) 114 µW/cm² = 1.14 W/m²
yellow ( 575 nm - 585 nm) 14.9 µW/cm² = 0.149 W/m²
orange ( 585 nm - 650 nm) 66.6 µW/cm² = 0.666 W/m²
red ( 650 nm - 780 nm) 62.1 µW/cm² = 0.621 W/m²
VIS ( 380 nm - 780 nm) 397 µW/cm² = 3.97 W/m²
PAR ( 400 nm - 700 nm) 374 µW/cm² = 3.74 W/m²
total ( 0 nm - 0 nm) 531 µW/cm² = 5.31 W/m²
UVA1 ( 315 nm - 350 nm) 94.6 µW/cm² = 0.946 W/m²
VIS Rep3 ( 350 nm - 600 nm) 308 µW/cm² = 3.08 W/m²
VIS Rep4 ( 350 nm - 700 nm) 402 µW/cm² = 4.02 W/m²
IRA ( 700 nm - 1400 nm) 19.5 µW/cm² = 0.195 W/m²
IRB ( 1400 nm - 3000 nm) 0 µW/cm² = 0 W/m²
Actionspectra
Erythema 1.27 UV-Index
Pyrimidine dimerization of DNA 8.52 µW/cm²
Photoceratitis 1.65 µW/cm²
Photoconjunctivitis 1.02 µW/cm²
DNA Damage 1.19
Vitamin D3 3.41 µW/cm²
Photosynthesis 266 µW/cm²
Luminosity 985 lx
Human L-Cone 145 µW/cm²
Human M-Cone 127 µW/cm²
Human S-Cone 95 µW/cm²
CIE X 132 µW/cm²
CIE Y 137 µW/cm²
CIE Z 178 µW/cm²
PAR 1790000 mol photons
Extinction preD3 0.0353 m²/mol
Extinction Tachysterol 0.112 m²/mol
Extinction Lumisterol 0.0116 m²/mol
Extinction 7DHC 0.0128 m²/mol
L-Cone 120 µW/cm²
M-Cone 137 µW/cm²
S-Cone 163 µW/cm²
U-Cone 55.1 µW/cm²
UVR - ICNIRP 2004 1.53 Rel Biol Eff
Melatonin Supression 131 µW/cm²
Blue Light Hazard 106 µW/cm² (108 µW/cm² per 1000 lx)
CIE 174:2006 PreVit D3 3.66 µW/cm²
Lumen Reptil 1080 "pseudo-lx"
Vitamin D3 Degradation 5.04 µW/cm²
Broadbandmeters
Solarmeter 6.2 (UVB, pre 2010) 31.9 µW/cm²
Solarmeter 6.5 (UV-Index, pre 2010) 1.07
Leybold UVB 21.2 µW/cm²
Leybold UVA 79 µW/cm²
Leybold UVC 0.861 µW/cm²
DeltaOhm UVB 61.3 µW/cm²
DeltaOhm UVC 7.79 µW/cm²
Vernier UVB 6.05 µW/cm²
Vernier UVA 88.2 µW/cm²
Gröbel UVA 101 µW/cm²
Gröbel UVB 10.2 µW/cm²
Gröbel UVC 0.895 µW/cm²
Solarmeter 6.4 (D3) 3.34 IU/min
UVX-31 66.7 µW/cm²
IL UVB 0.0137 µW/cm²
IL UVA 85.5 µW/cm²
Solarmeter 6.5 (UVI, post 2010) 0.913 UV-Index
Solarmeter 6.2 (UVB, post 2010) 22 µW/cm² (Solarmeter Ratio = 24.1)
Solarmeter AlGaN 6.5 UVI sensor 11.9 UV Index
GenUV 7.1 UV-Index 0.735 UV-Index
Solarmeter 10.0 (Global Power) 4.65 W/m²
Solarmeter 4.0 (UVA) 1.09 mW/cm²