ec/pH meters

[Marty Reichenberger <mreich@terraworld.net>]

Since we are discussing soil testing meters, I have a question for those
who use the Myron AG-5 EC/pH meters.  We use a 2:1 distilled water to
soil ratio, let the solution stand for 12 hours, decant off the solution
and test it.  The results of the EC are, let's say 1.3.  If we send the
same sample to a lab, Ohio State, the reading they are getting is
approximately 2.5.  Is anyone else noticing that much difference in the
EC readings?  The pH agrees with Ohio State 100%.  I have calibrated the
meter with the solution supplied, and the meter is nearly new.  I also
spoke with the company and they told me that if the calibration solution
was reading correctly, then the meter was working.  Any ideas of the
problem we are having?  We have let the solution stand for 15 minutes to
24 hours and the EC reading increases, but never near laboratory
values.  I am also extremely careful in the prep of the solution being
tested.  Any ideas to help would be appreciated!!!!!

Thank you,
Marty Reichenberger
Green Thumb Greenhouse
Independence, KS