• Portable BOD Detection

Portable BOD Detection

to Provide Real Time Monitoring of Organic Pollution

BODChek enables in-situ, real-time, monitoring of organic pollution within both natural water systems and water processing plants.

The monitor detects fluorescent proteins that are inherent within sewage and slurry and provides an output in BOD equivalent units.


The principle behind the measurement is the excitation and fluorescence of tryptophan-like compounds in the UV wavelength band. Tryptophan is an essential amino acid in human and animal diets. It is associated with microbial activity i.e. sewage and faecal contamination of wastewaters and has been shown to correlate with both BOD and bacterial contamination.

An internal calibration factor is used to convert the Tryptophan-like fluorescence to the reported BOD equivalent value in units of mg/L. The use of fluorescence provides signal detection sensitivity far superior to optical absorption methods currently in use, while the real-time reporting of BOD equivalence enables the measurement to be used for process control, which is not possible with conventional 5 day BOD laboratory techniques. BODChek provides a cost effective solution to organic pollution monitoring.

The system can combine a sensor with a depth rating of 600m with either a wireless roamer and Android enabled tablet or laptop connectivity. It provides a low cost, high performance sensor for marine, freshwater or process applications.

A Windows based interface is provided that allows the user to both plot and record time stamped data when operating the BODChek directly from a PC.


  • Small in-situ portable monitor providing real-time measurements with wireless connectivity ideal for field use
  • Fixed and flow-through configurations for on-line reporting
  • Real-time data displayed in BOD units
  • Combines high sensitivity with wide dynamic range
  • Robust stable performance
  • Digital and analogue output options including RS232, RS422, SDI-12, 0.5-5V DC and 4-20mA



  • Effluent contamination monitoring
  • Biological Oxygen Demand (BOD) Indicator
  • Combined Sewage Overflow (CSO)
  • Fish Kill investigations
  • Foul and surface sewer misconnection detection
  • Water catchment surveys
  • Coastal effluent monitoring



Size 70mm dia x 149mm
Weight in air 800g
Weight in water 150g
Pressure housing Acetal C
Depth rating 600 metres
Connector MCBH6M
Operating temperature -2°C to +40°C
Input volatage 9 to 36Vdc
Data output Digital RS232 and analogue 0.5 - 5V DC as standard
(Optional alternatives include digital SDI-12 and RS422, and analogue 4-20 mA)
Power requirements <1Watt @ 12 volt

Process explained

Fluorescence is the emission of light by a substance that has absorbed light. In most cases, the emitted light has a longer wavelength, and therefore lower energy, than the absorbed light. Fluorometry is the measurement of this fluorescence. Different molecules absorb and emit light at specific wavelengths. In order to effectively use Fluorometry as a tool for environmental analysis the specific wavelengths of the absorbed and emitted light for the target molecules/compounds needs to be known. Modern Water fluorometers use LED light source to excite the molecules and then measure the emittance at the desired wavelength. The intensity of the emitted light provides the concentration of the target compound.

What does the BODChek detect?

Parameter BOD
Excitation wavelength 280nm
Emission wavelength 360nm
Sensitivity 0.001 mg/L
Range (Factory set - can be extended) 0.001 to 35 mg/L