I read a thread about a forum member who had brought a sensor that records the levels of UV.

Would be great if they could test a few bulbs and let us know for sure which is better!

 

that may be me?

however, if you have a read of the thread now there are some more interesting facts coming to light. overall UVB level is one way of measuring a tube, however its not the be-all and end-all. the wavelength of the UV is equally as important, some bulbs put out far too much in certain wavelengths to the point that it could be dangerous. despite the overall UVB levels being acceptable. on the other hand, some tubes may put out less overall UVB than is acceptable compared to a wild natural environment, but still produce enough in the specific wavelengths at which vitamin D3 synthesis occurs to be acceptable.

it seems there is more to UV than meets the eye, and a UVB meter alone is not enough to paint an accurate picture. it is however good for monitoring degradation of bulbs, and for basic UVB analysis. someone else has been doing it for a lot longer than i have, armed with much more knowledge and far better equipment though. UV Lighting for Reptiles: UVB Fluorescent Tubes Test Results

Zoo Med Reptisun 10.0 tube does seem to come out on top by quite a substantial margin however that is only a measure of total UVB output, which can be skewed slightly by the results being "averaged" by the UVB meter. they did also test it for UV Index levels, and at 100uW/cm^2 it put out 3.1 which is fairly low, UVI levels in the UK can reach as high as that on a sunny autumn day. however that still makes it one of the best tubes on the market, the Arcadia D3+ 12.0 wasnt on the test unfortunately to compare. the compact versions of the Reptisun bulbs however have an incredibly high UVI compared to the tubes, which would make them potentially dangerous at close distances.

 

were have you look cuz everywhere i have looked arcadia is more expensive than zoo med. im using arcadia but just ordered zoo med 10