Hanna Instruments HI 83206-2008 User Manual

Page 27

Dissolved Oxygen

SPECIFICATIONS

Range

0.0 to 10.0 mg/L

Resolution

0.1 mg/L

Accuracy

±0.4 mg/L ±3% of reading

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 93732A-0

Reagent A

5 drops

HI 93732B-0

Reagent B

5 drops

HI 93732C-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 73.

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.

x 5

DISSOLVED OXYGEN

• Reinsert the cuvette into the instrument.

• Press TIMER and the display will show the countdown prior

to the measurement or, alternatively, wait for 6 minutes

and press READ. When the timer ends the meter will perform
the reading. The instrument displays concentration in mg/L

of nitrite.

• Press the or to access the second level of functions.
• Press the Chem Frm functional key to convert the result in mg/L of nitrogen-nitrite (NO

–

-N) and sodium

nitrite (NaNO

• Press the or to go back to the measurement screen.

INTERFERENCES

Interference may be caused by the following ions:
ferrous, ferric, cupric, mercurous, silver, antimonious, bismuth, auric, lead, metavanadate and chloroplatinate.
Strongly reducing and oxidizing reagents.
High levels of nitrate (above 100 mg/L) could yield falsely high readings due to a minute amount of

reduction to nitrite that could occur at these levels.

Nitrite LR