Re: Environmental-dosimeter weather housings

["George, Andrea K" <andrea.k.george@vanderbilt.edu>]

I just left Bechtel where I worked on a DOE project.  We 
used thick, white PVC casings with an end cap on top to 
protect from rain and snow.  On the bottom, it was covered 
with wire mesh.  We made cross-hairs inside the casing with 
wire and hung the TLD from the cross hairs.  Then, the 
casings were attached to the fences surrounding the sites.  
Our warehouse made the casings so I cannot supply a 
manufacturer.  

One thing you have to watch, at least with 
LiF TETLDs, is that if they are hung over concrete or 
asphalt it gets much hotter in the casing than if they are 
hung over grass.  Typical environmental temperature cycling 
can create a dose fade even though historical literature 
insisted that temperatures had to be greater than 150 deg 
F. I did a research project while at Bechtel and discovered 
that summertime temperatures inside the casings could get 
as high as 120 deg F.  This high temperature coupled with 
the cycling that occurs from day to night in the summer can 
create a significant dose fade at 200 mrem.  We saw this 
happen at the at a Southern site during a really hot 
summer.  So, I suggest you do whatever you can to keep them 
relatively cool.

Good luck!


On Thu, 22 Jan 1998 14:32:01 -0600 (CST) "Heinmiller, 
Bruce" <heinmillerb@aecl.ca> wrote:

> I'm looking for a supplier for 50 to 100 environmental-dosimeter weather
> housings for housing TLDs packaged in badges.  The badge dimensions (one
> per housing) are, conservatively, 8 cm x 6 cm x 2 cm.
> 
> The design should be simple (read "inexpensive") but must offer
> protection from sunlight, rain, and snow, and should be capable of being
> easily attached to existing fixtures such as fences and utility poles.
> 
> Supplier contacts or other useful comments should be sent to me directly
> at:
> 
> heinmillerb@aecl.ca
> 
> Bruce Heinmiller
> AECL
> Chalk River Laboratories, St'n 74
> Chalk River, Ontario
> Canada
> K0J 1J0
> 
> (613) 584-8811  + 4753
> fax (613) 584-1713

-----------------------------------------------------------------
Disclaimer: These are my ramblings and have not been
authorized by Vanderbilt University in any way.

Andrea K. George, Sr. Safety Officer
Hazardous Materials Management
Vanderbilt University
Email: andrea.k.george@Vanderbilt.Edu