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Re: Dosimetry
Jim Abraham correctly assessed that the following statement is
unfounded.
> > Also consider the fact that quarterly TLD's have to be more stable and
> > better able to "hold a dose" over a long period of time than monthly ones.
> > This probably means that the TLD and supporting materials are more
> > expensive than stuff that only has to last a month.
In actuality, the TLD is stable for any time period. The only
technical requirement is that the appropriate fade factor correction
be used for the length of time the badge was in the field. The fade
reaches equillibrium in about 120 days, therefore, after that time,
there is no change in fade correction applied.
TLDs are accurate well into the future. However, for regulatory
reporting requirements, or, just to know, the longest time a TLD
should be worn is 1 year, without having it processed. I provide
annual badges to customers who are wearing the badge for individuals
classified as "not requiring monitoring". I also provide semi-annual
TLDs to several power reactors. So, as Jim suggested, the statement
above is not accurate. A TLD can be worn for any time period, and be
stable and accurate.
As far as films, I provide quarterly film to those individuals in
states where film need not be processed every month. There are only a
handful of states that mandate only monthly film is allowed. The
bottom line on quarterly film is how stable a process do you have,
how good are your energy/dose curves and how well does the facility
where the quarterly film is worn maintain environmental conditions. I
can assure you all that quarterly film is very cost effective, and
will meet most of what Jim asked about in the original posting.
------------------------------------------------------------------------
Sandy Perle Tel:(714) 545-0100 / (800) 548-5100
Director, Technical Extension 2306
ICN Worldwide Dosimetry Division Fax:(714) 668-3149
ICN Biomedicals, Inc. E-Mail: sandyfl@earthlink.net
ICN Plaza, 3300 Hyland Avenue E-Mail: sperle@icnpharm.com
Costa Mesa, CA 92626
Personal Website: http://www.geocities.com/scperle
ICN Worldwide Dosimetry Website: http://www.dosimetry.com
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