[volt-nuts] Fluke 731B

Bill Gold wpgold3637 at att.net
Sat Mar 21 19:54:38 EDT 2015


    I have one 731B that I have had for 15 or more years.  I have only been
plotting drift for the last 10 years.  This was done against a bank of four
732A references.  The maximum drift that I have observed is about -1.5 ppm
over that 10 year period.  This is as best as I can determine without having
a Josephson Junction Array.  During the first 5 years of that period it
seemed to drift around +0.4 ppm total, but then in December 2010 I moved to
a new home and at that time it seems to have a -1.5ppm total drift over the
next 5 years.  Not too sure why.  So as far as yearly drift I guess you
could say that it averages around -0.15 ppm per year over that 10 year
period.  As far as temperature dependence, all of this is over a range of
20C to 24C depending upon the temperature of the room.  I cannot separate
the temp variations from the DC noise but just a casual look at the chart
for the past 6 years it seems to indicate that this 731B output goes down
with a higher room temp and vice versa but less than 0.4 ppm total over that
range of temps.

    Does this one beat specs, you bet!  Others may not be this good however.


----- Original Message ----- 
From: "Richard Moore" <richiem5683 at gmail.com>
To: <volt-nuts at febo.com>
Sent: Saturday, March 21, 2015 1:02 PM
Subject: [volt-nuts] Fluke 731B

> Hi all — realisitcally, what sort of stability can be expected from a
fully functional 731B regarding variation in ambient temp a few degrees C
around 23, and for long-term drift?
> Fluke’s specs are very conservative, and I think the 731 is far better
than the specs would lead you to believe, but I have no practical experience
with these units.
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