NAVI D-25 Instruction Manual page 58

ION electrode
Potassium
+
K
Calcium
2+
Ca
Chloride
-
Cl
Fluoride
-
F
Nitrate
-
NO
3
Ammonia
NH
3
D-52/53/54/55
Additives and pH range
Additives (per liter)
5.9 g/L sodium chloride
(NaCl)
7.5 g/L potassium
chloride (KCl)
10 g/L potassium sulfate
(KNO )
3
10 g/L potassium sulfate
(KNO )
3
No additives
4 g/L sodium hydroxide
(NaOH)
③ Sample measuring environment
A potential slope measured using an ION electrode
follows Nernst's equation (see page 186) and is affected
by the solution being measured. Also, if the solution is
not mixed well enough, the response becomes slow,
rendering it impossible to measure low concentrations
and causing inconsistent measurements. Calibration
with standard solution and measurement of the sample
should be performed using a temperature bath and while
stirring the solutions.
④ Effects of interfering ions on sample
If the sample cannot be measured properly even after
taking the preventative measures described in items 1
through 3, the solution may contain interfering ions.
2 Taking Measurements
2.7 Ion measurement (D-53)
pH range
pH 5 – 11
(Ideal is near neutral)
pH 5 – 11
(Ideal is near neutral)
pH 3 – 11
(Ideal is near neutral)
pH 4 – 10
pH 3 – 7
pH 12 or higher
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