AWE Direct

AWE Instruments

pH Buffers


pH Buffer solutions are solutions made to a known pH value which are very stable and resist changes in that pH value when small quantities of either acid or alkali are added during use.
The most commonly used pH electrodes have an Eo of 7 pH which means they produce a zero electrical signal at 7.00 pH and a positive millivolt potential as thepH falls and a negative millivolt potential as the pH increases. The best way to standardize any pH instrument is by using a 7.00 pH buffer to set 7.00 pH the zero output of the electrode and either 4.00 or 9.00pH as the span depending upon whether the pH values you wish to measure are acidic or alkali.
If your pH values can be either acidic or alkali simply calibrate on one buffer say 4.00 pH and carry out a buffer check on the other buffer 9.00 pH.