Horiba Scientific 6560S-10C, Instruction Manual

Page: 78 / 85

66

About interfering ions in Cl
-
concentration
measurement
Since a complex is formed on the surface of the electrode in a solution
containing S
2
O
3
2-
, S
2-
, l
-
, Ag
+
, and Hg
2+
, measurement cannot be
performed.

Response time
The response times of ion selective electrodes differ depending on factors
such as the type and structure of the electrode, and type and concentration
of ions.
In general, the response time tends to be shorter when the ion
concentration is high and longer when the ion concentration is low.
Furthermore, the response time may become shorter when a high
concentration solution is measured after measuring a low concentration
solution, while the opposite case may cause the response time to become
longer.
The time required to reach a reading value that is 95% stabilized is within
30 seconds approximately in the case of a standard solution with a
concentration ranging from 10 mg/L to 100 mg/L.

Impact of light
With some types of ion selective electrodes (e.g. non-crystalline solid
membrane electrodes), light may have an impact that causes the
electromotive force to change.
If you will use one of these types, it is not desirable to take measurements
in a place exposed to strong light or where the luminous intensity changes.
When using such an electrode, avoid the exposure of the light by, for
example, using a brown beaker.
Generally, electrodes with the ion selective membrane whose main
component is silver halide, such as CI
-
, Br
-
, I
-
, CN
-
, may receive the impact
of the light.