Hanna Instruments HI 83266 User Manual

Page 13

Calcium Hardness

CALCIUM HARDNESS

SPECIFICATIONS

Range

0 to 500 mg/L (as CaCO

)

Resolution

5 mg/L

Accuracy

±10 mg/L ±5% of reading at 25 °C

Typical EMC

±5 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, 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 46.

MEASUREMENT PROCEDURE

• Select the

Calcium Hardness method using the procedure

described in the

Method Selection section (see page 15).

• Rinse a graduated beaker several times with deionized

water, fill a 1 mL syringe with the sample, and inject
0.5 mL into the beaker. Fill the beaker up to the 50 mL
mark with hardness-free water.

• 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.

Calcium Hardness

• 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

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

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

# 1

# 2

# 1

# 2