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RE: Radium on Luminous Dial Watches



Date: Wed, 14 Nov 2001 08:41:44 -0500

From: "Kolb, William (WKOLB)" <WKOLB@arinc.com>

Subject: RE: Radium on Luminous Dial Watches



Here are some measurements made with the S.E. International, Inc. Inspector

GM counter that are traceable to radium standards. A log-log calibration

plot of CPM Vs four radium standards ranging from  0.0001 to 0.1 uCi was

used to estimate the radium content. The same geometry was maintained

throughout. All measurements were made without watch crystals and, most

cases, the dial face alone was measured. I have no idea when any of these

watches were made. 



For comparison, the 0.01 uCi Ra standard reads about 4.4 mR/hr against the

ion chamber window of a Victoreen 440RF/D meter. The  0.1 uCi Ra standard

reads about 36 mR/hr. The hottest of these watch dials reads about 40 mR/hr

when placed directly against the chamber window. Mileage obviously varies.



Name            Configuration    Radium (uCi)



Lucerne           dial            0.0053

Tudor Oyster      dial            0.0061

The Bell          dial            0.0063

Milus             dial            0.0071

Benrus            dial            0.019

Cyma              dial            0.039

Hamilton          dial            0.047

Nivia             dial            0.052

Witnauer          dial + hands    0.053

Illinois          dial + hands    0.066

Rolex             dial            0.091

Ord. Dept. USA    dial + hands    0.099

Bulova            dial            0.12



bill

WM Kolb

ARINC

410-266-4017



-----Original Message-----

From: Otto G. Raabe [mailto:ograabe@UCDAVIS.EDU]

Sent: Monday, November 12, 2001 8:12 PM

To: RADSAFE Listserver

Subject: Re: Radium on Luminous Dial Watches



November 12, 2001

Davis, CA



My inquiry about the quantity of radium on the dial of

pre-1950 luminous

dial watches resulted in replies that covered the range from

0.01

microcuries to 15 microcuries. 



SNIP



I thank all those of you who responded. 

The radium dial watches were manufactured primarily before

1950. If any of

you have one of these watches and a calibrated counting

system, please make

a measurement and let us know what you find. To find one of

these watch,

such as the famous Elgin radium dial watches, check out

E-Bay or

http://members.aol.com/vwws/vwws.html



Sincerely,



Otto



**********************************************

Prof. Otto G. Raabe, Ph.D., CHP

Center for Health & the Environment

(Street Address: Bldg. 3792, Old Davis Road) 

University of California, Davis, CA 95616

E-Mail: ograabe@ucdavis.edu

Phone: (530) 752-7754   FAX: (530) 758-6140

***********************************************



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