NAVI D-25, Инструкция по эксплуатации

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7 Reference
7.4 Conductivity measurement
D-52/53/54/55 193
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New units (SI units)
New measurement units, called SI units, have come into
use in recent years. Accordingly, the meter also uses SI
units. The following conversion table is provided for
people who are used to using the conventional kind of
conductivity meter. Note that along with the change in
unit systems, the measurement values and cell counts
have also changed.
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Temperature compensation
The conductivity of a solution generally varies greatly,
depending on the temperature of the solution. Because
the conductivity of a solution is based on its ION
conductivity, as explained above, the higher the
temperature of the solution the more active its ions and
the higher its conductivity. Using a given temperature as
the standard (and calling that the standard temperature),
the “temperature coefficient” expresses how much
change (expressed in %) occurs in conductivity when
the temperature of the solution changes by 1ºC. The
temperature coefficient is expressed in units of “%/ºC
(standard temperature).” This temperature coefficient is
found by assuming that the conductivity of the sample
changes linearly in relation to temperature, whereas the
change in conductivity of an actual sample, strictly
speaking, follows a curve. The shape of this curve
changes, depending on the kind of sample being
measured. Most solutions, however, are said to
generally have a temperature coefficient of 2%/ºC (25ºC
Former
units
⇒ SI units
Cell constant
1 cm
-1 ⇒
100 m
-1
0.1 cm
-1
⇒
10 m
-1
10 cm
-1 ⇒
1000 m
-1
Measurement
value 10
µ
S/cm ⇒ 1 mS/m
1 mS/cm ⇒ 100 mS/m
100 mS/cm ⇒ 10 S/m