seanz2003:
did you know a borax solution can be used to calibrate near this range? It will produce a buffer solution of around pH 9.2, so this method requires a controller that will allow calibration using arbitrary buffers.That Sparkfun kit doesn't do that.
Because it already has set calibration points. 4.0, 7.0, and 10.0 are very commonly used and widely available buffer solutions. And at $25, the stamp is the cheapest I have found.
But he's only interested in the 10.0 range, the 4,0 and 7.0 is useless. Considering the OP is only interested in a small range of pH values, it would be cheaper to purchase a Ph probe, use a single-chip instrumentation amp and do the calibration on the Arduino itself. The pH 10 buffers don't keep very well as they absorb CO2 from the atmosphere.