User Guide

40
Typical Electrode Life
Ambient Temperature 1- 3 years
90 °C Less than 4 months
120°C Less than 1 month
High concentrations of sodium ions interfere
with readings in alkaline solutions; the pH at
which the interference starts to be significant
depends upon the composition of the glass.
This interference is the alkaline error and causes
the pH to be underestimated. Hanna's glass
formulations have the indicated characteristics.
Alkaline Error
1.0 Mol L
-1
Na
+
0.1 Mol L
-1
Na
+
Sodium Ion Correction for the Glass
at 20-25°C
Concentration pH Error
13.00
13.50
14.00
12.50
13.00
13.50
14.00
0.10
0.14
0.20
0.10
0.18
0.29
0.40