UV Readings from Arcadia T5 Slimline Luminaire 39w

[Ozric Jonathan]

We've had a bit of discussion before about whether or not the gradual accumulation of uvb exposure over the course of many hours equates to the same as more intense uvb for a shorter time.

I don't think we know.

[yuna1971]

Rossy - Does the reading fluctuate (with any significance) depending on what point on the the tube you are measuring at ?? Ie - half way across, 2/3rds across etc etc ???
xx

[TillyTortoise]

Originally Posted by yuna1971

Rossy - Does the reading fluctuate (with any significance) depending on what point on the the tube you are measuring at ?? Ie - half way across, 2/3rds across etc etc ???
xx

Yes, there is a huge difference in uW/cm² towards the ends of the tube, only reading around the 90's at 12 inches.

[yuna1971]

I see.
I don't see the benefit really of these. It all depends (much the same as a combined bulb) where the tortoise decides to sit with how much UV he is going to get.
Also, is it fair to say that sometimes they don't want to be flushed with UVB. Much preferring just general warmth. I've noticed Lily - with the Arcadia combined on + a ceramic 100w angled in (at the basking area) that he will quite often sit away from the main spread of the combined...preferring to warm under the ceramic.?
Would this sort of strip therefore not be giving a tort much choice but to be doused with UVB whether they like it or not??
Just wondered...xx

[Arcadiajohn]

Hi, let me clear up a couple of points,

Firstly T5s use very active phosphors and will take around 100hours to reach full power.

They are guaranteed to be effective at the upper level for 12 months.

They emit more usable UVb at the right wavelength I.e 297nm than a M.V but over a vastly greater area. This opens up a MUCH safer and MUCH wider photo gradient that is detectable and usable by the animal.

The first inch or so of any lamp will have less output than the rest of the tube as this is where the electronics are seated. With the 54w lamp you have about 42" of high output emission.

The advice from us is to use the light and shade method. This means generating a wide high strength area that is in line with the thermal gradient. So heat and light at one end, cool and Shade at the other. Then let the animal self regulate though out the enclosure. We recommend using a fitting half to two thirds the length of the enclosure to make use of this natural method. This is far more obtainable to the animal than the 2-4" usable area from M.V only methods.

We advice that M.V/halide lamps are used as boosting zones as a hot boosting zone that can be chosen and used at the animals request.

Be care when taking readings as different batch meters will show differing readings. Also this reflector has a sweet spot under the lamp where as the Arcadia separate system is asymmetric.

We then set the fittings at a safe height. These fitting actually provide a usable down force to about a meter! We then use decoration and sub straight to elevate the species to within the target index of the lamp. So for this type of species 12-15" of the lamp at the basking spot.



Looking forward to seeing this progress!

John

[Ozric Jonathan]

EDIT - as John has now replied, I decided to add to mine.

I haven't found much variation of uvb output along the tube though maybe Ross is being more systematic than me in his measuring and I'm not using the luminaire.

In connection with Rachel's point, yes I agree that this tube does cover really quite a wide area. To my way of thinking, the wide spread of light is an advantage of this tube. I like to hang it at a minimum of 12" so that the uvb is not hugely intense but is very significant over a wider area.

For me anyway these tubes are good because they deliver very good amounts of uvb without the tortoise having to be subjected to the drying effcts of mvb bulbs all the time. And they can move about a lot more without being outside the small zone of uvb that a combined lamp provides.

There should always be the option for the tortoise to go somewhere away from the tube without being too cold. This is easy to say but with smaller enclosures it can be difficult.

Where Arcadia John's suggestions get tricky for me is when we says that we could use additional mvb lamps for heat and for highs of uvb. If the mvb is within the range of the tube then we get a combination of uvb sources and its going to be a challenge to get a proper measure of it. If it's not within the range of the tube then it's just an mvb sitting there which needs a heat source alongside it since the arcadia mvb's do not produce much. The 80 watt mini mvb producing hardly any heat at all. Now we are in the realm of multiple gadgets with tubes, mvb's and halogen lights all needing to be set up and looked after. I don't have any problem wiht that but for some keepers it's a lot of cash outlay and time spent fiddling.

[egyptiandan64]

Interesting points

The lamps are close to the 100 hour "maximum" output as they had been on 84 hours when Ross took the reading, 7 days/12 hours a day.

Was just wondering why a hide at each end (warm end and cool end), with light on the whole enclosure during the day, wouldn't work just as well as shade on the cool end. Not quite getting why a tortoise would want to be cool and shaded at the same time, especially at this time of year.

I do love the meter reference

Danny

[yuna1971]

Maybe a halogen flood and the Arcadia tube would work?
I'm still yet to be convinced that the tube will benefit the tort more (over that wide an area, with that fluctuation in output) compared to a normal combined Arcadia bulb. If its secondary function is for light and not solely on UVB then why not get a low dose 2% strip, a combined and add your heat with either a ceramic or low wattage halogen?
I see the importance of having that good spread but if your fixing it high anyway, in terms of UVB - is it better or no worse than having a combined?
Yes we would provide the shaded/cool/sleeping area but depending on size, aside from that area there isn't really anywhere for tort to go to just want warmth, and not necessarily be soaked in UVB apart from going back to bed?
Is the idea of the strip meant to simulate a certain time of day?
Again sorry if I have misinterpreted things or misunderstood points here, I'm just curious and wanted to understand the reasons and purposes of them vs MV combined bulbs.

I'm probably babbling twaddle anyway....

xx

[yuna1971]

I'm sure I read someone saying that sometimes they don't want to be immersed in UVB all the time. I am guessing...but wouldn't even conditions 'in the wild' have cloudy days?
Do torts spend all day every day basking in bright sunlight ? Or do they seek out areas of terrain that's warm, but not necessarily exposed right out in the sunlight.
I hold my hands up, that's just me wondering. I haven't studied their behaviourisms in the wild, so it's guesswork. xx

[Ozric Jonathan]

OOOh nooo I don't think you are babbling at all Rachel.

In answer to the question at the top of your post I say the answer is yes. It is vitally important to put the tube at the right height. If the tube is at 12" and there is a halogen lamp or something similar for a heat source under it then the tortoise will be getting plenty of uvb exposure.

It's also, as you say, a light source and it does very well at that as well.

Ross will provide more accurate information but from my readings these tubes are very stable in their uvb output and it seems they don't suddenly give up on the job.