info on measuring pH in DI water

[DJ88]

I haven't quite figured it all out.. all I know is that everytime I read about the H+ wih reference to a pH probe I keep getting the same thing. It measures the activity of the H+ ions or lack there of. It does make sense to me WRT the potential created between the two probes. Luckily I just did a lab in my physics course which created a similar voltage potential to measure heat transfer.

[StirCrazy]

hey Brad from what I learned in water quality (we are very concerend about the ph and the desolved minerals in our boilers) blowing a tube at 650psi and 800 degrees isn't something I want to see again [img]images/smiles/icon_biggrin.gif[/img]

Pure water is a PH of 7.0 when we distill our sea water we end up with a water that is 7.0 PH and less than 0.065epm. electrical ph testers and other testers such as hardness. need *stuff* in the water to be able to have a current pass from electrode to electrode. absolutly Pure water will not conduct electricity very well but the slightest bit of contamanants and it will flow. so sence the PH meters operate on detecting free H ions when the # of the H ions fall below a certian threshole you will get errors as the electrical signal will not be strong enuf to remain constant. to show another example of this we went out a bought way expensive lab grade test meters for doing our water tests on the ship but everyone was always getting reading that were out to lunch and then when done by titrating acids and such the #'s were always constant. this was because our water requirments for the boilers was to *pure* for the meters to work corectly, so instead of being done water tests in 5 minites is back to the old 1 hour [img]images/smiles/icon_smile.gif[/img]

oh on another note I broke a small piece off that sheet I was talking to yyou on the phone about.. how do I tell if it is what we want or not? or can you tell by looking at it? if so are you going to hillside tomorrow? I have to go to kitchen craft but I couldmeat you somewhare with the sample.

Steve

[ 15 January 2002: Message edited by: StirCrazy ]