Conductivity Standards Table; Examples Of Temperature Coefficients (Alpha-Values); Practical Salinity Scale (Unesco 1978); Conductivity To Tds Conversion Factors - Mettler Toledo SevenGo Duo pro SG78 Instrucciones De Manejo

Appendix

11.3 Conductivity standards table

T (°C)
0
10
15
20
25
30
35

11.4 Examples of temperature coefficients (alpha-values)

Substance at 25°C
HCl
KCl
CH COOH
3
NaCl
H SO
2 4
HF
-coefficients of conductivity standards for a calculation to reference temperature 25 °C
Standard
84 µS/cm
1413 µS/cm
12.88 mS/cm

11.5 Practical salinity scale (UNESCO 1978)

In the SevenGo™ conductivity meters, 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
atmospher ic pressure is calculated as follows:
a = 0.0080
0
a = -0.1692
1
a = 25.3851
2
a = 14.0941
3
a = -7.0261
4
a = 2.7081
5
(32.4356 g KCl per 1000 g of solution)

11.6 Conductivity to TDS conversion factors

Conductivity
at 25 °C
42
10 µS/cm 84 µS/cm
6.13 53.02
7.10 60.34
7.95 67.61
8.97 75.80
10.00 84.00
11.03 92.19
12.14 100.92
Concentration
[%]
10
10
10
10
10
1.5
Measurement
temp.: 15 °C
1.95
1.94
1.90
b
0
b1 = -0.0056
b
2
b
3
b
4
b
5
TDS KCl
ppm value
500 µS/cm
315.3
359.6
402.9
451.5
500.0
548.5
602.5
Temperature coefficient alpha
[%/°C]
1.56
1.88
1.69
2.14
1.28
7.20
Measurement
temp.: 20 °C
1.95
1.94
1.89
= 0.0005
= -0.0066
= -0.0375
= 0.0636
= -0.0144
factor
1413 µS/cm 12.88 mS/cm
896 8.22
1020 9.33
1147 10.48
1278 11.67
1413 12.88
1552 14.12
1667 15.39
Measurement Measurement
temp.: 30 °C temp.: 35 °C
1.95 2.01
1.94 1.99
1.91 1.95
k = 0.00162
TDS NaCl
ppm value
pH/ORP/Ion/Conductivity meter SG78
factor