Hanna Instruments HI 83200C User Manual

Page 32

Hardness Mg

• Fill both cuvettes up to the 10 mL mark.

• Add 1 drop of HI 93719C-0 EDTA solution to one cuvette

(# 1), replace the cap and invert the cuvette several
times to mix. This is the blank.

• Add 1 drop of HI 93719D-0 EGTA solution to the second

cuvette (# 2), replace the cap and invert the cuvette
several times to mix. This is the sample.

• Place the blank (# 1) into the holder and close the lid.

• Press the

Zero key. The meter will show “-0.0-” when the meter is zeroed and ready for measurement.

• Remove the blank (# 1), insert the sample (# 2) into

the instrument, and close the lid.

• Press

Read to start the reading. The instrument displays concentration in mg/L of magnesium

hardness, as CaCO

Hardness Mg

MAGNESIUM HARDNESS

SPECIFICATIONS

Range

0.00 to 2.00 mg/L

Resolution

0.01 mg/L

Accuracy

±0.11 mg/L ±5% of reading at 25 °C

Typical EMC

±0.02 mg/L

Deviation
Light Source

Tungsten lamp with narrow band interference filter @ 525 nm

Method

Adaptation of the

Standard Methods for the Examination of Water and Wastewater,

edition, EDTA colorimetric method. The reaction between magnesium and reagents

causes a reddish-violet tint in the sample.

REQUIRED REAGENTS

Code

Description

Quantity

HI 93719

A-0

Mg indicator

0.5 mL

HI 93719

B-0

Alkali solution

0.5 mL

HI 93719

C-0

EDTA solution

1 drop

HI 93719

D-0

EGTA solution

1 drop

REAGENT SETS

HI 93719-01 Reagents for 100 tests
HI 93719-03 Reagents for 300 tests
For other accessories see page 128.

MEASUREMENT PROCEDURE

• Select the

Magnesium Hardness method using the procedure

described in the

Method Selection section (see page 12).

• Rinse a graduated beaker several times with unreacted sample,

before filling it to the 50 mL mark with the sample.

• Add 0.5 mL of HI 93719A-0 Magnesium indicator solution,

then swirl to mix.

• Add 0.5 mL of HI 93719B-0 Alkali solution and swirl to mix.

Use this solution to rinse 2 cuvettes.

10 mL

# 1

# 2