Re: Response of Pocket dosimeters

[TDC@ehssun.lbl.gov]

60 keV is a bit on the low side for a regular DRD - I recall a lower energy
spec of about 100 keV.  However, it is well within the range of the low
energy variety.

BUT the regular DRD should still be usable.

As you alluded to you DO have to be concerned that the DRD remains in
saturation - if your peak exposure rate exceeds about 10^4 R/hr you will
be out of saturation and underread with the typical DRD.

The best way to check this is to compare with a TLD - expecially if you can
do this in areas of different exposure rates - that way you can pretty much
tell where the DRD starts to fall off.

If the DRD does get out of saturation and you still MUST have a real time
active reading - then the only instrument that I can think of that has any
chance at all of holding saturation AND has usable sensitivity is the HPI
1030.  We use several of them here at LBNL just for that reason.

I would still back my measurements up with a non rate sensitive device -
like a TLD.

Ted de Castro
tdc@ehssun.lbl.gov
University of California Lawrence Berkeley Laboratory
Bldg 75B Rm 112A
Berkeley, CA 94720
(510) 486-5256
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