Hello Roger, I made 2 calibration solutions. I first used the supplied calibration solution to calibrate my meter. Then I mixed my solutions and tested them. This gives me a primary calibration, and two secondary check points.
I put 1 ml of PH 7 test solution in 499 ml of my tap water. This gives me 123 uS. I then put 1 ml of PH 7 test solution in 499 ml of distilled water. This gives me 30 uS. Since I use PH meters a lot, I have a lot of the test solutions and keep them fresh. I don't know if the conductivity will vary from batch to batch, but I will have to go through a liter of my test solution before I will find out. Tom ----- Original Message ----- From: "Roger Barker" <[email protected]> To: <[email protected]> Sent: Sunday, April 18, 2010 7:36 PM Subject: Re: CS>YO YO EIS > Just as a matter of interest. Does anyone know how to make/mix the > calibration solution for a pH meter? > > Cheers, Roger B > NZ > > > On 19/04/2010, at 2:24 PM, poast wrote: > > > Hello Malcolm, > > > > While I totally agree with you, it is just too much fun to simply > > stop. > > This batch will be played with to death and never consumed. > > > > The saga continues. > > > > I decided to add some baking soda to the solution to balance the > > PH. The PH > > had dropped to about 3 and I brought it back up to 6.8. > > > > Next I added some ascorbic acid and it turned brown, then almost > > immediately > > turned clear again. I added more and the same thing happened. > > More is > > added and the same thing happens again. > > > > Finally I ended up with a gray layer at the bottom of the jar, but > > the rest > > of the solution is clear. I just shook it up to see what happens. > > > > The PH is now back to 4.6. Very interesting stuff. I hold it up > > to the > > light with the sun at my back and it looks bluish gray. When I > > turn around > > and look at the sun through the solution it looks dark amber. > > > > I find it interesting that I still have a great Tyndal effect and > > that the > > solution is staying clear. > > > > Oh well, I will exercise (or as Dok commented exOrcise) it a few > > more times > > and see what happens. > > > > Thanks for your help in trying to figure this out. > > > > Tom > > > > > -- > The Silver List is a moderated forum for discussing Colloidal Silver. > Rules and Instructions: http://www.silverlist.org > > Unsubscribe: > <mailto:[email protected]?subject=unsubscribe> > Archives: > http://www.mail-archive.com/[email protected]/maillist.html > > Off-Topic discussions: <mailto:[email protected]> > List Owner: Mike Devour <mailto:[email protected]> >
