Baltimore County Collapse

[pyroknight]

I don't pretend to be an expert on TICs, but I was under the impression that they were near useless in detecting victims covered by anything (including water, snow, mud, rubble). Can someone with more experience and education shed some light on what use a TIC would be through a pile of 8 inch thick concrete block?

[old Bob]

Sorry,a TIC will be no use at all through concrete - they will detect tiny temperature differences that they have line of sight to and display them as a thermal image but the long wavelength infra-red they use does not pass through solid objects.Fortunately it does pass through smoke which is why we build TICs but it doesn`t go through glass,water or solid materials.If you put your hand on a pane of glass your body heat will soon conduct through it and create a temperature difference on the other side that the camera can see but it can`t see through the material.I hope this is clear - it`s an important question for all TIC users.

[S. Cook]

But...

There is a device that will detect a human heartbeat through concrete and other solid objects. I don't recall the name, but Clancy wrote about it in one of his books and the mfg demo'd it for me last year at ICHIEFS. I'll dig around and see if I can find the name.

[Russ Chapman]

The only way you can detect a body behind a solid object would be their body heat transfering through the object. I do not believe it could show through 8" of concrete.
I have "seen" a fire through glass on a house burn. This was not just heat on the glass but the actual fire start in a bedroom. The glass was old single pane window. I was using a Bullard TI at the time. The department I work for has both FIREFlir's and Bullard TI's. I have not talked with any of the TI engineers about this one yet so I cannot tell you why I could see the fire.

[old Bob]

Russ C. - this needs some explanation as all the TICs in use work on long wavelength infra red which doesn`t pass through glass.Try and look through any glass with your TIC and you`ll just see yourself!Glass is a mirror to the infra red we use.You will only see any temperature differences on the surface of the glass caused by warming behind it but that`s all.
But you could see the fire start,Russ?Strange!

------------------
old Bob M.

[S. Cook]

Gee, crow tatses bad - I've been had and stupidly passed it along.

The device I referenced (DKL Lifeguard) in my previous post is a fraud. It does not work. I apologize for any misinformation that may have been brought on by my post.

No wonder nobody but the rep could make the thing work at the ICHIEFS show...

Scott

references: http://www.skepdic.com/refuge/dkl.html

[TIman]

Hello All,

LWIR (Long Wave IR, 8-14 microns) will "pass" through old "Leaded Glass" single pane windows.

Anybody doubts that, I have it on video.

I can't give you an exact scientific explanation as to why, but I would guess it has something to do with the high lead content and method the way the glass is constructed.

Everybody else did a good job on the other descriptions.

Good Luck, Be Safe,

"TIman"
Mike Richardson
Bullard TI Training Specialist

For TI Training : www.safe-ir.com http://thermalimager.bullard.com/index06.cfm

[This message has been edited by TIman (edited 04-03-2001).]

[mwest3232]

Mike

I have also been able to see through glass that is very coated with soot (pieces that are kept in the burn building for training) My guess has always been carbon as the medium (like lead in older glass). I know it has surprised me when a student suddenly claims they can see through it. I've checked it, they've been right.

Happy imaging

[fireman_387]

If glass is clean you won't be able to see through it with a TIC, you are correct in carbon stained on there is the medium that is heated thus giving you the image.