Solarmeter 6.2 reading for T5 10.0

[beardedlarry]

I have a reflected T5 10.0 12 inches from basking platform and over a screen. After finding a chart here (which I can no longer locate), I purchased this setup for my dragon. I have since acquired a Solarmeter 6.2 and getting readings of only 37 at the basking site (sunbeam method). these seem woefully inadequate from what I am reading, but cannot measure UVI as were given on the chart.
I am considering supplementing UVB with a mercury vapor bulb to raise the output to an acceptable level. I have a lot of trouble navigating the yahoo group and cannot seem to post a topic. Can someone please help me out?

Thanks

 

[CooperDragon]

That does seem quite low. At 12'' using a ReptiSun 10.0 T5 with a reflector you should be getting somewhere in the neighborhood of 250 uW/cm2 and a UVI of approx 6.5-7 (which is on the high side of the best range anyway). Are you holding the meter directly below the bulb at 12''? Based on the charts on the UVB meter owner's group I'd expect readings of 37 uW/cm2 to be at over 2' away.

You shouldn't need to supplement a T5 with an MVB as that could produce dangerously high UVB output depending on your setup. I'd suspect either something is up with the meter or the bulb is defective or it's old and beyond it's useful life.

 

[beardedlarry]

The bulb is only one month old and is reading at 37 @ 12 inches under a screen and 67 without screen. Moving itin even one inch or so makes a huge difference. I am surprised at hte sensitivty changes by distance. I bought a exoterra mercury vapor 160 today and am getting 104 with both combined on the basking spot at 12 inches. How much degradation have you seen through a screen? He seems to like the light and is perky since I put the MVB in a little while ago. I guess there is no way for me to calibrate the 6.2; right? I don't want to O.D. him but wont he self regulate and go to the cool side or under cave if he needs it?

 

[CooperDragon]

67 is pretty low too but it's normal for the screen to intercept maybe 30-40% of the output depending on the type of screen. Something still seems fishy. Did you get your solarmeter directly from Solartech? I know they test/calibrate them before shipping. Some others may have another idea on this one but something sounds off to me. I'm basing this on the numbers for that lamp reported here https://www.dropbox.com/s/44gixt0zuwh45vo/ZooMedT5HO-ReptiSun10.pdf?dl=0

 

[beardedlarry]

67 is pretty low too but it's normal for the screen to intercept maybe 30-40% of the output depending on the type of screen. Something still seems fishy. Did you get your solarmeter directly from Solartech? I know they test/calibrate them before shipping. Some others may have another idea on this one but something sounds off to me. I'm basing this on the numbers for that lamp reported here https://www.dropbox.com/s/44gixt0zuwh45vo/ZooMedT5HO-ReptiSun10.pdf?dl=0

No, I bought it on amazon and it shipped from Carolina cages. I'm using a zoomed hood, so not sure if the reflectivity is low for that unit. The numbers are not too far off for an unreflected bulb.

 

[CooperDragon]

It's possibly the hood. You're right, the numbers you're getting are about right for not using a reflector and putting it through a screen so the meter is probably OK. It may be worth picking up a new fixture/reflector and see if that brings things up to par. Maybe try a Sunblaster NanoTech that is the correct size for your bulb and see if that makes the difference.

 

[beardedlarry]

It's possibly the hood. You're right, the numbers you're getting are about right for not using a reflector and putting it through a screen so the meter is probably OK. It may be worth picking up a new fixture/reflector and see if that brings things up to par. Maybe try a Sunblaster NanoTech that is the correct size for your bulb and see if that makes the difference.

Okay, good idea. Thanks.

 

[beardedlarry]

It's possibly the hood. You're right, the numbers you're getting are about right for not using a reflector and putting it through a screen so the meter is probably OK. It may be worth picking up a new fixture/reflector and see if that brings things up to par. Maybe try a Sunblaster NanoTech that is the correct size for your bulb and see if that makes the difference.

I just took readings without the reflector and its 37 without and 65 with reflector at 12 inches. One thing that had not occurred to me is that my fixture is the 14 inch one that only holds a 12 inch 15 watt bulb. All of the charts I have seen are from the 22 inch 24 watt bulb. I assume the lower wattage must make a difference, but I cannot find any information to verify my results. If I use a .625 multiplier to reduce the uvb, it doesn't quite match up to the charts.

 

[CooperDragon]

I don't have information to back that up but I'd assume that if you have the T5 it should provide similar output regardless of the length (increased wattage supports increased length?). I think the issue may be with the reflector.

 

[beardedlarry]

I don't have information to back that up but I'd assume that if you have the T5 it should provide similar output regardless of the length (increased wattage supports increased length?). I think the issue may be with the reflector.

I assumed that too, but now I'm not so sure. Reflector - it's certainly not as reflective as the one used on the chart. I am getting less than double where theirs was triple.

 

[Taterbug]

Was this the chart?
https://sites.google.com/site/thelizardmadness/lighting-guides

My info is a summary of Fran Baines work, she also gives the UV irradiance for her measures and you can find her charts by joining up here ((edit: I see you joined on the yahoo group hopefully you find a good deal of info there)). https://groups.yahoo.com/neo/groups/UVB_Meter_Owners/ or here https://www.facebook.com/groups/384134861721116/

There is a lot that will influence your readings, individual bulb, the electricity to and in your house, if the fixture is under or overpowered etc, even temperature apparently. My readings have been close but not an exact match to hers as I've worked on that chart and my other projects.

If I recall correctly longer bulbs are stronger than shorter ones, but I would have to verify that. Additionally where you measure along the length and angle around the bulb is important too. They are strongest right in the middle and your sensor needs to point directly at the tube.

Depending on the shape of the reflector it can have an influence on the light too, since your unreflected values are close
I'd also suspect it has something to do with the shape or material of the reflector. For example the Arcadia brand reflectors sold in the UK are asymmetric and more J shaped than one like the sunblaster which is very C shaped. This allows the fixture to be mounted in the front corner and still be very effective, whereas the sunblaster does best right overhead. Both will have a more "engineered" effect than a simple folded aluminum or foil reflector. However that shape can also make finding the reading challenging since it will vary across the shape of the reflector, if that makes sense. How far around the bulb the reflector warps and the quality of the metalic surface influences it as well. My sunblaster more than doubles the output whereas my T8 all-glass aquarium hood (folded aluminum) is about 50% more. What sort of material and shape is the reptisun hood reflector? Metal will reflect best and white paint or other material may not reflect much if any UVB at all.

I found the Eco-terra screen I have reduced by about 45% and since it's a physical blocking of the light a tighter mesh will block more than an open mesh.

 

[beardedlarry]

Was this the chart?
https://sites.google.com/site/thelizardmadness/lighting-guides

My info is a summary of Fran Baines work, she also gives the UV irradiance for her measures and you can find her charts by joining up here https://groups.yahoo.com/neo/groups/UVB_Meter_Owners/ or here https://www.facebook.com/groups/384134861721116/

Yes, that's the chart, and I originally found it while reading through your threads here and at UVB. The T5 10.0 UVI figures were what I used to come up with the ideal basking spot @ 4.7 screened and reflected. Based on the UVB readings related to a UVI of 4.7 for the same bulb (as shown in the files section at UVB), it should be around 160 reflected with no screen, or somewhere around 90 with a screen. So, I have to think that either the wattage and/or size of the bulb is a factor, or I have a defective meter.

If I recall correctly longer bulbs are stronger than shorter ones, but I would have to verify that. Additionally where you measure along the length and angle around the bulb is important too. They are strongest right in the middle and your sensor needs to point directly at the tube.

I would like to see that stated somewhere if you can find it. I think it must be the case since the 5.0 and 10.0 are percentages of total light output, which would vary by wattage.

I found the Eco-terra screen I have reduced by about 45% and since it's a physical blocking of the light a tighter mesh will block more than an open mesh.

That is about what I get too.

I just took a reading of a new 160 watt Solar Glo and it was about 130 at 12 inches. The chart on the box states it should be 260 at 12 inches. Thanks for your help. Not sure what to make of it all. My friend went lethargic on me a couple of months after getting the T5 and I have been to the vet for all kinds of treatments. when I finally got my meter, I was a little surprised to see the low UVB output.

 

[Taterbug]

About the length, I would be asking Fran to confirm, she's mentioned length being important in the past but don't remember where that was.

It does seem strange to get such variable results, If you are worried about the meter you can contact solarmeter and see what they charge for calibration or if they have a recommendation for checking it's accuracy. Which would be pretty unfortunate to have to do, considering you just got it. Hopefully it came with the certificate and calibration info when you bought it?

The 5.0 and 10.0 are related to the phosphor blend, rather than wattage. Again Fran would be able to better explain this.

 

[beardedlarry]

About the length, I would be asking Fran to confirm, she's mentioned length being important in the past but don't remember where that was.

It does seem strange to get such variable results, If you are worried about the meter you can contact solarmeter and see what they charge for calibration or if they have a recommendation for checking it's accuracy. Which would be pretty unfortunate to have to do, considering you just got it. Hopefully it came with the certificate and calibration info when you bought it?

The 5.0 and 10.0 are related to the phosphor blend, rather than wattage. Again Fran would be able to better explain this.

Ok, Ill try to ask Fran about length. Certificate says calibrated June 2015..

 

[Taterbug]

I hope she can help, I'll be watching your thread there too I'm interested to know what's up too.