Conductivity Standards; Practical Salinity Scale (Unesco 1978); Conductivity To Tds Conversion Factors - Mettler Toledo SevenEasy S30 Bedienungsanleitung

14.2

Conductivity standards

t(°C) 84 µS/cm
0 46 µS/cm
10 60 µS/cm
15 68 µS/cm
20 76 µS/cm
25 84 µS/cm
30 93 µS/cm
35 102 µS/cm
14.3

Practical salinity scale (UNESCO 1978)

In the conductivity meter the salinity is calculated according to the official definition of UNESCO 1978,
Therefore the salinity Spsu of a sample in psu (practical salinity unit) at standard atmospheric pressure
is calculated as follows:
a = 0.0080 b
0 0
a = -0.1692 b
1 1
a = 25.3851 b
2 2
a = 14.0941 b
3 3
a = -7.0261 b
4 4
a = 2.7081 b
5 5
(32.4356 g KCl per 1000 g of solution)
14.4

Conductivity to TDS conversion factors

Conductivity
at 25 °C ppm value
84 µS 40.38
447 µS 225.6
1413 µS 744.7
1500 µS 757.1
8974 µS 5101
12.880 µS 7447
15.000 µS 8759
80 mS 52.168
METTLER TOLEDO SevenEasy™ conductivity
1413 µS/cm 12.88 mS/cm
776 µS/cm 7.15 mS/cm
1020 µS/cm 9.33 mS/cm
1147 µS/cm 10.48 mS/cm
1278 µS/cm 11.67 mS/cm
1413 µS/cm 12.88 mS/cm
1552 µS/cm 14.12 mS/cm
1696 µS/cm 15.39 mS/cm
= 0.0005 k = 0.00162
= -0.0056
= -0.0066
= -0.0375
= 0.0636
= -0.0144
TDS KCl
Factor ppm value
0.5048 38.04
0.5047 215.5
0.527 702.1
0.5047 737.1
0.5685 4487
0.5782 7230
0.5839 8532
0.6521 48.384
TDS NaCl
Factor
0.4755
0.4822
0.4969
0.4914
0.5000
0.5613
0.5688
0.6048
Appendix
19