[ RadSafe ] RE: Exploranium GR-135 question

[Clark Barton]

I have some experience with the GR-135.  It was by far the best field gamma
spec unit I have used or had on demo.  I had the version that is NaI and GM
only, and I don't think I ever had it in a field high enough to use the GM
for dose rate, but since I got the unit for the NaI features, I didn't care
to test the GM dose functions.  The gamma spec functions and built in
identification work very well, especially if you have a simple spectrum.  On
complex spectra, all of the normal limitations of a NaI based system are
still there, and cause all the normal problems.  When we used it for more
than a quick look, we would download the spectra to a computer and manually
ID all the obvious peaks.  The on-board ID function is the best I've used in
the field, but manual ID can refine the list somewhat.

 

All in all, I like the unit very much, and would not hesitate to get one for
a project where we needed the capability to field ID, or sometimes more
importantly rule out certain nuclides in the field.  If I expected to always
have complex spectra, then it might not be the right choice, but it would be
my number one choice for a field NaI spectroscopy unit.

 

Clark Barton, CHP