Date: Mon, 20 Jan 1997 14:05:31 -0600 (CST) From: burkhard@aries.scs.uiuc.edu To: cp@opus.hpl.hp.com Message-Id: <aabcdefg283$foo@default> Subject: Re: cheap pH meters
Hello Rick,
> It has been my experience that those cheap pH meters sold in garden
> centers (about $20 US) are really worthless crap. I would get wildly
> fluctuating readings on the same sand/peat mix all the time. I
> somtimes would get pH's of 9 or 10 in pure distilled water. I also
> got basic reading from tomato juice which is acidic. IMHO if you are
> serious about measuring Ph you need a real lab grade pH meter.
> However, these are expensive.
>
I was wondering if your garden pH meter was calibrated. That might
explain the radical readings. If the meter is adjustable, just make up
some buffer solutions of different acidity and calibrate your meter,
using pure water as your standard. Also, rinsing of the meter and
adjusting the reading back to pH of 7 in water before each sampling
might also help. Good luck.
Paul Burkhardt
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