Description
A pH buffer solution is used to check that your pH meter or electrode is calibrated and to ensure that it is working correctly.
The three most common pH buffer solutions are pH4 (red), pH7 (green) and pH10 (blue).
If you are operating in the acidic range, then you will calibrate with pH7 and then pH4, and if operating an Alkaline range, then you would calibrate with pH7 and then pH10.
The solution should not be used if it passed its expiry date, as your results may not be accurate.
Store pH buffer solutions in their original containers in a cool, dry place and protected from direct sunlight.