not much to comment on, after all how exciting can a calibration solution be? I will use this to calibrate my pH meter about once per month and use it to measure the wort in homebrew. I have found that calculations from Bru'in Water are pretty accurate so just use this to confirm and to adjust for future predictions. Darker malts generally go a little lower than predicted and lighter malts a little higher.  Since a lot of the mashing completes pretty rapidly, adjusting the wort after the fact is less useful.