Myron L 9PTK with FCE Free Chlorine User Manual

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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

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

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