Hanna Instruments HI 83208-2008 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

Nitrate

• Replace the cap and immediately shake vigorously up

and down for exactly 10 seconds. Continue to mix by
inverting the cuvette gently for 50 seconds, while taking

care not to induce air bubbles. Powder will not com-
pletely dissolve. Time and way of shaking could sensitively
affect the measurement.

• Reinsert the cuvette into the instrument, taking care

not to shake it.

• Press TIMER and the display will show the countdown prior

to the measurement or, alternatively, wait for 4 minutes
and 30 seconds and press READ. When the timer ends
the meter will perform the reading. The instrument
displays concentration in mg/L of nitrate-nitrogen.

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

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

INTERFERENCES

Interference may be caused by:
Ammonia and amines, as urea and primary aliphatic amines
Chloride above 100 ppm

Chlorine above 2 ppm
Copper

Iron(III)
Strong oxidizing and reducing substances
Sulfide must be absent