Hanna Instruments HI 83099 - Manual (Page 51)

101 100
Blank Sample
Blank
D.I. Water
Sample
Sample
Sample Blank
• 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.
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 2.0 mL of sample to one vial (sample vial), and 2.0 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 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, the samples may become turbid.
COD LR
OXYGEN DEMAND, CHEMICAL LOW RANGE
SPECIFICATIONS
Range 0 to 150 mg/L COD
Resolution 1 mg/L
Accuracy ±5 mg/L or ±5 % of reading @ 25 °C, whichever is greater
Typical EMC ±1 mg/L
Deviation
Light Source
Tungsten lamp with narrow band interference filter @ 420 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 remaining dichromate is
determined.
REQUIRED REAGENTS
Description Q.ty/test Q.ty/set
Reagent Vial 1 vial 25 vials
Deionized Wat+er 2.0 mL optional
Note: Store the unused vials in their container in a cool and dark place.
REAGENT SET
HI 93754A-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.
COD LR