Re: [Killietalk] pH (was Re: copper leaching from new plumbing)

[Fred Behrmann <athensaquatics at juno_com>]

Hi Guys, Pocket digital pH meters are a pain in the ass. Even worse is a
pocket digital TDS meter. For $5 you can buy enough pH reagent for 250
titration tests. If it takes you more than 60 seconds to do it; you are
just too slow. If you have soft water to start with and switch fish to
newly  set up tanks once a month; you don't need a hardness test kit.    
                                                      On Fri, 16 Feb 2007
07:48:50 EST LeeH920226 at aol_com writes:
> 
> In a message dated 2/16/07 1:11:34 AM, whuntley at verizon_net writes:
> 
> << 
> You might just have a very poor or damaged meter, Lee.
> 
>  >>
> 
> Wright,
>     I was a technical leader of a study at DuPont which ran an 
> experiment 
> with a group of trained laboratory technicians to determine the 
> sources of error 
> in pH measurements. They each measured samples we provided them and 
> used their 
> own pH meters in the manner they normally used them. Results were 
> dramatic. 
> Unless they calibrated the meter just before using them, the results 
> were all 
> over the map. These were with mostly laboratory bench model pH 
> meters -- all 
> fairly expensive from reputable manufacturers. Only those who 
> calibrated the 
> meter before the test gave results close to the right value. These 
> test solutions 
> were buffered solutions. Calibrating once a day was not sufficient 
> either. 
> Storing the electrode in pH 4 buffer is also important. Try checking 
> your meter 
> and see. I know my pH meters, I have two, are the same way. TDS 
> meters on the 
> other hand never seem to drift, unless the batteries are run down.
> 
> Lee Harper
> Media, PA
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> 
 
 
Sincerely,
Fred Behrmann
Athens Aquatics
37 W. Bridge Street
Catskill, NY 12414    Phone:(518) 943-2630
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