This Solarmeter is good for tracking the degradation of your reptile's heat lamp. I have a leopard tortoise who spends a large amount of time inside (he's a youngster). I got this to check his lamps. I find a lot of tortoise keepers prefer the solarmeter 6.5 now, which gives you a UV index. The 6.2 measures the UVB across the entire wavelength range (280 - 320nm). UVB is the quickest type of UV light to degrade in the lamps and the type that helps them metabolize D, but the vitamin D metabolism happens across a relatively short range of wavelengths, which the Solarmeter 6.5 is more sensitive too. The 6.2 was the preferred model (and only model) for a long time, so there is ample information on the Internet about it and its use. I really think the 6.5 is only preferred now because it's a bit easier to use and understand, though the 6.2 is just as accurate and just as helpful for reptile keeper purposes.

There is some variability between lamps with the 6.2 because of the wide range of wavelength it senses. Two lamps could have the same readings, but one could be better for reptiles because it has more short range UVB and the other has more long range UVB. That kind of information should be available from your light manufacturer. The 6.5 is more sensitive to readings in the short range. That being said, reptile keepers are usually testing the same lamp for degradation over time, and the 6.2 would be more accurate there because it specifically tests UVB which degrades faster. It really depends on your purpose (but either is probably accurate enough to ensure your reptile has sufficient UVB). You cannot, however, use the 6.2 to gauge the sun and compare it to your reptiles lamp. Sun will give a much higher reading than any lamp because it has a lot of high wavelength (useless for vitamin D) UVB, but your lamps don't. Lamps are usually designed to produce the effective, shorter, UVB.

That being said, when I got this I also ordered a new lamp and I tested the lamp and recorded that number and will check periodically. According to Zoomed, tropical species should have around 13-30 microwatts/cm2 for 10 hours a day and desert species 13-150 microwatts/cm2. My year old lamp registered 8, but my new one measured around 20 microwatts/cm2. The sun shows 170+ microwatts/cm2. The readings will vary by lamp, so you'll have to test to see what the normal is for your lamp (if your lamp is a common one, a google search will probably give you that information)

The readings will vary based on the distance you are from the lamp. You really should test at your reptile's distance (ie: for a tortoise, test at shell level, not right up next to the lamp. A chameleon can climb higher, so a reading from a perch would be appropriate). There should be a UVB gradient that they can move in and out of, just like with temperature gradients.

if you keep a reptile this mirror is for you, know exactly how much UVB rays your baby is getting. Again this works great with UVB Bulbs.
It can save you money in the long run, When UVB bulbs getting into the 30.00 to 60.00. I see you starting to save money at the 6 months mark. As most bulbs say you must change them at 6 months. With this you will know if your bulbs need to be changed.

llso you will know if your Pet is getting what it needs from UVB rays with out the guess work. A+++

This Solarmeter gets one star simply because I couldn't figure out how to use it. I ended up returning it and getting the newer one that measures the uv index. This one didn't even come with any directions. Unless you know what you're doing or want to get a box with a button that presses in I recommend getting the 6.5 version

Edit: Just so I don't sound like an idiot, I understand that when you push the button and face the sensor up it gives you a number. This does work fine. I'm trying to use this uv meter to measure the uvb output on the lamps in my reptile cages. I had no idea if the number I was getting was high or low or what the heck it meant at all. There's no gauge for scale included in the package. My only option would have been to get brand new lamps for all my cages, measure the output, and then check it every so often as the uvb output decreased until I thought the number was too low (again only a guess) or until it was 0 which was not acceptable. All of my cages are also set up differently so it would have meant assuming that the setup and light strength at the measuring spot was ok to start with.

pls see the pics i took recently, why there is still reading on the screen when the holster is closed， is this normal or poor quality?

This tool is a necessity for your exotic, uvb-dependent pet. If you don't measure the UV exposure you're only guessing, and this meter works very well. Strongly recommended.