MicroR inst, NaI question

[Les Slaback <lester.slaback@nist.gov>]

Not mentioned so far, albeit on the expensive side, are ....
The portable Exploranium NaI unit that uses an algorithm to give a good
energy compensated dose rate response, plus displays a spectrum.   - $6k

The Scintrex unit (hope I remembered the company right) that uses a large
plastic scintillator (hence more sensitive than the Bicron) and has a
algorithm to distinguish non-natural sources (uses an energy window).
Pretty neat.   -$7k  ?

And the multitude of truly portable MCAs these days, e.g., HPI's, Oxford's
instruments.

Question:  What is the change in the NaI PM technology that has reduced the
power draw so much that these portable MCAs work on just a few batteries?
It used to be that you needed a separate, wieghty battery pack.
Disclaimer:  the above are the personal musings of the author, and do not
represent any past, present, or future position of NIST, the U.S. government,
or anyone else who might think that they are in a position of authority. 
Lester Slaback, Jr.  [Lester.Slaback@NIST.GOV] 
NBSR Health Physics 
Center for Neutron Research 
NIST 
Gaithersburg, MD  20899 
301 975-5810