Robotic BOD Analyzer

Biochemical Oxygen Demand (BOD) analysis is one of the most common applications for water laboratories. The test is used as an indication of the organic quality of water. With the SP2000seriesSkalar introduces the most flexible Robotic BOD platform available today. Besides the modern design and latest technology innovations, it has a flexible set up from 18 up to 198 BOD bottles. The analyzer is developed to fit your exact laboratory requirements with respect to sample throughput, level of automation, sample capacity etc. Analysis are carried out in accordance with all (inter) national regulations such as EPA 405.1/ISO 5815-1/ EN-1899-1/2, Standard Methods 5210 B, DIN 38409 etc. as well as customer specific methods.


The basic system:

The smallest and most basic Skalar Robotic BOD analyzer consists of a XYZ sample handling platform, a bottle tray with 18 BOD bottle positions, an oxygen probe and meter (accommodates optical or membrane style electrodes,) a manipulator, a stirrer, rinsing station and protective front and side covers.

In addition to this basic configuration the following automatic steps are available for complete BOD automation:

  1. Automatic addition of dilution water
  2. Automatic ATU dispensing
  3. Automatic Seed dispensing
  4. Automatic capping/ de-capping
  5. Automatic sample pipetting
  6. Automatic incubation

The systems can be extended to hold up to a maximum of 11 BOD racks and the use of multiple oxygen probes allow a higher sample throughput. A second arm can also be implemented to increase sample throughput or to perform additional tasks such as automatic sample pipetting into the BOD bottles or pH setting of the sample. The analyzer can be used with all available standard BOD bottles, and a wide range of sample trays can be provided for various incubators.  A completely closed cover is also possible for incubation purposes.


A typical BOD analysis sequence:  

Steps of Automation

  • Pipetting of the sample
  • pH setting of the sample
  • Addition of Nitrification inhibitor (ATU) and/or Seed
  • Addition of dilution water
  • Sample homogenization
  • Measurement of initial Dissolved Oxygen value (DO1)
  • Probe/stirrer rinsing between each measurement
  • Bottle capping/de-capping
  • Measurement of final DO2 value
  • Calculation of BOD according required regulations

Samples are pipetted, either manual or automatically, into the BOD bottles and the identity and the dilutions are entered or downloaded from LIMS into the sample table. Bottles are placed in the racks and placed on the Robotic Analyzer. Analyzer is started by operator. The bottle is decapped and filled with Nitrification inhibitor (ATU) and/or seed and dilution water. Sample is then stirred and the initial Oxygen value is measured. The bottle is capped and the Oxygen probe and stirrer are rinsed before going to the next sample. The same procedure is followed until a value is recorded for all samples. The sample racks are placed in a 20°C incubator for 5 days. After incubation the racks are placed on the Robotic analyzer. The operator starts the analyzer again. The bottle is de-capped. The sample is stirred and the final Oxygen value is measured. The BOD value is calculated. The bottle is capped. This procedure is repeated until all samples are measured. The data can be presented on screen, printed or converted to a file compatible with other software and LIMS’s.


If there is a requirement for other analyses such as pH, Conductivity, Alkalinity and Turbidity then these methods can be combined with BOD on the same robot.