behr DT 20

Metering:

Time-optimized COD interval dosing: The metering of sulfuric acid is performed during several rounds, hereby, the samples are constantly cooled and stirred. This method facilitates the preparation of samples and, at the same time, prevents the non-standard overheating of the sample during addition

Titration:

Freely programmable "methods", e.g. end-point titrations, equivalence point titrations, linear, dynamic and quasi-dynamic titrations. Various password-protected user levels. Graphic printout with 1st and 2nd digestion. Freely selectable selection of printout of sample data. All national standards can be complied with for COD via "methods".

behr-specific dynamic titration instead of the generally common over-titration also guarantees exact end point recognition, even in the case of the COD-typical edge steepness and thus provides particularly exact measuring results.

Security for the user: Thanks to the automatic reagent addition, there never is a risk of coming into contact with the chemicals.

Practice-oriented and user-friendly software:

The entire programming process of the behrotest® DT20 is very easy and user friendly with the Windows user interface.

Automated COD determination with behr

Filling samples

When the samples are filled, the sample flasks are already in the sample rack, in the same order in which they are placed in the metering titrator and in the heating block. This makes sure that mix-ups do not happen.

Metering reagents

The samples are placed in the sample rack in the metering/titration unit DT20. There the reagents are prepared for COD determination, generally in potassium dichromate solution, containing silver-sulphate, in the exactly metered quantity and concentrated sulfuric acid, containing silver sulphate.

The sample arm contains the two metering lances for potassium dichromate and sulfuric acid. Their distance to one another corresponds to the distance between two rows of sample flasks in the sample tablet. If the metering lance for potassium dichromate is above the second row, the lance for sulfuric acid is therefore above the first.

To prevent the sample from overheating, the sulfuric acid can be metered in three portions ("interval metering"). The samples are in a water-traversed cooling trough to let off any heat resulting from the addition of sulfuric acid. To avoid overheating, it is also possible to meter the sulfuric acid in intervals.

Heating samples

Using the handling, the rack with the prepared samples is set in the heating block, the temperature program is started and the air condenser is set on the sample flasks. The samples are now heated for the designated time - generally 2 hours - to the boiling temperature of the water- sulfuric acid mixture.

Titrating and extracting samples

For titration, the racks with the samples is placed in the DT20 again. Instead of the measuring head, with which the reagents are metered during sample preparation, the titration head is set in the sample arm. It contains a titration lance and the Redox electrode for the recognition of the end point, as well as a suction lance for the titrated solution.

• Time-optimized interval dosing: The metering of sulfuric acid is performed during several rounds, hereby, the samples are constantly cooled and stirred. This method facilitates the preparation of samples and, at the same time, prevents the non-standard overheating of the sample during addition
• Security for the user: Thanks to the automatic reagent addition, there never is a risk of coming into contact with the chemicals.
• Practice-oriented and user-friendly software: The entire programming process is very easy and user friendly with the Windows user interface.
• For up to 12 samples simultaneously, incl. burette and cooling trough
• Reagent monitors ensure that there are enough chemicals in the bottle at the beginning of the action. Examinations that fail as a result of lacking reagents are ruled out.

• Environmental analysis - especially waste water & water