Myron L 9PTK with FCE Free Chlorine - Manual (Page 72)

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sanitizers than others.
The Myron L Company 9P avoids these pitfalls. The chemistry of the
test sample is left unchanged from the source water. It accounts for the
effect of pH on chlorine effectiveness by including pH in its calculation.
For these reasons, the Ultrameter III’s FC E feature provides the best
reading-to-reading picture of the rise and fall in sanitizing effectivity of
free available chlorine.
The 9P also avoids a common undesirable characteristic of other ORP-
based methods by including a unique Predictive ORP value in its FC E
calculation. This feature, based on a proprietary model for ORP sensor
behavior, calculates a final stabilized ORP value in 1 to 2 minutes rather
than the 10 to 15 minutes or more that is typically required for an ORP
measurement.
XXiv. alKalinity, harDness anD lsi FUnctiOns
A. Alkalinity and Hardness Titrations
The 9P uses a conductometric method of titration. This means that
instead of measuring a color or pH change, it measures the change in
conductivity when reagent is added. The way the sample solution behaves
is compared to the behavior of solutions of known alkalinity or hardness
under the same conditions. The equivalence point is determined from
the known data curve that best matches the experimental data.
B. Langelier Saturation Index
The LSI calculator and titration functions use a calcium carbonate
saturation index algorithm developed by Dr. Wilfred Langelier in 1936:
SI = PH + TF + CF + AF – 12.1
Where:
PH = pH value
TF = 0.0117 x Temperature value – 0.4116
CF = 0.4341 x ln(Hardness value) – 0.3926
AF = 0.4341 x ln(Alkalinity value) – 0.0074
The following is a general industry guideline for interpreting LSI values:
• An index between -0.5 and +0.5 indicates balanced water
• An index of more than +0.5 indicates scale-forming water
• An index below -0.5 indicates corrosive water
You can use the calculator to adjust any of the water balance
parameter variables used in the calculation to analyze the effect of the