RE: EPD's and RF

["Scott Stafford" <scott.stafford@sympatico.ca>]

John



There is definitely the possibility of RF interference on the Siemens MK I

dosimeters...and the standard result is a massive spike in dose rate.  Most

electronic dosimeters can be affected by RF interference..(ours are affected

by the RF generated by close proximity to welding).



The newer MK II models appear to be less susceptible to this effect.  It may

be possible to shield the unit from RFI but one must bear in mind that this

will also shield the Beta window, and thus you will lose the ability to

accurately collect skin dose information.





Scott Stafford, B.Sc.

Assistant Health Physicist

Ontario Power Generation

Pickering Nuclear Generation Station

scott.stafford@sympatico.ca

Cell Phone E-mail: scott.stafford@fido.ca







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

From: owner-radsafe@list.vanderbilt.edu

[mailto:owner-radsafe@list.vanderbilt.edu]On Behalf Of John R Laferriere

Sent: June 13, 2002 8:19 AM

To: radsafe@list.vanderbilt.edu

Subject: EPD's and RF





Hello Radsafers- We recently put an electronic dosimeter out in

the guard house at our site entrance for issuance to the fire

department when they respond to an alarm on site.  I just

checked it and found it was showing a large dose.  I read the

data log on the unit and the dose accumulated a chunk at a

time, at random hours of random days that don't correspond

to any production schedules.  My hunch is that the unit is

getting affected by RF from a walkie-talkie base station

at the guard house.  Two questions:



1. Does my theory sound reasonable?

2. Is there any way to protect the dosimeter from the RF?

An aluminized mylar bag, perhaps?



The unit in question is one of the older Siemens

EPD-2's.



Thanks for any assistance you can provide!



John Laferriere, CHP

BMS Medical Imaging

978 671-8316



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

You are currently subscribed to the Radsafe mailing list. To unsubscribe,

send an e-mail to Majordomo@list.vanderbilt.edu  Put the text "unsubscribe

radsafe" (no quote marks) in the body of the e-mail, with no subject line.

You can view the Radsafe archives at http://www.vanderbilt.edu/radsafe/





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

You are currently subscribed to the Radsafe mailing list. To unsubscribe,

send an e-mail to Majordomo@list.vanderbilt.edu  Put the text "unsubscribe

radsafe" (no quote marks) in the body of the e-mail, with no subject line.

You can view the Radsafe archives at http://www.vanderbilt.edu/radsafe/