Electro-Chemical Devices (ECD) CA6 Hardness Analyzer - Manual (Page 75)

11.0 REAGENT RECIPE and PROGRAM SEQUENCE
METHOD DESCRIPTION
The Hardness determination is a colorimetric analysis using a 572 nm LED and a heated colorimetric cell
of 16 mm diameter. After rinsing the hydraulic lines, the sample is pumped with the peristaltic pump
into the colorimetric cell. The reference measurement of the initial color is taken. Reagent 1, the
Cresolphthalein solution, is added using Micro Pump 1 and Reagent 2, the ethanolamine solution, is
added with Micro Pump 2. The solutions are mixed and a violet color develops proportionally to the
calcium and magnesium ions present. Absorbance is measured at the end of the reaction and the result
is displayed as Hardness as CaCO
3
ppb/ppm.
Wavelenght: 572 nm led
FIRST START-UP PROCEDURE
Open the liquids compartment (the bottom compartment)
Remove the protection paper that covers the glass colorimetric cell, unscrewing the black cell
Remove the plastic block in the pinch valve (see label)
Install the fast loop reservoir close to the right part of the analyzer and connect the cable of the level switch (fast
loop reservoir is an option for online applications)
Connect the drain of the fast loop reservoir with 12 mm tubing
Connect the sample feed to the fitting on the bottom part of the fast loop reservoir
Connect the Norprene tubing from the three way valve, sample port #1 to the fitting on top of the fast loop
reservoir.
Prepare reagents and fill the containers delivered with the analyzer
Put the reagent's containers in the dedicated bottle rack of the bench support (optional)
Switch on the analyzer and read the installation – start up procedure on the Help Menu pressing on “?” Button
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