Xref: utzoo rec.radio.amateur.misc:2120 sci.electronics:19693
Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!ub!kitty!larry
From: larry@kitty.UUCP (Larry Lippman)
Newsgroups: rec.radio.amateur.misc,sci.electronics
Subject: Re: How to measure/detect X-ray (cheap)?
Summary: Film badge dosimeters
Keywords: film badge dosimeters
Message-ID: <4911@kitty.UUCP>
Date: 28 Apr 91 16:10:21 GMT
References: <1991Apr23.172122.13076@Informatik.TU-Muenchen.DE> <4902@kitty.UUCP> <4212786@harvee.UUCP>
Followup-To: rec.radio.amateur.misc,sci.electronics
Organization: Recognition Research Corp., Clarence, NY
Lines: 30

>> 	My best suggestion, if you are really concerned, is to obtain a
>> photographic film badge dosimeter, fasten it to the outside of the device
>> in question, run the device for several hours, and then have the film
>> badge developed and evaluated with a densitometer.
>
>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
>i.e the badge was the x-ray target.  The report on the badge gave no
>indication that the badge had been exposed.

	Film badge dosimeters *DO* work!  After all, how are x-rays most
commonly taken, if not by means of exposing photographic film?

	I suspect the incident you related is isolated, and (hopefully)
very uncommon.  It's obvious that the organization processing the dosimeter
film made some error.

>Now, I don't know what
>the detection threshold is or if the badge readers can tell the
>difference between types of exposure but I don't have much faith
>in dosimeters anymore.

	Good quality film badges have multiple filters covering portions
of the film.  Such filters permit bracketing of exposure into energy levels
between 0.030 and 1.5 or so MeV.

Larry Lippman @ Recognition Research Corp.  "Have you hugged your cat today?"
VOICE: 716/688-1231       {boulder, rutgers, watmath}!ub!kitty!larry
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