LaMotte CORROSION CONTROL Test Kit - Manual (Page 6)

INDEX CALCULATION CHART
Total Dissolved Solids
Calcium Hardness &
Total Alkalinity Temperature
ppm = CF ppm = AF °C = TF
0 9.70 10 1.00 0.0 2.60
100 9.77 25 1.39 4.0 2.50
200 9.83 50 1.70 8.0 2.40
300 9.85 75 1.87 12.0 2.30
400 9.86 100 2.00 16.0 2.20
600 9.87 150 2.15 20.0 2.10
800 9.89 200 2.30 25.0 2.00
1000 9.90 300 2.48 30.0 1.90
400 2.60 40.0 1.70
800 2.90 50.0 1.55
1000 3.00 ¾ ¾
EXAMPLE: A water sample was tested and found to have the following
characteristics:
Test
Measured
Value
Factor
Factor Value
from Chart
Temperature 10.0°C TF (Temperature Factor) 2.35
Total Dissolved
Solids 300 ppm TDSF (Total Dissolved
Solids Factor) 9.85
Calcium Hardness 75 ppm CF (Calcium Hardness
Factor) 1.87
Total Alkalinity 100 ppm AF (Alkalinity Factor) 2.00
pH 8.5 pH 8.5
CALCULATIONS:
Soluability pH (pHS) = TF + TDSF - CF - AF
pHS = 2.35 + 9.85 - 1.87 - 2.00
pHS = 8.33
Langelier Saturation Index (LSI) = Measured pH - pHS
LSI = 8.5 - 8.33
LSI = 0.17
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