AlgaeOnlineAnalyser II

Algae Monitoring 24/7

Online detection of chlorophyll concentration, algae classes and photosynthetic activity.

The bbe AlgaeOnlineAnalyser II is deployed in measuring stations and laboratories in which online measurement of water quality is required for rivers, reservoirs, dams and lakes as well as in drinking water production. The instrument impresses due to its rapid analysis of chlorophyll concentrations. The chlorophyll concentration, the transmission and optionally the photosynthetic activity are determined simultaneously.

The detection of different algal classes by excitation with coloured LEDs distinguishes this measuring instrument from its competitors. Part of the analysis is a yellow substances (CDOM) measurement to adjust the calculation of the total chlorophyll content. The integrated cleaning unit protects against growth problems during long-term measurement.

Measurement principle

The fluorescence of algae via excitation by visible light mainly depends on the chlorophyll-a, a common pigment in the plant world. The presence of other pigments indicates different algae classes. The interaction of these different pigments with chlorophyll-a results in a special excitation spectrum for taxonomic algae classes.

The special patterns of this algal fluorescence - so-called fingerprints - are used in bbe fluorometers for the qualification of different algae classes. The light sources for the excitation are LEDs with selected wavelengths. The fingerprints of four algae classes and for yellow substances are pre-defined in the instrument. However, user-specific fingerprints can also be defined.

The physiological performance of the algae (algae activity) on photosynthesis is determined by exitation using additional background light. The resulting variable fluorescence allows the calculation of algae activity given as the Genty parameter. This Genty parameter represents the quantum yield and is also an expression of the vitality of the algae.

Features & Informations


  • quick, simple chlorophyll determination using algal class analysis
  • determination of the photosynthetic activity of algae
  • maintenance-free
  • simple operation
  • different communication possibilities also for industrial applications:
    • up to 8 alarm outputs (potential-free contacts)
    • up to 16 analog outputs (4-20mA)
    • serial interface for data transfer
    • Ethernet - access to data from an external PC
    • USB connector for data transfer
    • optional ModBus connector
  • direct measurement without sample preparation via filtration, dilution
  • integrated cleaning unit reduces maintenance to a minimum
  • touch screen display
  • PC operation using bbe AOA software
  • water temperature measurement
  • Extension for the AlgaeOnlineAnalyser
  • A regulated inflow of sample water enhances the versatility of the AlgaeOnlineAnalyser: a valve switches alternatively between two tubes of the AlgaeOnlineAnalyser. The cycle time is controlled by the AOA software. This new feature enables the user to take water samples from different depths or locations, and measures algae chlorophyll online at high frequency. The records allow the user to draw conclusions about the success of the measurements in order to reduce or enhance microalgae in process water, cooling water or a culture.


  • waterway analysis and assessment
  • environmental assessment
  • intake monitoring
  • chemical assessment
  • desalination plants
  • dam monitoring
  • cooling water and production water monitoring
  • limnological work
  • research and education


The database software is used to record and analyse the data. The most important features are...

  • saving of data and parameters at any time
  • graphic display of all measurement values
  • online display in LAN
  • calibration of the instrument
  • parameterisation of the measurement
  • data export to EXCEL and to text files
  • print function
  • subsequent recalibration of algae classes

Technical specification of our AlgaeOnlineAnalyser II

Description Value
  • total chlorophyll [µg chl-a/l]
  • concentration of green algae [µg chl-a/l]
  • concentration of cyanobacteria [µg chl-a/l]
  • concentration of diatoms [µg chl-a/l]
  • concentration of cryptophytes [µg chl-a/l]
  • fingerprints of classes/species, also user-defined (e.g. Planktothrix rubescens) [µg chl-a/l]
  • yellow substances
  • transmission (at 5 wavelengths)
  • water temperature
  • photosynthetic activity (Genty) (optional)
Chlorophyll 0 - 500 µg chl-a/l
Measurement procedure spectral fluorometry
Resolution 0.01 µg chl-a/l
Transmission 0 - 100%
Measuring chamber cleaning automatic cleaning piston
Housing material V4A steel/aluminium/coated steel plate
Weight 19 kg
Dimensions (H x W x D) 438 x 551 x 250 mm
Protection class IP54
Mains voltage 110/240V 50/60Hz
Power consumption 100 W
Temperature Sample: 0 - 35 °C / Environment: 0 - 40° C
Sample volume 30 ml
Maintenance interval > 7 days
Sample inflow free pressureless inlet /peristaltic pump
PC internal PC with touchscreen and bbe++ software
OS Windows
Outputs (options)
  • modem
  • analogue output 4-20 mA (up to 16)
  • relay output (up to 8)
  • Modbus TCP/IP
  • SDI-12 with bbe converter

Subject to alterations!

Available variants of the AlgaeOnlineAnalyser II

AlgaeOnlineAnalyser II

Item number: BG0089.0000

A spectrofluorometer for the measurement of chlorophyll-a in water (total content) in a flow-through cell with tubing.


  • algae differentiation
  • yellow substance measurement
  • extended sensitivity
  • transmission measurement
  • automatic cleaning device
  • peristaltic pump
  • bbe software for Windows

Principle of measurement:

  • determination of prompt fluorescence and calculation of chlorophyll-a

Measuring range:

  • 0-200µg chlorophyll-a/l
  • resolution 0.1 µg/l

Operation and data exchange:

  • RS232/USB
Request a quote

AlgaeOnlineAnalyser II - with Genty-parameter detection

Item number: BG0088.0000

A spectrofluorometer for the measurement of chlorophyll-a in water (total content) in a flow-through cell with tubing.


  • activity measurement (Genty parameter)
  • algae differentiation
  • Gelbstoff measurement - Yellow Substances
  • extended sensitivity
  • transmission measurement
  • automatic cleaning device
  • peristaltic pump
  • bbe software for Windows XP Professional

Principle of measurement:

  • determination of prompt fluorescence and calculation of chlorophyll-a
  • determination of the variable fluorescence according to photosynthetic activity as described by Genty

Measuring range:

  • 0-200µg chlorophyll-a/l
  • resolution 0.1 µg/l
  • resolution for Genty parameter 3 µg/l

Operation and data exchange:

  • bbe software
  • serial communications RS232/USB
Request a quote

Available accessories for the AlgaeOnlineAnalyser

Wallmounting bracket (AOA/AG)

Itemnumber: BG0080.0091

Wallmounting bracket made of aluminium to attach the instrument to any vertical, flat surface at a distance of approx 500 - 1000mm. Can also be used to swivel the unit for better viewing perspective.

Protocoll Coverter SDI12 and serial

Itemnumber: BG0036.0900

Translates the measurement results from the bbe protocol to SDI12 etc.

position of switch: bbe device: protocol of data logger:
0 FluoroProbe SDI-12
1 AlgaeGuard EMC-1
2 AlgaeTorch AOA-Protocol
3 AOA SDI-12
4 AlgaeTorch SDI-12
5 PhycoProbe SDI-12
6 AlgaeTorch EMC-1
7 AlgaeGuard SDI-12

Dimensions: 16 x 9.5 x 5.5 cm, ~440g

Voltage: 100 – 240 V / 50 – 60 Hz (power supply unit)


Control Unit with Switching Valve (AOA)

Item number: BG0080.0150

This control unit enables the AOA to get samples from different sources. The valve switches between those sources so that the AOA can analyse different sample waters consecutively.
(for 2 sample inlets - up to 8 possible in total)

Downloads & Information about the AlgaeOnlineAnalyser

Manuals, software and further informations for this product may be available in the internal area for registered users.