NAVI D-25, Instruction Manual

Page: 59 / 227

2 Taking Measurements
2.7 Ion measurement (D-53)
48 HORIBA
Effects of interfering ions
Measurements cannot be made when the compatible
tolerance limit multiplied by the concentration of the ions
to be measured is greater than the compatible ION
concentration.
ION
electrode
Compatible tolerance limits
Potassium
K
+
Li
+
, Ma
+
, Mg
2+
, Ca
2+
, Sr
2+
, Ba
2+
= 1,000;
NH
4
+
= 70; Cs
+
= 3; Rb
+
= 0.4
(at 10
-4
mol/L K
+
)
Calcium
Ca
2+
Na
+
, K
+
, Ba
2+
, NH
4
+
, Mg
2+
= 1,000; Mn
2+
=
500; Co
2+
= 350; Ni
4+
, Cu
2+
= 70; Sr
2+
= 50;
Fe
2+
, Zn
2+
= 1; Fe
3+
= 0.1
(at 10
-4
mol/L Ca
2+
)
Chloride
Cl
-
NO
3
-
, F
-
, HCO
3
-
, SO
4
2-
, PO
4
2-
= 1000;
SCN
-
= 0.3; MnO
4
-
= 0.1; Br
-
= 0.03;
S
2
O
3
2-
, S
2-
, I
-
, Ag
+
, Hg
2+
= not possible
(at 10
-3
mol/L Cl
-
)
Fluoride
F
-
OH
-
= 10 (within measurable range)
Nitrate
NO
3
-
SO
4
2-
= 1000; CH
3
COO
-
= 300; F
-
= 200;
Cl
-
= 40; NO
2
-
= 3; I
-
= 0.1; ClO
4
-
= 0.03;
Br
-
= 2
(at 10
-3
mol/L NO
3
-
)
Ammonia
NH
3
Volatile amino (within measurable range)