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Hanna Instruments HI 83099 User Manual

Page 29

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57

56

Hardness Ca

• Add 1 drop of HI 93720C-0 EGTA solution to one cuvette (# 1), replace

the cap and invert the cuvette several times to mix. This is the blank.

• 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 and insert the second cuvette (# 2)

into the instrument.

• Press

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

hardness, as CaCO

3

.

• Press ▲ or ▼ to access the second level functions.
• Press the

Chem Frm key to convert the result in mg/L of Calcium (Ca

2+

).

# 1

# 2

# 1

Hardness Ca

CALCIUM HARDNESS

SPECIFICATIONS

Range

0.00 to 2.70 mg/L

Resolution

0.01 mg/L

Accuracy

±0.11 mg/L ±5% of reading at 25 °C

Typical EMC

±0.01 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,

18

th

edition, Calmagite method. The reaction between calcium and reagents causes a

reddish-violet tint in the sample.

REQUIRED REAGENTS

Code

Description

Quantity

HI 93720

A-0

Ca & Mg indicator

0.5 mL

HI 93720

B-0

Alkali solution

0.5 mL

HI 93720

C-0

EGTA solution

1 drop

REAGENT SETS

HI 93720-01 Reagents for 100 tests
HI 93720-03 Reagents for 300 tests
For other accessories see page 132.

MEASUREMENT PROCEDURE

• Select the

Calcium 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 93720A-0 Calcium indicator solution

and swirl to mix.

• Add 0.5 mL of HI 93720B-0 Alkali solution and swirl to

mix. Use this solution to rinse 2 cuvettes before filling
them up to the 10 mL mark.

# 1

# 2