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Reference, Questions and Help => Nuke Q&A => Instrument Q&A => Topic started by: radgal on Jun 22, 2005, 11:39

Title: What calibration sources do you use for dose rate instuments?
Post by: radgal on Jun 22, 2005, 11:39
What are the sources used out there to calibrate Beta/Gamma dose rate instuments?

Also what do you use for daily reponse checks, source and strength?

There are just to satisfy my curiosity what different places use.

Thanks
Title: Re: What calibration sources do you use for dose rate instuments?
Post by: jjordan on Jun 22, 2005, 02:45
We use the Shepard to calibrate with, and we also source check the Tele's and AMP 100-200's with it. For the RO's  we use a Sr 90  2.0 e +4 uCi source with differnt shields to source check on all scales. I don't know if you got to see it or used it when you were here at Brunswick.
JJ
Title: Re: What calibration sources do you use for dose rate instuments?
Post by: makua13 on Jun 22, 2005, 04:37
C137 and Tc99 are the standards used by most (power) plants, but depending on what you are looking for the source may change.
Title: Re: What calibration sources do you use for dose rate instuments?
Post by: SloGlo on Jun 22, 2005, 05:50
What are the sources used out there to calibrate Beta/Gamma dose rate instuments?

Also what do you use for daily reponse checks, source and strength?

There are just to satisfy my curiosity what different places use.

Thanks
i've used cs137, tc99 most often, usually due to it's long life yielding less frequent t1/2 calcs.  on rare sites, i've used co60.
most are small content, 0.05 mci or so.  some have been bigger.  most are ~1" dia, but there have been rare times when bigger (~2") where on the site.
Title: Re: What calibration sources do you use for dose rate instuments?
Post by: radgal on Jun 23, 2005, 09:50
SloGlo, Makua13 and JJordon

Thanks for the replies.  This is what I thought you guys used.  I just looking for confirmation 

JJordon:  Do you have a Beta correction factor for your RO20 due to your calabration source being a really strong Beta emitter.  (According to Eberline the RO20 is 93% efficienct for SR90 but only 30% efficient for Uranium Slab detection.)  I believe I know the answer but since I worked there before but I would just like it for the record, so to speak.
Title: Re: What calibration sources do you use for dose rate instuments?
Post by: jjordan on Jun 23, 2005, 03:18
RadGal,
We calibrate with the Shepard, which is a Cs137 source. We source check with the Sr90 source, and after we source check, we response check with a button source in the Inst Issue room before use and it is also Cs137. Our Beta correction factors are the industry standard 4 and 8 (bagged) :-*
Title: Re: What calibration sources do you use for dose rate instuments?
Post by: spentfuel on Jul 22, 2005, 04:22
we also cal with shepherd with Cs-137 sources but we do a beta response (not cal) with a U-235/238 slab source and use a beta correction factor in the feild dependent upon the amount of poly used to protect the instrument.  no bag x4, one bag x5, two bags x6