Appendix 3 for isc (inductive conductivity), L configure, App.3-1 – Yokogawa 2-Wire Dual Channel Transmitter/Analyzer FLXA21 User Manual
Page 229: Ntemperature compensation, App. isc, Lnacl (standard temperature compensation), Ltemperature compensation coefficient (tc)
<Appendix 3 For ISC (Inductive Conductivity)>
App.3-1
IM 12A01A02-01E
5th Edition : Oct. 31, 2013-00
Appendix 3 For ISC (Inductive Conductivity)
n
Temperature compensation
The conductivity of a solution is very dependent on temperature. Typically for every 1°C
change in temperature the solution conductivity will change by approximately 2%. The effect of
temperature varies from one solution to another and is determined by several factors like solution
composition, concentration and temperature range. A coefficient (α) is introduced to express the
amount of temperature influence in % change in conductivity/°C. In almost all applications this
temperature influence must be compensated before the conductivity reading can be interpreted
as an accurate measure of concentration or purity.
l
NaCl (standard temperature compensation)
The FLXA21 has the default temperature compensation function based on a sodium chloride
(NaCl) solution. This function can be used for various applications and is compatible with the
NaCl compensation function of typical laboratory or portable instruments.
Table 1 NaCl compensation according to IEC 60746-3 with Tref. = 25°C
Temperature
(°C)
Ratio* Temperature compensa-
tion coefficient (%/°C)
Temperature
(°C)
Ratio* Temperature compensa-
tion coefficient (%/°C)
0
0.54
1.8
100
2.68
2.2
10
0.72
1.9
110
2.90
2.2
20
0.90
2.0
120
3.12
2.2
25
1.00
—
130
3.34
2.2
30
1.10
2.0
140
3.56
2.2
40
1.31
2.0
150
3.79
2.2
50
1.53
2.1
160
4.03
2.2
60
1.76
2.2
170
4.23
2.2
70
1.99
2.2
180
4.42
2.2
80
2.22
2.2
190
4.61
2.2
90
2.45
2.2
200
4.78
2.2
*:
The ratio of the conductivity at respective temperatures to the conductivity at the reference temperature.
l
Temperature compensation coefficient (TC)
Set the temperature compensation coefficient based on the degree of influence of temperature
on the conductivity (%/°C).
If the temperature compensation coefficient of the sample solution is known from laboratory
experiments or has been previously determined, enter the value.
The setting range is between 0.00 and 10.0%. By combining with the reference temperature
setting, a linear compensation function can be obtained. This is applicable to all kinds of chemical
solution.
<Configure calculated temperature coefficient (TC).>
Follow routing
Commissioning >> Measurement setup >> Temp.compensation >> T.C.
Enter the temperature coefficient calculated from the following formula:
App.
ISC