> Hi Fran, Am I reading this correctly in that there is more UVB in the higher section (310-320) then UVA at the 360+ spectrum? if so, do have a UVAuW/cm2 number?
Yes, you are reading that correctly, BobMac.
I don't have any broadband meter which will give readings for those specific wavelengths so I have to use data from the spectra. Sarina's calculator has enabled me to get the information from spectra in her database, but I haven't been organised enough to upload the spectra from the lamps in that report.
So the next best thing: a breakdown of the spectra from lamps already in the database:
(a) an Arcadia D3+ 12%UVB T5 24watt lamp )similar to the ZooMed 10.0 T5) at 10cm distance:
280-309nm UVB = 30.2 uW/cm2
310-320nm UVB = 130.0 uW/cm2
321-360nm UVA = 385.2 uW/cm2
361-400nm UVA = 47.8 uW/cm2
(b)an original ReptileUV Mega-Ray 275W mercury vapour lamp at 30cm distance:
280-309nm UVB = 147.3 uW/cm2
310-320nm UVB = 889.6 uW/cm2
321-360nm UVA = 1,498.4 uW/cm2
361-400nm UVA = 10,208.0 uW/cm2
Mercury vapour lamps produce a simply enormous "spike" of UVA light at 365nm, which is just within the visual range for most reptiles. They have little or no UVA above 365nm, however.
Fluorescent tubes also have that spike, from their mercury vapour, but it is nowhere near as powerful; and there are very few tubes which produce much UVA above 365nm, either, because almost all phosphors used to generate UV for reptile lamps don't also emit long-wavelength UVA and short-wavelength visible light (purple and deep blue).
It has been suggested by some people that a phosphor emitting these wavelengths should be added to the lamps. Unfortunately, long-wavelength UVA, purple and blue are the most damaging to the retina of the eye (e.g. http://www.mdsupport.org/library/hazard.html#problem)
and also, UVA is particularly bad for predisposing to certain skin cancers and causing immune suppression, in humans at least.
According to Wikipedia:
"In the past, UVA was considered not harmful or less harmful, but today it is known it can contribute to skin cancer via indirect DNA damage (free radicals and reactive oxygen species). It penetrates deeply, but it does not cause sunburn. UVA does not damage DNA directly like UVB and UVC, but it can generate highly reactive chemical intermediates, such as hydroxyl and oxygen radicals, which in turn can damage DNA. ...... UVA is immunosuppressive for the entire body (accounting for a large part of the immunosuppressive effects of sunlight exposure), and UVA is mutagenic for basal cell keratinocytes in skin."
So I don't think it would be a wise move to increase the UVA emission from tubes, which are normally not bright enough to cause the animal to avert its gaze.
The most "sun-like" provider of UVA is a good metal halide lamp, which has a great deal of UVA throughout the whole range, increasing in intensity with increasing wavelength. These are also far too bright to look into, which helps in preventing eye damage.
>>Also, it should be noted that the UK Mega-Ray you tested was not altered like the US version you recently tested for me. It would be nice to see those results posted as it has been my production bulb for two years now.
I'll look out the report and post it in the Files here, as soon as I can.
>>And yes, as I have told you there is a new Mega-Ray or actually a reproduction of the original Mega-Ray with the coating on the inside developed. I still have some tweaking to do on the mag oxide to get them as close to 35-1 as possible but the first US bulbs will be available in a couple of weeks with whole sale back.
I shall look forward to testing one as soon as they are launched.