Hanna Instruments HI 83099 User Manual

Page 47

Dissolved Oxygen

• Let the sample stand and the flocculent agent will start to settle.

• After approximately 2 minutes, when the upper half of the bottle becomes limpid, add

10 drops of HI 93732C-0.

• Replace the cap and invert the bottle until the settled flocculent dissolves completely.

The sample is ready for measurement when it is yellow and completely limpid.

• Fill the cuvette up to the mark with 10 mL of the unreacted

(original) sample, and replace the cap. This is the blank.

• Place the cuvette into the holder and close the lid.

• Press the

Zero key. The display will show “-0.0-” when

the meter is zeroed and ready for measurement.

• Remove the cuvette.

• Fill another cuvette up to the mark with 10 mL of the reacted

sample and replace the cap.

• Reinsert the cuvette into the instrument.

• Press

Read to start the reading. The instrument will display the results in mg/L of dissolved oxygen.

10 mL

INTERFERENCES

Interferences may be caused by reducing and oxidizing materials.

Dissolved Oxygen

SPECIFICATIONS

Range

0.0 to 10.0 mg/L

Resolution

0.1 mg/L

Accuracy

±0.4 mg/L ±3% of reading at 25 °C

Typical EMC

± 0.1 mg/L

Deviation
Light Source

Tungsten lamp with narrow band interference filter @ 420 nm

Method

Adaptation of the

Standard Methods for the Examination of Water and Wastewater,

edition, Azide modified Winkler method. The reaction between dissolved oxygen

and the reagents causes a yellow tint in the sample.

REQUIRED REAGENTS

Code

Description

Quantity

HI 93732

A-0

Reagent A

5 drops

HI 93732

B-0

Reagent B

5 drops

HI 93732

C-0

Reagent C

10 drops

REAGENT SET

HI 93732-01 Reagents for 100 tests
HI 93732-03 Reagents for 300 tests
For other accessories see page 132.

MEASUREMENT PROCEDURE

• Select the

Dissolved Oxygen method using the procedure described in

the

Method Selection section (see page 12).

• Fill one 60 mL glass bottle completely with the unreacted sample.

• Replace the cap and ensure that a small part of the sample spills

over.

• Remove the cap and add 5 drops of HI 93732A-0 and 5 drops of

HI 93732B-0.

• Add more sample, to fill the bottle completely. Replace the cap

again and ensure that a part of the sample spills over. This is to
make sure that no air bubbles have been trapped inside, which
could alter the reading.

• Invert several times the bottle. The sample becomes orange-yellow

and a flocculent agent will appear.

DISSOLVED OXYGEN