OHAUS STARTER 3100C - Appendix; Conductivity Standards; Examples of Temperature Coefficients (a-value); Conductivity to TDS Conversion Factors

EN-18 STARTER 3100C Bench Conductivity Meter
7 APPENDIX
7.1 Conductivity standards
T(°C)
10 μS/cm
84 μS/cm
1413 μS/cm
12.88 mS/cm
5
6.1 µS/cm
53 µS/cm
896 µS/cm
8.22 mS/cm
10
7.0 µS/cm
60 µS/cm
1020 µS/cm
9.33 mS/cm
15
8.0 µS/cm
68 µS/cm
1147 µS/cm
10.48 mS/cm
20
9.0 µS/cm
76 µS/cm
1278 µS/cm
11.67 mS/cm
25
10.0 µS/cm
84 µS/cm
1413 µS/cm
12.88 mS/cm
30
11.0 µS/cm
92 µS/cm
1552 µS/cm
14.12 mS/cm
35
12.1 µS/cm
101 µS/cm
1667 µS/cm
15.39 mS/cm
7.2 Examples of temperature coefficients (α-value)
Substance at 25 °C
Concentration [%]
Temperature coefficient α [%/°C]
HCl
10
1.56
KCl
10
1.88
CH3COOH
10
1.69
NaCl
10
2.14
H2SO4
10
1.28
HF
1.5
7.20
α-coefficients of conductivity standards for a calculation to reference temperature of 25°C
Standard
Measurement
temp.: 15°C
Measurement
temp.: 20°C
Measurement
temp.: 30°C
Measurement
temp.: 35°C
84 μS/cm
1.95
1.95
1.95
2.01
1413 μS/cm
1.94
1.94
1.94
1.99
12.88 mS/cm
1.90
1.89
1.91
1.95
7.3 Conductivity to TDS conversion factors
Conductivity
At 25 °C
TDS KCl
TDS NaCl
ppm value
Factor
ppm value
Factor
84 μS
40.38
0.5048
38.04
0.4755
447 μS
225.6
0.5047
215.5
0.4822
1413 μS
744.7
0.527
702.1
0.4969
1500 μS
757.1
0.5047
737.1
0.4914
8974 μS
5101
0.5685
4487
0.5000
12.88 μS
7447
0.5782
7230
0.5613
15 μS
8759
0.5839
8532
0.5688
80 mS
52.168
0.6521
48.384
0.6048