What do you think? Could this be OK instead of going for a solarmeter 6.2??
http://www.zoomed.com/db/products/E...7czoxOiIwIjtzOjg6IlNlYXJjaF95IjtzOjE6IjAiO30=
http://www.zoomed.com/db/products/E...7czoxOiIwIjtzOjg6IlNlYXJjaF95IjtzOjE6IjAiO30=
jaizei said:The two links are to different products. The first is a UV index meter and the second measures UVB. I recall reading somewhere that the Zoo Med meters were just rebranded Solarmeters. So if true, they are basically a 6.5 and 6.2 respectively.
Is your question about the Zoo Med brand or about using a UVI meter in lieu of a UVB meter?
I think both are useful, but the 6.5 seems to be becoming more popular since they are more 'in tune' with the portion of the spectrum responsible for vit D synthesis (weighted, if you will).
Tom said:gtc, I've been looking into this a bit myself. The ZooMed model is a Solarmeter made and calibrated by the same guy in the same building, but with a ZooMed sticker on it. There are basically two types of Solarmeter in use. The 6.2 was the most popular one in years past and it measures UVb output in micro watts per square centimeter. Lately many people have been switching to the 6.5 model, and that one gives it readings as a UV index number. According to the person that I have been talking to that knows all about this stuff, the 6.5 model gives a more useful reading for a reptile owner as it is more tuned to read the specific type of radiation that our animals need to synthesize D3. I will ask her to comment on this thread for you.
Tom said:I will ask her to comment on this thread for you.
lilacdragon said:Hi, GTC and Tom.
Tom said:I will ask her to comment on this thread for you.
No problems....
Tom has explained this perfectly.
ZooMed are now selling the Solarmeter 6.5 UV Index Meter (still available direct from Solartech, purchase online or by phone for mail order, see www.solarmeter.com
The only difference is that the ZooMed meters have been given the ZooMed branding and have also been "tailored" for use with reptiles, by having a reptile-based guide printed on the label and associated documents. They are categorising the UV Index values in terms of the Ferguson Zones, four zones based on the basking behaviour and sun exposure (or not as the case may be) of different reptile species.
This is based on a scientific paper (a copy of which I've just sent to Tom) and is a concept being developed by the zoo community I work with, as well.
But if you find there is a price difference and this affects your choice, then be reassured, the Solarmeter 6.5 and the ZooMed UV Index Meter are exactly the same under the label.
Just as the original ZooMed "Digital Ultraviolet Radiometer" is a Solarmeter 6.2 in disguise
I highly recommend them both but Jaizei is right; for most situations the UV Index Meter will give you a better indication of safe and suitable UVB levels for your tortoise, both outdoors and indoors.
Best wishes,
Frances
...oh, Bouaboua... just saw your post...
DO NOT WORRY
Your 6.2 will be invaluable to you. I wouldn't be without mine. (And most people can't afford two!)
You'll just need a bit more research to find out what the readings mean. Because that gives you a reading in microwatts per square centimetre, which isn't quite as simple as the UV Index scale (as seen on weather forecasts)
Tom will probably be able to help you figure it out
Yes and no...Am I using it right??
Yes. You will get a very good idea of how the UVB changes with time of day and with the seasons - and find the best places for your tortoises to sun-bask.I use the 6.2 to measure the reading in various location and angle towards the sun and at the different time of the day out in my back yard and record it.
Then I compared with the UVB light lamp/tube provided output to measure the heights I hang my UVB lamps/tubes
and also let me know the time to lower or retire the old and replace a new.
bettinge said:I know you have worked with Bob Mac in the past. Can you comment on his lamps? Is he on the right track? Is there a "Best Bulb" with what we know today?
lilacdragon said:Hi, Bouaboua.
Yes and no...Am I using it right??
I'm sorry, guys. This is going to be a long post. But I honestly don't know any really simple way of explaining this, so I'm going to work through it as carefully as I can, although I know it's a sort of thing to do to anyone so late at night...
Yes. You will get a very good idea of how the UVB changes with time of day and with the seasons - and find the best places for your tortoises to sun-bask.I use the 6.2 to measure the reading in various location and angle towards the sun and at the different time of the day out in my back yard and record it.
Then I compared with the UVB light lamp/tube provided output to measure the heights I hang my UVB lamps/tubes
This is where the problem is, I'm afraid.
The Solarmeter 6.2 is designed to read the whole UVB spectrum. This includes shorter wavelengths, which are very effective at creating vitamin D, and longer wavelengths which have a less powerful effect. Sunlight has a lot of these longer wavelengths, which contribute a great deal to the reading on a Solarmeter 6.2.
But Reptile lamps almost all have a different spectrum from sunlight.
Some have a spectrum that is fairly similar - like most metal halide lamps and fluorescent tubes. Usually these have UVB spectra rather similar to strong tropical midday sunlight - powerful, but fine if positioned at the right distance.
Others, like many of the mercury vapour tubes and a few fluorescent tubes, have a much greater proportion of their UVB in the shorter, more reactive wavelengths. A small amount of this can have as powerful an effect on the skin as a large amount of longer-wavelength UVB.
But the Solarmeter 6.2 can't distinguish between "shorter wavelength" and "longer wavelength" UVB. It just gives you a Total UVB reading.
So... for some tubes and quite a few mercury vapour lamps, you don't want to match "full sunlight" values, with a Solarmeter 6.2 reading, because although (for example) 300 µW/cm² of sunlight is typical of sunlight at about 9.30 - 10.00am in the tropics, and safe enough.... 300 µW/cm² of UVB from some lamps would contain far too much shorter-wavelength UVB, and could even be hazardous for delicate eyes and skin.
The Solarmeter 6.5 is designed to respond more strongly to the shorter wavelength UVB (by a filter selectively reducing the longer wavelength UVB that reaches the sensor) its readings from lamps and from the sun are much better correlated.
So it is possible to "match" lamp and sunlight readings and be fairly certain that with a good quality lamp, the UV Index you are reading at the tortoise's basking level isn't far off the same "strength" as sunlight giving you the same reading.
Lots of people have asked me if there's a simple formula for converting a UVB reading (µW/cm²) from a 6.2 meter into a UV Index reading.
I wish there was! But because each brand of lamp has a slightly different spectrum, and "new improved" products will doubtless have new spectra too, it's an everlasting game. The only way to do it is to take sets of readings from a lamp, at the same distance, from both meters and plot a graph, from which you can get what's known as a regression formula... (a conversion formula).
Here are some samples, i.e., conversion formulas I've worked out for some lamps I've tested in the last three or four years, using my pair of Solarmeters. You're welcome to use these formulae but please bear in mind that there's no way I can be certain that your lamps are exactly the same as mine; and I only did the calculation on a tiny sample of lamps. So it's not really more than an estimate... (If anyone has 2 meters and some lamps, and wants to set to work plotting some more... please do! )
So: To get the approximate UV Index from a Solarmeter 6.2 reading, divide the Solarmeter 6.2 reading by the following numbers:
For a ZooMed Reptisun 5.0 or an Arcadia D3 6%UVB tube: 31.4 (average calculated from 4 lamps)
For a ZooMed Reptisun 10.0 or an Arcadia D3+ 12%UVB tube: 32.7 (average calculated from 14 lamps)
For a 100watt ZooMed Powersun : 12.2 (average calculated from 5 lamps)
For a 125watt ExoTerra Solar Glo: 19.4 (average calculated from 3 lamps)
For a 160watt ExoTerra Solar Glo: 16.7 (average calculated from 2 lamps)
For an ExoTerra SunRay Metal Halide lamp: 36.6 (average calculated from 2 lamps, one 50W and one 70W)
To find out what the approximate Solarmeter 6.2 reading would be, at a specific UV Index, multiply the numbers by the UV Index you need.
e.g. if you want a UV Index of 2 under a ZooMed Reptisun 5.0 tube, multiply 31.4 by 2.
So UVI 2 would read about 63 µW/cm² under a ZooMed Reptisun 5.0 tube....
.....ok?
For the sun, it's really complicated because it changes depending on the height of the sun in the sky. My formula requires a calculator!
But here are some calculations I made based on a large number of paired solar readings plotted on a graph...
UVI 1 = 57µW/cm²
UVI 2 = 108µW/cm²
UVI 3 = 155µW/cm²
UVI 7 = 301µW/cm²
UVI 12 = 437µW/cm²
UVI 15 = 521µW/cm²
For example.... suppose I wanted to create a basking zone with a maximum UVI of 3. This is like early morning sunshine about 8.30am in the tropics.
If I was measuring sunlight the Solarmeter 6.2 might read about 150 µW/cm².
To match that, I would need approximately:
98 µW/cm² with a ZooMed Reptisun 10.0 (3 x 32.7)
37 µW/cm² with a 100watt ZooMed Powersun (3 x 12.2)
Does this make sense to anyone or have you all lost the will to live
and also let me know the time to lower or retire the old and replace a new.
Yes, this is what the Solarmeter 6.2 excels in. Take measurements always at the same distance from the lamp, about once a month and you will be able to see how the UVB gradually declines with age.
In the first month, most lamps lose quite a lot, but after that the output from a good quality lamp of most types remains quite good for about a full year, only declining quite slowly... It's usual to replace a lamp when it's lost 50% of the UVB it had at first. With some types, e.g., ones that don't put out a lot of heat, you can keep the basking zone UVB the same over the year by lowering the lamp a little, as necessary, as its output falls.
By taking monthly readings you may discover that some good quality bulbs will keep going for well over a year, without needing changing.
Or when they are getting a bit low for a sun-basking species, you can use them over a shade-dweller - people can sometimes get 2 or even 3 years of life out of a good lamp in this way.
Best wishes,
Frances
lilacdragon said:You're welcome, Bouaboua.
I'm sorry I'm not around on this forum very often. You're a great bunch of folks.
Frances
Is the UVI level higher the better? At what level of the UVI would consider as danger? Or is there any danger level of UVI.
gtc said:Wow, thank you Tom and Frances. Frances, your posts have been extremely useful. I will be buying the solarmeter 6.5. I wonder if we could condense all this useful information into one post and maybe move it to the "important threads" section under "Tortoise Enclosure Lighting". Everyone should read this.