Thermo Scientific 9101BN, Руководство пользователя

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7 Refillable Ag/AgCl pH Electrode User Guide
Interferences
Sodium ions are the principal interference of the pH electrode
and cause increasing error at higher pH (lower hydrogen
ion activities) and at higher temperatures. Because the pH
membrane is composed of special low sodium error glass, error
due to sodium is negligible when measuring at pH values less
than 12. When measuring at pH values greater than 12, add the
correction value from the nomograph below to the observed
pH reading.
10
11
12
13
80
70
60
50
40
30
°
C 20 0.1 M
25
0.5 M
1 M
2 M
5 M
5 M
0.5 M
0.1 M
1 M
2 M
20 ° C
25
30
40
50
60
70
80
0.70
0.60
0.50
0.40
0.30
0.25
0.20
0.15
0.10
0.08
0.06
0.05
0.04
0.03
0.02
0.01
0.005
pH correction
to be added
Sample
pH reading
sample
sodium
concentration
Typical Sodium Error
Example:
pH reading 12.10
Sodium concentration 0.5 M
Temperature 50 °C
Correction 0.01
Corrected pH reading 12.11