COD Photometer HI 83214-02

photometer for measuring chemical oxygen demand (COD) and wastewater (chemical oxygen demand) / backlit display / intuitive handling / memory function and PC interface

This photometer HI 83214-02 is used to determine the chemical oxygen demand (COD), e.g., in industrial wastewater. Local health authorities are responsible for setting the initial values of the chemical oxygen demand. But how is this checked in the workplace? The photometer HI 83214-02 is ideal for daily measurement of the chemical oxygen demand (COD).

Definition of chemical oxygen demand (COD)

Chemical oxygen demand (COD) refers to the amount of oxygen (mass related to volume) required for the complete oxidation of organic substances (the greater percentage) and inorganic substances (of little significance). This chemical oxygen demand is measured in mg/l of O.₂.

The amount of oxygen needed for oxidation is obtained with a strong oxidizing agent (here with potassium dichromate). During the reaction, the chromium ion is reduced and changes from oxidation state (+VI) to oxidation state (+III). The determination of chemical oxygen demand serves to measure harmful substances and to interpret the degree of contamination of wastewater; moreover, its use is important as a control parameter in other fields such as power plants, the paper industry, or the environmental sector. It is also an important additional parameter for the control of wastewater conduits and treatment facilities.

The chemical oxygen demand (COD) can be determined using a colorimetric method. The test is performed in a medium with a strongly acidic pH with a certain amount of potassium dichromate (K₂Cr₂O₇). 

During the course of the chemical reaction, the dichromate ion transitions from oxidation state (+VI) to oxidation state (+III). Both types of chromium ions have a specific color that absorbs light of a special wavelength. The dichromate ion (CrO₇^2-) primarily absorbs light with a wavelength of 400 nm.

Chromate ion (Cr³⁺) absorbs light at 600 nm (standard method D520 D). The colorimetric determination of chemical oxygen demand allows for a measurement range greater than that of the titrimetric determination. The method covers a measurement range of 0 to 15000 mg/l O._2. The photometer HI 83214-02 can be used precisely up to this maximum value. 

- Gran pantalla LCD

- High precision

- With battery or with a 12 V adapter for 230 V current 

- Interfaz RS-232

- Consideration of reaction time

- Key for selecting measurement parameters

Technical specifications

Measurement ranges

See the table regarding this located further down

Light source

3 tungsten lamps with filters

For wavelengths of 420 / 525 / 610 nm.

Light detector

4 silicone photo cells

Power supply

2 x 9 V batteries or 12 V power adapter

Temperatura ambiental

Max. 50 °C, max. 95 % H.r.

Dimensions

230 x 170 x 70 mm

Peso

640 g

Other control parameters of the photometer HI-83214 

Contents of the shipment

1 x Monofunctional photometer HI 83214-02

3 x Cubetas

2 x Batteries

1 x 12V Adapter

1 x User manual

Don't forget to order the heating base along with the reagents if you want to determine the chemical oxygen demand., nitrogen and phosphorus!!!