ionization chambers, micro rem meters, etc.

[Jennifer Wilson <wilsonj@unbc.edu>]

I am in a quandry as to what survey meter is appropriate for my needs.  I 
need to be able to assess accurately fields as low as 2.5 microsieverts/h 
(0.25 mrem/h).  The radionuclides we work with are low energy gamma/x-ray 
emitters, a wide range of energies of beta emitters and some higher 
energy gamma emitters.  I have been looking at ionization chambers, both 
pressurized and not, as well as micro rem/ micro sievert meters.  [The 2.5 
microsievert/h limit is the maximum field strength allowable for an area 
where non-ARWs work(AECB).]  I already have a Ludlum LEGs detector and thin 
end window GM detector.  Can any one tell me what they use and which 
instruments serve them best for assessing field strengths?  I am leaning 
towards a Victoreen 450P or 450CHP.  Any feedback on these instruments?

Thank you for any assistance you can provide.

				Sincerely,

				Jennifer Wilson
				University of Northern B.C.