Survey Meter Response Time - 2

["radbuster" <radbuster@netzero.net>]

Regarding yesterday's post on this subject, I went back and looked at
Cember's HP textbook.  (Am I the only one who forgets this stuff???)  The
response time is a function of the RC time constant.  The equation is:

f (fraction of final reading) = 1 - exp-(t/RC)

where exp is "e to the..."  So all you need is the instrument time
constant--not so easy to get.  Thanks to Raleigh at Ludlum, I got the time
constant for the Model 9, on x10 scale, is 1.8 sec.  So in 2 seconds I got
81% of the final reading.

Joel I. Cehn, CHP
cehn@aol.com

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