5 | Measurement Basics
G 1400 series
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B-H87.0.0X.DK2-3.0
5
Measurement Basics
5.1
Conductivity principles
Conductivity γ
Conductivity describes the capability of a material to conduct electrical current. It is
also the inverse of specific resistance. The conductance is the inverse of the measured
resistance R.
Formula:
γ = l / (R*A)
l = length of the material
A = cross section
R = measured resistance
Unit [γ] = Siemens / metre = S / m
Normally, the values for liquids are specified in µS/cm or in mS/cm
5.2
General information about conductivity measuring
During the measurement, the conductivity measuring cell must be dipped at least in so
far, that at least 30 mm (G 1420: 25 mm) beginning from the top of the measuring cell,
is located in the medium. The maximum immersion depth for continuous operation
should not exceed 110 mm (G 1420: 70 mm)
Illustration: Measuring cell G 1410
The measuring cell can either be stored dry or in water. After dry storage wetting time
will be prolonged slightly. If changing over from one liquid to another with conductivities
varying widely make sure to properly rinse and shake dry measuring cell.
If conductivity measured is much higher or lower than expected this may be due to the
electrode being soiled with non-conducting or conducting foreign materials. Measuring
cell has to be cleaned with a watery soap solution. When measuring media with low
conductivities the electrode has to be stirred sufficiently.
CAUTION
Measuring cell must never come into contact with water-repellent materials such as oil
or silicone.
Recommended immersion depth
