Re: Use of OSL Dosimeters for Environmental Monitoring

["Sandy Perle" <sandyfl@earthlink.net>]

Chris Hofmeyr stated the following:

> MHO any device which needs processing at a distant
> location is at a disadvantage, as any 'in transit' corrections to the
> registered dose adds variance and therefore degrades the precision of
> results.

Hi Chris,

It was a pleasure seeing you again a few weeks ago. I enjoyed the 
dialogue.

First comment ... Since it appears that the Draft N13.29 Standard for 
Environmental Monitoring has been resurrected, the levels to be 
measured are similar to the N13.11 Standard, and do not even address 
environmental levels. 

Now let me address your comment:

(1) Any measuring device has to be assessed to ensure that what is 
intended to be measured, can be within the technical constraints of 
the device. Once that is done, then ..

(2) The attributes of the device must be assessed in order to 
determine the variables that cause error within the measurement 
obtained. In your example, transit dose is just one of many factors.

(3) The over-all measurement of uncertainty can be calculated and 
used to determine the effectiveness of the measurement.

(4) The issue you raise is one that really doesn't address a device, 
but rather an opinion on whether or not any device should be sent off 
for analysis. When considering this, one must also look at the risk 
of a reported response having some degree of variation. The real 
question is, how much error are you willing to live with? In any 
measurement of environmental background, how accurate and precise is 
any measuring device? Take a micro-R meter .. how accurate is its 
measurement? In my opinion, it is no better than, or no worse than 
any passive device. It too is only as good as its calibration, 
maintenance and, the knowledge of the individual using it.

In conclusion. any device, with all of the known factors that can be 
assessed, that have an affect on the measurement, should be capable 
of being used for environmental monitoring. The errors we're talking 
about are small. There is much evidence to support this. The risk of 
any error within the measurement should be of little consequence, and 
not be a concern to anyone.

Regards,

------------------------------------------------------------------------
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/capecanaveral/1205
ICN Worldwide Dosimetry Website: http://www.dosimetry.com

************************************************************************
The RADSAFE Frequently Asked Questions list, archives and subscription
information can be accessed at http://www.ehs.uiuc.edu/~rad/radsafe.html