Yellow Substances and automatic Turbidity Correction

The chlorophyll measuring instrument with algae class differentiation

The bbe FluoroProbe is a highly sensitive measuring instrument for the analysis of chlorophyll with algae class determination. Individual profiles during the measurements are taken for green algae, blue-green algae/cyanobacteria, diatoms/dinoflagellates and cryptophytes.

This enables the analysis of the occurrence and distribution of e.g. blue-green algae on site without the necessity of the laboratory. Possible interferences due to yellow substances are eliminated by an integrated CDOM correction factor.

Chlorophyll in vivo measurement can be affected by particulate matter in the water body.  Therefore a correction is essential when the turbidity is too high. The bbe FluoroProbe  with the optional transmission sensor provides automatic turbidity correction using the latest bbe++ software extension. Turbidity correction with the FluoroProbe makes chlorophyll determination even more reliable.

The bbe FluoroProbe can quickly and reliably determine the chlorophyll content of different algae classes down to a depth of 100m (optionally 1000 m). The measurement data can be displayed in real time on a PC or be stored in the probe for subsequent evaluation.

Measurement principle

The fluorescence of algae (emission at approx. 700nm wavelength) due to excitation by visible light mainly depends on the presence of chlorophyll-a, a common pigment in the plant world. The occurrence of other pigments is typical for the different algae classes. Interactions between these different pigment systems with chlorophyll-a result in a special excitation spectrum for the taxonomical algae classes.

The special patterns of this algae fluorescence - so-called fingerprints - are used in the bbe fluorometers for the quantification of different algae classes. The excitation light sources are LEDs with different wavelengths. The fingerprints of four algae classes and of yellow substances are already stored in the FluoroProbe. Special user-defined fingerprints can also be added.

NEW! Automatic turbity correction

Features & Informations

Advantages of the FluoroProbe

  • determination of green algae, blue-green algae (cyanobacteria), diatoms and cryptophytes
  • up to 4 other algae classes can be calibrated by the user
  • up to 4 measurements per second
  • yellow substances correction and compensation of interferences by UV-LED
  • turbidity correction
  • reduces the number of required microscopic laboratory examinations
  • internal rechargeable batteries
  • internal datalogger
  • PC software for data analysis
  • options: pressure sensor, transmission measurement


  • environmental monitoring
  • early warning system for algae blooms in limnological and marine waterways
  • bathing water monitoring of blue-green algae (cyanobacteria)
  • drinking water monitoring of (toxic) blue-green algae
  • pre-warning of the occurrence of poisonous algae (e.g. cyanobacteria toxins)
  • detection of chlorophyll and other pigments such as phycocyanine and phycoerythrine, fucoxanthine and peridinine
  • aquaculture monitoring
  • dam monitoring
  • algae distribution in the Arctic/Antarctic
  • oceanographic research
  • mooring, experiments, continuous analysis
  • limnological research
  • research and teaching
  • tracer measurements


The bbe FluoroProbe software supplied with the instrument facilitates detailed data analysis. All measurement data can be displayed numerically or graphically. Sections of data measurements can be recorded and printed using the zoom function. Data can also be exported to a spreadsheet program (e.g Excel). All settings and calibrations are performed by the software.

The screenshots below show examples of profiles of algae distribution in the Plussee (lake in Northern Germany) recorded in June 1999. The measurements were made at the same location at 10:00 a.m. and 12:00 noon respectively. The chlorophyll of the dinoflagellates was predominant in the group given in yellow. The change in the depth profile can be traced back to a vertical movement of the dinoflagellates, which actively moved to a deeper level due to adaptation to the current nutrient level.

The specific adaptation of the individual algae groups can be detected due to the cryptophytes, the maximum of which was found at about 5 m depth and did not change during the observation period. Blue-green algae and green algae also show a distribution in the depth profile, which is independent of time.

Hydro-Wiper unit to prevent biofouling

The FluoroProbe can now be operated on moored platforms, submersed from buoys or fixed measuring stations using the Hydro-Wiper (made by Zebra-Tech Ltd, NZ). The wiper brushes can be set to periodically clean the lenses of the measuring chamber to remove biofilms and dirt which builds up over long periods of operation.

2 operating modes

The Mobile Submersible Probe:
Fast and flexible chlorophyll concentration and algae class determination throughout a body of water

Laboratory Operation with a Workstation 25:
A workstation for 25ml glass cuvettes with a stirrer unit is available for laboratory operation. For more information, please see Ordering Info.

Technical specification of our FluoroProbe

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/brown algae [µg chl-a/l]
  • concentration of cryptophytes [µg chl-a/l]
  • fingerprints of classes/species, also user-defined [µg chl-a/l]
  • yellow substances
  • depth
  • temperature (optional)
  • transmission (optional)
Chlorophyll 0 - 200 µg chl-a/l
Resolution 0.01 µg chl-a/l
Transmission 0 - 100%
Temperature Sample: -2 - 40°C / Environment: -2 - 40°C
Housing material reinforced carbon fibre/V4A steel
Weight 6.4 kg (7.2 kg with lightshield)
Dimensions (H x D) 450 x 140 mm
Voltage 12 V
Battery capacity 3900 mA h
Operating time continuously up to 10 h; interval up to 30 days
Memory capacity 2 GB memory card, 10 million datasets
Interfaces RS485
Maximal diving depth
  • 0 - 100 m (standard)
  • 0 - 300 m (extended range1)
  • 0 - 1000 m (extended range2)
  • hard plastic case
  • power supply
  • protection cap
  • USB adapter
  • USB stick
  • manual
  • software
  • Temperature measurement
  • Transmission measurement (turbidity)
  • Cable lengths of 2, 5, 10, 20, 30, 50 and 100m
  • Workstation 25 (benchtop holder)
  • Wydro-Wiper Unit
  • Flow-Through Unit
  • Protective Cage
  • SDI-12 with bbe converter

Subject to alteration!

Available variants of the FluoroProbe

FluoroProbe - 1000m

Itemnumber: BG33000

Submersible spectrofluorometer for measurement of chlorophyll content in water (total content) and quantitative determination of different algae classes incl. pressure sensor, Gelbstoff sensor, internal datalogger, internal rechargeable batteries and external charger for batteries.

Principle of measurement:

  • determination of prompt fluorescence for the measurement of chlorophyll-a

Measurement range:

  • 0-200 µg chlorophyll-a/l
    high resolution 0.01 µg/l

bbe software:

  • chlorophyll determination & algae differentiation software


  • laptop,  PC or optional Bluetooth handheld


  • reinforced housing
  • resistant to water pressure at 1000 m depth
Request a quote

FluoroProbe - 100m

Itemnumber: BG35000

A submersible spectrofluorometer for measurement of chlorophyll content in water (total content) and quantitative determination of different algae classes incl. pressure sensor, Gelbstoff sensor, internal datalogger, internal rechargeable batteries and external charger for batteries.

  • for the measurement of marine microalgae, freshwater microalgae, nanoplankton, picoplankton, CDOM/yellow substances
  • with improved algae class differentiation and signal/noise ratio
  • for long-term measurement with energy-saving option
  • prepared for measurement of benthic microalgae with add-on kit

Principle of measurement:

  • determination of prompt fluorescence for the measurement of chlorophyll-a
  • determination of depth with pressure sensor

Measurement range:

  • 0-200 µg chlorophyll-a/l
  • high resolution 0.01 µg/l


  • internal microcontroller
  • battery-buffered memory

bbe software:

  • software chlorophyll determination & algae differentiation


  • laptop PC or optional BlueTooth handheld


  • carbon-fibre housing
  • resistant to water pressures at 100m depth (adjustment of depth of 300m possible)


  • 2 GB memory card for over 10 mio. datasets
  • USB connection
Request a quote

Available accessories for the FluoroProbe

Autostart Plug

Itemnumber: BG30113-V

The autostart plug enables interval measurements with the FP III submerged in the water without the use of a cable and PC.

Bluetooth handheld

Itemnumber: BG30221

This accessory kit for the FluoroProbe consists of bbe BlueTooth adapter for the FluoroProbe, currently a SAMSUNG Galaxy, and the bbe FluoroProbe app. The FluoroProbe app is already installed and enables quick and easy start-and-go. Data and parameters are transferred via BlueTooth between the FluoroProbe and the smartphone. All settings and data are displayed on the large, bright screen.
In addition the GPS-coordinates are stored together with each measurement. 

Underwater Cable for bbe FluoroProbe

Itemnumber: BG30196 - BG30201

The new lighter, thinner and stiffer cables for the FluoroProbe III are available in standard lengths from 10 to 100 metres.

Cable Reel with slip ring

Itemnumber: BG30192, BG30215

Up to 100m (40m) of cable can be transported more easily using the cable drum and reel. (The measureing cable is not included)

Calibration Cylinder FluoroProbe

Itemnumber: F30069

The calibration cylinder can be used with a small amount of algae solution (approx. 3l).

Flow-Through Unit

Itemnumber: BG30179

The Flow - Through unit is an add-on unit for the Fluoroprobe, which enables the instrument to use a defined flow of water for measurement underwater or in a measuring station. It is slid onto the outside of the FP and screwed into place.

Hard plastic carry case (for cables)

Itemnumber: E15614

This thin hard plastic case is for the transport of FluoroProbe cables, without foam cut-out. Dimensions: 60 x 50 x 15 cm. Weight approx. 4 Kg.

Hard plastic carry case

Itemnumber: E15615

This thick hard plastic case is for easy transport of the FluoroProbe instrument, with foam cut-out for cable adapter and charger, and lid compartment for smaller accessories and the manual. Dimensions: 60 x 50 x 21. Weight: 5 Kg. Supplied free-of-charge with any new FluoroProbe.

Hydro-Wiper for FluoroProbe

Itemnumber: BG30204 (30m) / BG30233 (100m)

The Hydro-Wiper has been developed for bbe by Zebra-Tech of New Zealand. It enables the instrument to remain submersed for longer periods of time without the need of being cleaned at regular intervals. The wiper brushes periodically clean the lenses of the measuring cell to remove and avoid the build-up of biofilms and dirt which can effect the accuracy of the measurements.

Protective Cage

Itemnumber: F30170

A steel cage to protect the FluoroProbe underwater from rocks, the quayside or the boat in rough seas or stormy weather. Weight approx. 5 Kg

RS 485/USB converter cable

Itemnumber: BG30103

The sensor works with a USB to RS 485 interface for the connection to the measuring PC.

Standard Utility Case (horizontal)

Itemnumber: BG30148

FluoroProbe Case (horizontal) for FlouroProbe and short cable.
The case protects the instrument during transport. The cases are equipped with stable hand grips to carry the weight comfortably and with stable fasteners to close the cases securely.

This case has room for the probe and accessories and up to 20m of cable.

Dimensions: 670 X 300 X 320 mm (LXWXH)

Standard Utility Case (vertical)

Itemnumber: BG30053

The standard utility case has a tube inside onto which the probe is placed to stop it moving during transport thus preventing damage, e.g. from the sides of the case. The cables and accessories are placed around the tube so that everything is to hand in one transport case.

Dimensions: 500 X 500 X 600 (LXWXH)

Temperature Sensor

Itemnumber: BG30056

This sensor measures the water temperature while the probe is in use.

Transmission sensor

Itemnumber: BG30055

Transmission measurement at 700nm (value 0-100%).

USB cable connector (supplied with FP III)

Itemnumber: BG30173

A short USB cable for connection to a USB stick/flashdrive and download all data automatically.


Itemnumber: BG30099/BG30229

Workstation25 benchtop unit:

  • workstation to hold the 25ml cuvette/sensor in position (horizontal operation)
  • optically sealed cover
  • cuvette for 25 ml capacity (outer dimensions 70x30x30 mm)
  • optional stirrer unit available

Downloads & Information about the BenthoTorch

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