ECscan20/30/40
Appendix
Preparation of Conductivity Standard Solutions
1.
Place the analytical grade potassium chloride (KCl) reagent in a beaker and dry in an oven for about 3 hours at 105° C/221° F, then cool to
room temperature.
2. Add the reagent to a 1 litre volumetric flask according to the instructions in table below.
3.
Fill the deionized water to the mark, mix the solution until the reagent is completely dissolved.
Conductivity Standard
Reagent
Weight
84
µ S/cm
KCl
42.35
mg
1413
µ S/cm
KCl
745.9
mg
12.88
mS/cm
KCl
7.45
mg
Calculating the TDS Conversion Factor
The following formula describes the calculation method of TDS conversion factor.
Factor =
Where:
Actual TDS = Value from the high purity water and precisely weighed NaCl or KCL reagent.
Actual Conductivity = The meter measured conductivity value.
For example, dissolve 64 grams of KCl reagent in 1 litre deionized water. If measured conductivity value is 100
mS/cm, then TDS factor is 0.64.
Conductivity to TDS Conversion Factors
Conductivity at 25° C
TDS (KCl)
TDS (NaCl)
ppm
Factor
ppm
Factor
84
µ S/cm
40.38
0.5048
38.04
0.4755
1413
µ S/cm
744.7
0.527
702.1
0.4969
12.88
mS/cm
7447
0.5782
7230
0.5613
Optional Accessories
Order Code
Description
E-ECscan-C1-10K
Platinum conductivity electrode, cell constant 1, measurement range: 10
μ
S/cm to 20
mS/cm
E-ECscan-C10-10K
Platinum conductivity electrode, cell constant 10, measurement range: 100
μ
S/cm to 200
mS/cm
ECCS-84
Conductivity standard solution 146.5
μ
S/cm, 480
ml
ECCS-1413
Conductivity standard solution 1413
μ
S/cm, 480
ml
ECCS-1288
Conductivity standard solution 12.88
mS/cm, 480
ml
Actual TDS
Actual Conductivity @25° C