Most modern pH meters are supplied with the facility for automatic buffer recognition. The manufacturer will have programmed in a pH versus temperature profile into memory for a specific type of buffer such as DIN or NIST (see table below)
| DIN 19266 Buffers @25°C | NIST Buffers @ 20°C |
| 1.679 ± 0.010 | 1.677 ± 0.010 |
| 3.776 ± 0.010 | 3.788 ± 0.010 |
| 4.005 ± 0.010 | 4.001 ± 0.010 |
| 6.865 ± .0.010 | 6.879 ± 0.010 |
| 7.413 ± 0.010 | 7.429 ± 0.010 |
| 9.180 ± 0.010 | 9.225 ± 0.010 |
| 10.012 ± 0.010 | 10.062 ± 0.010 |
| 12.454 ± 0.050 | 12.627 ± 0.050 |
If a different buffer to that specified by the manufacturer is used for calibration this will result in calibration errors. If you have any doubt on the best buffers to use for your pH meter then the Reagecon Technical Services team will be happy to advise you.
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