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From: anachem@silver.ucs.indiana.edu (mark gilstrap)
Subject: Re: How to measure/detect X-ray (cheap)?
Message-ID: <1991May2.205942.7194@bronze.ucs.indiana.edu>
Keywords: personal dosimetry, film, TLD
Sender: news@bronze.ucs.indiana.edu (USENET News System)
Organization: Indiana University, Bloomington
References: <4212786@harvee.UUCP> <1991May1.161415.4235@swbatl.sbc.com> <4916@kitty.UUCP>
Date: Thu, 2 May 91 20:59:42 GMT
Lines: 51

In article <4916@kitty.UUCP> larry@kitty.UUCP (Larry Lippman) writes:
>In article <1991May1.161415.4235@swbatl.sbc.com> ken@swbatl.sbc.com (Ken Gianino 5-9081) writes:
>>>I would not trust film badge dosimeters.  My wife works for a vet and
>>>they use film badge dosimeters in their x-ray room.  One of her co-workers
>>>decieded to "test" the dosimeter by giving it a full dose of x-rays
>>
>> Does anyone still use film badges?
>
>	Sure!
>
		Here at IU too.

>> I thought the whole industry switched
>> over to thermoluminescent dosimeters years ago.  They look like film badges.
>
>	Film badges, which typically use the dual-emulsion Kodak Type 2
>Personal Monitoring Film, are useful for estimating the energy distribution
>of absorbed radiation since they generally mask the film with four filter
>quadrants.  Film badge operation and processing cost is also somewhat less
>than that of TLD.
>
		The masks help discern accidental film fogging
		from real exposures. Unfortunately it costs 
		extra to have a human look for a pattern on the
		film vs the automatic densitometer readings. My
		experience with IU is that a reading is always
		considered to be an accident. "you might have
		left it clipped to a lamp or in a window or on
		a heat register" and never is the human eye and
		associated expense authorized. So we never know.
		We have to go by cumulative totals correlated 
		to work location - e.g the old GE xrd/xrf is a hot
		place. Even though an electronic's technician can
		"see" the x-rays out in the hallway with a detector
		tube as he passes the doorway, the IU rad safety
		screenings never see anything....  

		I know of cases where students wanted to test the
		system and intentionally exposed film badges. Never
		a word....  The only action we get is when someone
		gets a burn from one of the stuck interlocks etc...
		Somehow IU finagled a self policing agreement. If
		you try to go to OSHA with it - well IU has an OSHA
		man right here in his own office on campus. He was
		a footbal star...took IU to the Rose Bowl a few
		decades back...doesn't know where to look when you
		ask him for the wording of a regulation...  but I
		digress.