How to use UVB meter

[FrankiesMom]

Hello from rainy dreary Florida!

I have been reading the forums and it appears that the Solarmeter 6.5 is the way to go. I see there is a Solarmeter 6.5R as well. Any thoughts on which is better or if there is even a difference? Also, my real question is, how do I use this thing once I receive it? I am assuming that I point the meter at the UVB bulb itself ... and then for a baby leopard tort, what number am I hoping to see on the screen of the meter to assure my UVB output is still good?

Thank you in advance for your expertise and advice. It is greatly appreciated!

 

[Yvonne G]

I have no idea because I don't have one and have never even seen one, but my guess is you want output at the tortoise's level, so you'd point it at the substrate where the light hits. @Markw84 ? @Tom ?

 

[Markw84]

Hello from rainy dreary Florida!

I have been reading the forums and it appears that the Solarmeter 6.5 is the way to go. I see there is a Solarmeter 6.5R as well. Any thoughts on which is better or if there is even a difference? Also, my real question is, how do I use this thing once I receive it? I am assuming that I point the meter at the UVB bulb itself ... and then for a baby leopard tort, what number am I hoping to see on the screen of the meter to assure my UVB output is still good?

Thank you in advance for your expertise and advice. It is greatly appreciated!

There is no difference other than the reptile marketing stickers decorating the 6.5R meter. Otherwise, both the same.

The meter has a sensor on the very top as you hold it upright. Be sure that is unobstructed and hold the meter with the sensor on top pointing at the light source. Have the sensor as close to tortoise level as possible as that is the reading that is important to you - what UVI reading the tortoise will be exposed to. Simply press the button and hold, and the meter will give you the UVI reading at that spot. For a leopard tortoise anything in the 3.0 - 5.0 range is what I would want.

 

[Tom]

Mark pretty well answered your question, but I want to elaborate on the desired number.

There is much debate and not a lot of scientifically known answers about UV levels and tortoises. Many people have different opinions, experiences, and preferences on the matter.

There are a million "shades of gray", but two predominant ways of looking at it:

1. Lower levels of say 1 to 3 on the meter, and run the bulb all day long.
2. Higher levels of say 5-7 on the meter, and only run it for 3-4 hours mid day on a timer to simulate the mid day spike in brightness and UV that occurs out side in the real world.

Both methods work and both methods can provide enough UV for the tortoise to synthesize D3, which is the whole point of using the bulb. I prefer method two, but there is nothing wrong with method one either.

Also, since the meter is taller than a small tortoise, I dig a hole in the substrate directly under the bulb and put the bottom of the meter directly on the bottom of the enclosure to get it as low as I can get it. I get my reading and then fill the hole back in.

Have fun with your new meter. Take it out side and watch what the UV levels do throughout the day and throughout the seasons. I was shocked to see how low the levels were in the mornings and afternoons, and also how much lower mid day levels are in winter compared to summer.

 

[Yvonne G]

So, just to be clear: You place the meter on or slightly below the substrate pointing back up at the light?

 

[FrankiesMom]

Awesome instructions and feedback from everyone. I figured spending $200 on the meter would be cheaper in the long run than just automatically replacing my UVB bulb every 6 months with no actual data to confirm that it's no longer working. I'm hoping that I'll be pleasantly surprised by the useful life of my bulb! Thanks to everyone for the quick and very helpful responses.

 

[Tom]

Awesome instructions and feedback from everyone. I figured spending $200 on the meter would be cheaper in the long run than just automatically replacing my UVB bulb every 6 months with no actual data to confirm that it's no longer working. I'm hoping that I'll be pleasantly surprised by the useful life of my bulb! Thanks to everyone for the quick and very helpful responses.

You are correct. I have regular 10.0 bulbs still producing the same low UV readings after 3 years of daily use.

My Arcadia 12% HO bulbs lasted 2 years of daily use when their levels began to drop. I simply lowered the bulbs a couple of inches and that brought my UV readings right back up and they are still going strong.

 

[Markw84]

So, just to be clear: You place the meter on or slightly below the substrate pointing back up at the light?

The meter itself is about 3-1/2" tall. The sensor is on the top of the meter when the digital readout is facing you. So to get the reading at tortoise level, If the tortoise is only 2" tall, you need to dig it into the substrate a bit to get the top of the meter at 2" (tortoise level). With a T5 HO bulb, the proper readings are in the 20" away from the bulb range. A difference of a few inches up or down will increase/decrease your reading 0.5 UVI or so. But with a T8 10.0 bulb, the same readings require about 10" away from the bulb. In those closer ranges, a few inches can make a substantial difference in reading! Hope that is understandable. The TMI reason is that the UVI reading geometrically increases the closer you get, not a linear increase. 1/2 the distance closer is not 1/2 the UVI reading but about 10 times more. Another reason why I prefer the T5 HOs as they give a broader basking range at the levels we want.

Also - agree with all @Tom added - thanks! I use method #2 as well.