Hanna Instruments HI 83200C User Manual

Page 30

Advertising

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,

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 128.

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.

• Press

Timer and the display will show the countdown prior to zeroing the blank or, alternatively, wait

for two minutes and press

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

measurement.

• Remove the cuvette.

• Insert the other cuvette (# 2) with the reacted sample into the

instrument.

• Press

Read to start reading. The instrument displays the results in mg/L of fluoride.

Note: For wastewater or seawater samples, before performing measurements, distillation is required.
For most accurate results, use two graduated pipettes to deliver exactly 8 mL of distilled water and
8 mL of sample.

Fluoride

# 2

INTERFERENCES

Interferences may be caused by:
Alkalinity (as CaCO

) above 5000 mg/L

Aluminum above 0.1 mg/L
Iron, ferric above 10 mg/L
Chloride above 700 mg/L
Phosphate, ortho above 16 mg/L
Sodium hexametaphosphate above 1.0 mg/L
Sulfate above 200 mg/L
Highly colored and turbid samples may require distillation
Highly alkaline samples can be neutralized with nitric acid.

# 1

# 2

Advertising