PCM detector choices....

[Dave Brown <david.brown@nist.gov>]

I gather from the responses I received regarding detector selection for

PCMs, that no one really has a strong opinion either way.  The

choice between sealed or gas flow proportional detectors seems to be

independent of the operational use/experience with these

instruments.  Most responders  found the Radon rejection

capability of the gas flow detector units to be ineffective.  

The only selection factor on the side of the gas flow type was the cost

of tube repair and/or replacement.  This factor is obviously

dependent on the location and use of the monitor and the frequency of

failures or window punctures.  We have units of both type monitors

here and the need for tube replacement/repair in either unit have been

rare.  


Further input on this is welcomed, you may email me directly at,

david.brown@nist.gov.

Regards,

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Dave Brown, CHP
National Institute of Standards and Technology
100 Bureau Drive, Stop 3543
Bldg 235 Rm B104
Gaithersburg, MD  20899-3543

301-975-5810 - office
301-921-9847 - fax
david.brown@nist.gov
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