Re: Dosimetry

[Bob Hearn <rah@america.net>]

12,000 badges are not required to support monthly dosimetry for 1,000
monitored.  A minimum of 2,000 are necessary to support contiguous
changeout, plus some additional for delay, loss and logistics issues.  This
is the same number of badges needed to support quarterly changeout.  The
same capital investment (time value of $) is tied up in both cases; the
primary difference being the attrition factor for 3x more reads of a badge
under the monthly program, along with the attendant per-read processing
costs.  Genral ongoing QC (e.g., NAVLAP) and records maintenance do not
produce a significant reduction with quarterly changeout intervals.

There is thus a lesser cost to support quarterly monintoring, however, the
relationship is far from linear.

Bob Hearn

At 06:17 PM 2/11/00 -0600, you wrote:
>Sandy Perle said the following:
>
>There is a
>> carrying cost for the TLD. If the TLD is out in the field for 3
>> month, or 6 months or as long as a year, it can not be used for
>> another individual until returned. Therefore, other inventory is
>> necessary to make up the variance in utilization potential.
>
>O.K. - To use your example.
>
>I have 1000 badges delivered and returned to my vendor every month. 
>That's 12000 badges/ yr.  I move to quarterly, so now I have 4000 badges
>delivered every year.  The vendor has a surplus of 8000 badges for the
>year just from me moving to quarterly.  You stated, "it can not be used
>for another individual until it is returned. Therefore, other inventory
>is necessary to make up the variance in utilization potential".  I'm
>telling you the vendor has a surplus of 8000 more badges now than
>before.  "Other" inventory is not needed to make up for the variance
>because the vendor now has my 8000 EXTRA badges.  It sounds like you are
>suggesting that the customer has to pay for the badges that are being
>stored and not used ????  I thought it was the vendor's job to support
>their product and solicit their services.  Sandy, this still appears to
>be a money issue whereby the cats at the top keep the revenue comming in
>for a fraction of the work being done.
>
>Respectfully,
>-- 
><><><><><><><><><><><><><><><><><><><><><><><><><><><><>
>James P. Abraham
>Alt. Radiation Safety Officer
>Radiation Control Office - Environmental Health Serv.
>Colorado State University - Fort Collins, CO 80523-6021
>
>Phone: 	(970) 491-3928		Fax: 	(970) 491-4804
>email: 	jimabe@lamar.colostate.edu
><><><><><><><><><><><><><><><><><><><><><><><><><><><><>
>
>Sandy Perle wrote:
>> 
>> Jim Abraham said the following:
>> 
>> > So the vender provides a service;
>> > you pay a set rate for that serivice;  after so much time, you request
>> > 1/3 the service.
>> 
>> As I wrote earlier, the cost wouldn't be directly proportional to the
>> increased or decreased frequency. For an example, if TLDs are worn
>> for a monthly frequency, and this is changed to a quarterly frequency
>> .. the cost will not drop down by 1/3 for the quarter. There is a
>> carrying cost for the TLD. If the TLD is out in the field for 3
>> month, or 6 months or as long as a year, it can not be used for
>> another individual until returned. Therefore, other inventory is
>> necessary to make up the variance in utilization potential. There is
>> also the amortization required for lifetime use, etc. As stated, the
>> cost could go up a bit for less use, but since the overall frequency
>> exchanges are less, the overall cost is going to be less.
>> 
>> Film dosimeters have less to do with the inventory issue, but there
>> are other considerations as well that demonstrate why wearing a film
>> 4 times a year instead of 12 times a year, why the cost per period
>> isn't 1/3, as was suggested.
>> 
>> ------------------------------------------------------------------------
>> 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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