Re: Swab Conversions

[Rahim Ghanooni <rahim@inav.net>]

Dave:

At 12:21 PM 2/19/97 -0600, you wrote:
>1.  Has anyone performed any test converting dpm on a swab (small wad of 
>cotton on a stick) used for example inside a pipe to dpm/100cm-sq?  What are 
>your ideas on determining the area of the swabbed section in a pipe when you 
>are taking it through a small drilled hole? 

        We spiked a cotton swab with Co-60, that is the most dominated
nuclide         at our site, then place the swab in the low background
counter,            determined the efficiency. We usually take few swab from
the workers nostrils          after welding and grinding. 

>2.  Is there any data out there that estimates the amount of expected airborne 
>activity when welding or cutting a pipe with internal and/or external 
>contamination.
>
        The air sample result is based on the amount of contamination on the
pipe, we have experience on the location of the pipe and amount of the
contamination. The result of the air sample is also based on arc welding, or
regular welding.