Hanna Instruments HI 83099 User Manual

Page 48

Sample

Blank

D.I. Water

Sample

• Choose a homogeneous sample. Samples containing settleable solids need to be homogenized with a

blender.

• Preheat the Hanna Reactor HI 839800 to 150 °C (302°F). For correct use of the reactor follow Reactor

Instruction Manual.
Use of the optional HI 740217 safety shield is strongly recommended.
DO NOT USE AN OVEN OR MICROWAVE samples may leak and generate a corrosive and possibly explosive
atmosphere.

• Remove the cap from two Reagent Vials.

• Add exactly 0.2 mL of sample to one vial (sample vial), and 0.2 mL of deionized water to the other

vial (blank vial), while keeping the vials at a 45-degree angle. Replace the cap tightly and mix by
inverting each vial a couple of times.

Warning: the vials will become very hot during mixing, be careful when handling them.

• Insert the vials into the reactor and heat them for 2 hours at 150°C.

• At the end of the digestion period switch off the reactor. Wait for twenty

minutes to allow the vials to cool to about 120°C.

• Invert each vial several times while still warm, then place them in the

test tube rack.

Warning: the vials are still hot, be careful when handling them.

• Leave the vials in the tube rack to cool to room temperature. Do not shake

or invert them anymore otherwise the samples may become turbid.

OXYGEN DEMAND, CHEMICAL HIGH RANGE

SPECIFICATIONS

Range

0 to 15000 mg/L COD

Resolution

10 mg/L

Accuracy

±150 mg/L or ±3 % of reading @ 25 °C, whichever is greater

Typical EMC

±10 mg/L

Deviation
Light Source

Tungsten lamp with narrow band interference filter @ 610 nm

Method

Adaptation of the USEPA 410.4 approved method for the COD determination on
surface waters and wastewaters. Oxidizable organic compounds reduce the dichromate
ion (orange) to the chromic ion (green). The amount of chromic ion formed is
determined.

REQUIRED REAGENTS

Description

Q.ty/test

Q.ty/set

Reagent Vial

1 vial

25 vials

Deionized Water

0.2 mL

optional

Note: Store the unused vials in their container in a cool and dark place.

REAGENT SET

HI 93754C-25 Reagents for up to 25 tests

REQUIRED ACCESSORIES

HI 839800-01 Hanna reactor (115 VAC)
HI 839800-02 Hanna reactor (230 VAC)
HI 740216

Test tube cooling rack (25 holes)

HI 740217

Laboratory bench safety shield

For other accessories see page 132.

MEASUREMENT PROCEDURE

Before using the reagent kit carefully read all the instructions and the Material Safety Data
Sheet (MSDS). Pay particular attention to all warnings, cautions and notes. Failure to do so
may result in serious injury to the operator.

Reagent Blank Correction: This method requires a reagent blank correction. A single blank vial may be used
more than once. The blank vial is stable for several months (room temperature). For most accurate measurement,
run a blank for each set of measurements and always use the same lot of reagents for blank and samples.

Blank

Sample