Supervisor: Simona Ortelli

The instrument is used for water analysis, in particular for COD analysis (chemical oxygen demand). Its value, expressed in milligrams of oxygen per liter (mgO2/L), represents the quantity of oxygen necessary for the complete chemical oxidation of the organic and inorganic compounds present in a water sample. Together with BOD (biochemical oxygen demand) and TOC (total organic carbon), it represents one of the parameters commonly used for indirect measurement of the content of organic substances present in water.

Principle of operation

The tool offers a high-speed wavelength scan feature in the visible and UV spectrum and a solution that scans and tracks chemistry and samples with RFID tags. Then the instrument is able to perform classic spectrophotometric analyses but also analyses for the control of water quality, in particular COD, thanks to cuvette tests. They consist of pre-measured reagents for maximum safety for users thanks also to the closed system and the reduced quantity of reagents. They are easy to use and for a fast photometric evaluation they are equipped with a bar code label for automatic recognition in the spectrophotometer and calibration of Truecal. The cuvette test kit allows you to obtain precise and reliable results.

Main characteristics

This photometric system is designed to provide accurate results, supporting the operator in every step:

  • sample preparation: reduction of manual steps, precise dosage;
  • sample analysis: automatic recognition of the analyses, control of the expiry date, etc.;
  • results documentation: simple data management, control sheets.

In the daily water analysis routine, the DR3900 spectrophotometer optimizes processes and creates meaningful reports. Control parameters such as ammonium, COD, phosphate, nitrogen and many others are easy to determine.

DR3900 Hagh Lange spectrophotometer

  • Wavelength accuracy: ± 1.5 nm (wavelength range from 340 to 900 nm).
  • Photometric accuracy: 1 % from 0.50 to 2.0 Abs; 5 mAbs from 0.0 to 0.5 Abs.
  • Light beam height: 10 mm.
  • Wavelength calibration: automatic.
  • Cuvette compatibility: rectangular: 10, 20, 30, 50 mm, 1 poll.; round: 13 mm, 1 poll.
  • IBR+: automatic test recognition, batch and expiry date control.
  • Wavelength range: 320 – 1100 nm.
  • Photometric measurement range: ± 3.0 Abs (wavelength range from 340 to 900 nm).
  • Photometric linearity: < 0.5 % – 2 Abs; ≤ 1 % at >2 Abs with neutral glass at 546 nm.
  • Wavelength reproducibility: ± 0.1 nm.
  • Wavelength resolution: 1 nm.
  • Light source: gas-filled Tungsten (visible).
  • Specific technology: RFID for simple method update, sample ID and certificate of analysis.
Laboratory spectrophotomter with reference radius (RST) with new RFID technology.