Try looking for Beckman Zeromatic model. Again the accuracy as someone mentioned is in the probe itself. Get your buffer solutions to calibrate and you're set.
When I was doing photo chemical analysis in the 80s under military spec requirements, we used Beckman pH meters as the standard. Lots of Beckman stuff on eBay cheap.
And, in best practice you leave them running all the time with the probe in a proper buffer solution.
Last edited by kreeger; 08-18-2012 at 11:23 AM. Click to view previous post history.