Reptile & Amphibian Forums

Tracie and Frances are the light gurus.

The bulb I have and that someone else was asking about...

According to Tracie:

Solar Glo 125 watt which has very poor UVB anyway. These measurements are all at 12 inches as well:
Lamp 1- 25uW/cm2 UV Index 1.1

The solar meter is calibrated for human uv index readings. Not opaque skin desert dwelling Australian dragons. The uv index goes from 1-11. 11 being the extreme or the sun's max damaging uv.

Keep that in mind.

Hello Frances,

In my long anticipated purchase of the Solartech solarmeter 6.5 here are my results for our 1 Solar Glo 125 watt which has very poor UVB anyway. These are all at 12 inches as well:
Lamp 1- 25uW/cm2 UV Index 1.1

Here are my results for our two T-rex "standard economy" also. I was hoping that they would be acceptable, but our dragons wouldn't sit under them either. These results are for 12 inches also:
T-rex standard economy 100 watt:
Lamp 1- 50uW/cm2 UV Index 3.7
Lamp 2- 75uW/cm2 UV Index 5.2

So, since the UV Index wasn't horrible, I still feel that it was too high for the amount of UVB being emitted. I would like to know whether or not the wavelength dipped below 290 at any point. I would like to send these 2 over to you for further analysis, if that is ok?

Thanks.

Tracie

--- In UVB_Meter_Owners@yahoogroups.com, "lilacdawndragon" wrote:
>
> Hi, Tracie
>
> Good to see your results!
> In anticipation of your UV Index readings, here are my most recent Solar Glo and T-Rex "standard economy" results at 12 inches:
> (tested in March - April this year)
> Solar Glo 125W after 105hrs burn:
> Lamp 1 - 160uW/cm2 UV Index 6.1
> Lamp 2 - 29 uW/cm2 UV Index 0.6
> Lamp 3 - 25 uW/cm2 UV Index 0.6
> (but ExoTerra may have changed the specs yet again, to a higher output, I haven't tested any recently. They change specs very frequently and with no warning)
>
> T-Rex UV Heat "standard economy" 100W after 105 hrs burn:
> Lamp 1 - 55 uW/cm2 UV Index 3.8
> Lamp 2 - 119 uW/cm2 UV Index 10.5
> (This is a HUGE difference between 2 supposedly identical lamps. The second one I would regard as unsuitable for use at 12 inches...and the ratio of UVB: UVI is very high for both lamps.)
>
> >Let's just say that neither of my dragons would sit underneath of them.
> Interesting.... I put the safer of the two over my windowsill basking spot for a longer-term test, and neither of my two beardies would sit directly under it either... I did think that was strange since they always sit right under the ancient Osram Ultravitalux I have had there for several years....
>
> Best wishes,
>
> Frances
>
> --- In UVB_Meter_Owners@yahoogroups.com, "drache613" wrote:
> >
> > Hello Frances & Steve,
> >
> > Finally, I have a 6.2 meter & in a couple of weeks, will be getting a
> > 6.5 as well. Yes, I know, it is about time! )
> > I have measured the Solar Glo that I was using, well, I have 2 but one has a loose base so I did not want to mess with it. The base might break off.
> > My suspicions were validated with the 6.2 meter for the Solar Glo. The one that I did test only had tested these results:
> > 12 inches- 25uW/cm2
> > 10 inches- 32uW/cm2
> >
> > I should have done closer ranges, but probably still will. I saw what I needed to see. As soon as I get the 6.5 I will measure with that one
> > also.
> >
> > I also measured the 2 T-rex standard 100 watts but will wait to post any results until I see what the UV index is reading. Let's just say that neither of my dragons would sit underneath of them. Not a good year for lights.
> > Just thought I would post a few results now.
> >
> > Tracie
> >
>

Light meter group reading...

Hi, Ingo.

It's good to see your article here.
Your English translation is easy to understand. But is part of page 3 missing? There is a half-finished sentence at the top, and then a blank page..?

My only comment, which is something that you have indeed said, but I think might need even more emphasis:
It is vital to choose a lamp not only considering its UV output, but also considering the amount of heat and visible light it emits, as all three things are inseparable.

Your lamp list groups the lamps into the UV outputs appropriate for the Ferguson Zones, ie.
Zone 1: crepuscular or shade - UVI 0.7
Zone 2: partial sun or occasional sunbathing - UVI 1.0
Zone 3: partial to full sun - UVI 2.6
Zone 4: mid day baskers - UVI 3.5 and more

I think this is extremely valuable, and I hope these Zones will become widely accepted, but I'm a little bit concerned that people think about all aspects of lighting their species.

For example, Zone 1 animals are "crepuscular or shade"...which implies the diurnal ones get their UVB while walking about in shade, and the crepuscular ones get their UVB at dusk, or diffused into their daytime retreats as they sleep.

This doesn't mean they must be kept in gloomy tanks. Far from it...
I agree with Ingo that in large enclosures, a lamp like a Lucky Reptile metal halide could be used to provide a gradient from "full sun" to "full shade". But there are two problems with this, for shade dwellers.
1. The enclosure must be big enough to create a true gradient; shade dwellers may indeed benefit from being able to SEE bright "sunlight" at the far end of their enclosure, but they won't want to walk into it..
2. ..which leads to the problem that if the required level of UV is only found IN the bright light, these species are going to avoid it! This is why I think that cool, dim fluorescent tubes are better UV sources for Zone 1 and 2 species, and especially non-basking species.

In large enclosures, for non-baskers, I would want to use a halide for visible light, up in a small corner; but for their UVB, I'd cover a larger, diffuse area in their preferred temperature zone, using a tube. A UVI of less than 2.0 is typical of shade, not sunlight. In the wild this is provided by reflected UVB and diffused UVB from skylight.

In small enclosures, the light from a metal halide is likely to be very inappropriate for shade dwellers because they won't be able to escape the brilliance very easily.

The same rules apply for heat, from mercury vapour lamps especially.
This could affect animals from any Ferguson Zone. All species have very specific temperature requirements, and will not bask under the UVB lamp at the optimum distance for their UV requirements, if the temperature gradient under it isn't right for them.

I hope my comments add to, not detract from, what is a very good summary of the UVI from different lamps. And I know how long it takes to test all these lamps... a lot of work has gone into this article.

Best wishes,

Frances