21
pH BUFFER TEMPERA
TURE DEPENDENCE
The temperature has an effect on pH. The calibration buffer solutions are affected by temperature
changes to a lesser degree than normal solutions. During calibration the instrument will
automatically calibrate to the pH value corresponding to the measured temperature.
TEMP
pH BUFFERS
°C °F 1.68 4.01 6.86 7.01 9.18 10.01 12.45
0
32 1.67 4.01 6.98 7.13 9.46 10.32 10.38
5
41 1.67 4.00 6.95 7.10 9.39 10.25 13.18
10 50 1.67 4.00 6.92 7.07 9.33 10.18 12.99
15 59 1.67 4.00 6.90 7.05 9.27 10.12 12.80
20 68 1.68 4.00 6.88 7.03 9.22 10.06 12.62
25 77 1.68 4.01 6.86 7.01 9.18 10.01 12.45
30 86 1.68 4.02 6.85 7.00 9.14 9.96 12.29
35 95 1.69 4.03 6.84 6.99 9.11 9.92 12.13
40 104 1.69 4.04 6.84 6.98 9.07 9.88 11.98
45 113 1.70 4.05 6.83 6.98 9.04 9.85 11.83
50 122 1.71 4.06 6.83 6.98 9.01 9.82 11.70
55 131 1.72 4.08 6.84 6.98 8.99 9.79 11.57
60 140 1.72 4.09 6.84 6.98 8.97 9.77 11.44
65 149 1.73 4.11 6.84 6.99 8.95 9.76 11.32
70 158 1.74 4.12 6.85 6.99 8.93 9.75 11.21
75 167 1.76 4.14 6.86 7.00 8.91 9.74 11.10
80 176 1.77 4.16 6.87 7.01 8.89 9.74 11.00
85 185 1.78 4.17 6.87 7.02 8.87 9.74 10.91
90 194 1.79 4.19 6.88 7.03 8.85 9.75 10.82
95 203 1.81 4.20 6.89 7.04 8.83 9.76 10.73
During calibration the instrument will display the pH buffer value at 25 °C.