UVB inside glass enclosures

pagan queen · 19-08-2012, 11:32 AM

If a tort or other reptile for that matter is kept in a glass fronted enclosure as opposed to an open topped one, do they get more UVB rays?
My thinking is that as glass does not allow the rays to penetrate in, it also doesn't let them out. So in an open top enclosure all the rays just "float" away where as they are bounced around inside glass. How long do they stay in there and does the strength decrease?

Merlin M · 19-08-2012, 11:52 AM

really not sure, glass (unless it has a good UV filter) will let some UV through, but will block most of it. But it would seem logical that it is reflecting what it is not letting through...

**Alan1** · 19-08-2012, 01:09 PM

I don't know that it makes a difference but they will disappear no matter what I assume otherwise in a viv you'd only need a lamp on for a minute and the UVB would stay there all day until the door was opened

UVA would escape out glass anyway, it can go through glass but UVB can't.. not modern day normal glass anyway

Kirkie · 19-08-2012, 05:05 PM

The electrons in the molecules of glass absorb ultra violet light in the "B" wavelength. It doesn't reflect it back. *Light in the UVb wavelength does "bounce" which is why you can record UVB levels in the shade and you can get condensed levels of UVB around reflective surfaces.

I think thats right.

pagan queen · 19-08-2012, 06:36 PM

So does that mean the light would bounce off the back of a wooden viv until it hits the glass at the front? Would this cause a higher level of UVB inside a viv?

Kirkie · 19-08-2012, 06:44 PM

Maybe, slightly. Were talking about things happening at the speed of light so it's not going to build up in a viv. Light travels in straight lines. Any light bouncing off the wood would richochet round (at 299,792,458 meters per second) until it hit the glass and was absorbed.

Geomyda · 19-08-2012, 07:30 PM

For those, whom have yet to see Francis Baines give her excellent presentation on Environmental lighting for Chelonia, I strongly recommend booking a seat at the forthcoming Conference being held at Colchester Zoo on the 17th November 2012.
This subject is frequently questioned and debated but few are better at explaining it than Francis.

**Alan1** · 20-08-2012, 03:36 PM

There was a Panorama programme recently about the damage UVA does to your skin when driving your car with the windows closed

EDIT> actually it was Horizon http://www.bbc.co.uk/programmes/b01lbgrp

Catwoman63 · 21-08-2012, 08:42 AM

What good and important question, very interesting subject x

roboticnat · 21-08-2012, 09:00 AM

i'm not a 100% but i read somewhere that glass blocks i tihnk it's around 95 - 97% uv going through it

19-08-2012, 11:32 AM	#1
pagan queen Senior Member Adult Join Date: Jun 2010 Location: Kent Posts: 6,073	UVB inside glass enclosures If a tort or other reptile for that matter is kept in a glass fronted enclosure as opposed to an open topped one, do they get more UVB rays? My thinking is that as glass does not allow the rays to penetrate in, it also doesn't let them out. So in an open top enclosure all the rays just "float" away where as they are bounced around inside glass. How long do they stay in there and does the strength decrease? __________________ 1.0.1 TG Ibera 1.0.0 Chinese Frise dog 0.1.0 African Grey Parrot 0.1.0 Hahns Macaw 0.1.0 Pearly Conure 0.2.0 Guinea Pigs 0.2.0 Chickens 1.0.0 Bearded Dragon 7.4.0 Budgies 1.1.0 Cockatiels 1.3 Kids 1 Husband

19-08-2012, 06:36 PM	#5
pagan queen Senior Member Adult Join Date: Jun 2010 Location: Kent Posts: 6,073	So does that mean the light would bounce off the back of a wooden viv until it hits the glass at the front? Would this cause a higher level of UVB inside a viv? __________________ 1.0.1 TG Ibera 1.0.0 Chinese Frise dog 0.1.0 African Grey Parrot 0.1.0 Hahns Macaw 0.1.0 Pearly Conure 0.2.0 Guinea Pigs 0.2.0 Chickens 1.0.0 Bearded Dragon 7.4.0 Budgies 1.1.0 Cockatiels 1.3 Kids 1 Husband

20-08-2012, 03:36 PM	#8
Alan1 Super Moderator Adult Join Date: Dec 2008 Location: Sunny Scotland Posts: 21,512	There was a Panorama programme recently about the damage UVA does to your skin when driving your car with the windows closed EDIT> actually it was Horizon http://www.bbc.co.uk/programmes/b01lbgrp Last edited by Alan1; 20-08-2012 at 03:43 PM.

21-08-2012, 08:42 AM	#9
Catwoman63 Senior Member Adult Join Date: Jan 2012 Location: South East England Posts: 6,739	What good and important question, very interesting subject x __________________ BEV XXX 0.3.0 - T Horsfieldii (Xena, Zelda & Lilly) 2.2.0 - TG Terrestris (Zeus, Astreus / Zagreus & Alexia) 1.2.0 - Zebra Finches (Gunner / Bonnie & May) 0.1.0 - SBT (Hazel) 1.0.0 - FBD (Ted)

21-08-2012, 09:00 AM	#10
roboticnat Member Incubating Join Date: Nov 2010 Posts: 208	i'm not a 100% but i read somewhere that glass blocks i tihnk it's around 95 - 97% uv going through it __________________ 0.0.2 indian star 0.1.0 florida soft shell 0.1.0 yellow belly sliders 0.0.1 Sulcatta

19-08-2012, 11:52 AM	#2
Merlin M Senior Member Adult Join Date: Feb 2012 Location: Edinburgh Posts: 4,186	really not sure, glass (unless it has a good UV filter) will let some UV through, but will block most of it. But it would seem logical that it is reflecting what it is not letting through...

19-08-2012, 01:09 PM	#3
Alan1 Super Moderator Adult Join Date: Dec 2008 Location: Sunny Scotland Posts: 21,512	I don't know that it makes a difference but they will disappear no matter what I assume otherwise in a viv you'd only need a lamp on for a minute and the UVB would stay there all day until the door was opened UVA would escape out glass anyway, it can go through glass but UVB can't.. not modern day normal glass anyway

19-08-2012, 05:05 PM	#4
Kirkie Senior Member Adult Join Date: Mar 2008 Posts: 4,887	The electrons in the molecules of glass absorb ultra violet light in the "B" wavelength. It doesn't reflect it back. *Light in the UVb wavelength does "bounce" which is why you can record UVB levels in the shade and you can get condensed levels of UVB around reflective surfaces. I think thats right.

19-08-2012, 06:44 PM	#6
Kirkie Senior Member Adult Join Date: Mar 2008 Posts: 4,887	Maybe, slightly. Were talking about things happening at the speed of light so it's not going to build up in a viv. Light travels in straight lines. Any light bouncing off the wood would richochet round (at 299,792,458 meters per second) until it hit the glass and was absorbed.

19-08-2012, 07:30 PM	#7
Geomyda Senior Member Adult Join Date: Aug 2008 Location: Surrey Posts: 2,094	For those, whom have yet to see Francis Baines give her excellent presentation on Environmental lighting for Chelonia, I strongly recommend booking a seat at the forthcoming Conference being held at Colchester Zoo on the 17th November 2012. This subject is frequently questioned and debated but few are better at explaining it than Francis.

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