30
CALIBRA
TION
9.2. pH BUFFER TEMPERATURE 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 or set 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
13.38
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 displays the pH buffer value at 25 °C.