Electro-Chemical Devices (ECD) CA6 Hardness Analyzer - Manual (Page 81)

Fill a 1 liter volumetric flask to 2/3rds capacity with DI water. Add 200 ml of ethanolamine while stirring
the solution. Fill the volumetric flask to the gauge line (1 liter). Transfer to the reagent 2 container
provided with the analyzer.
11.4.3 Standard Solution
Standard Solution, 100 ppm as CACO
3
Part Number# 2010039-1
Calibration solutions can be made by diluting a 100 mg/l Hardness solution with an appropriate volume
of deionized water, 1.0ml of 100 mg/l (ppm) in 1 liter of water corresponds to a 100 ppb solution of
CACO
3
.
Preparation Standard solution 0.1 g/l = 100 mg/l
CACO
3
Dissolve 0.146 g CaCl
2
.2H
2
O in 1 liter of DI water
By diluting an appropriate volume of the standard solution with DI water, various calibration solutions
with a known hardness concentration may be prepared.
1.0 ml Stock into 1.0 liter DI water = 100 ppb Hardness standard solution
10.0 ml Stock into 1.0 liter DI water = 1000 ppb Hardness standard solution
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