Be confident in
your ballast water
- and prove it

Ballast Water Monitoring A/S manufactures the World’s only real-time performance monitor for Ballast Water Treatment Systems

Ballast Water Treatment Systems (BWTS) are costly, and their treatment performance is difficult to measure. Nevertheless, the shipping industry must adhere to the IMO Ballast water Convention and the USCG regulations, and consequently all discharged ballast water must fulfill the IMO D-2 criteria by September 2024 – and a large part of the world’s fleet must fulfill these already today.

It is our mission to encourage shipping industry’s confidence in their BWT systems by using first rate analytical instruments.


bw-monitor™ provides automated
in-line and on-time data on the performance of your ballast water treatment system.

bw-monitor™ is the ONLY in-line system for monitoring the biological efficacy of BWTS.

bw-monitor™ is the ONLY continuous and automated system requiring no crew interaction during cargo operations.

bw-monitor™ is the ONLY system testing all the ballast water – not just small samples.

bw-monitor™ is the ONLY system providing real time BWTS performance information based on biological water conditions.

Our sensor units monitor your ballast water treatment during cargo operations in due time for adjustments to be made or corrective actions to be carried out while the BWTS is still running.


“The bw-monitor™ is just about the only indicative compliance device around for in-line monitoring of ballast water treatment. We get high resolution data and it is our first choice for automated onboard monitoring.

The bw-monitor™ works with all BWT systems in all water conditions.

bw-monitor™ automatically and continuously surveys the functionality and efficacy of your BWTS directly in the ballast line.

bw-monitor™ automatically adjusts to the characteristics of the incoming water and gives the operator an instant status indication of the BWTS.

bw-monitor™ measures and reports on the performance of filters and the biological efficacy of the disinfection unit based on biological conditions before and after the BWTS.

Our monitoring technology works with all BWTS and can be set up for your specifications and included in your predictive maintenance system.

bw-monitor™ does not require any chemicals or consumables.

bw-monitor™ is permanently installed onboard.





Laser scattering:

  • Measuring frequency: 37 kHz
  • Light source wavelength: 650 nm

Fluorescence measurement:

  • Excitation wavelengths: 430 and 460 nm
  • Emission wavelength: 680 nm
  • Measuring frequency: 8 kHz


  • Sensor unit
    Dimensions: Please see drawing
    Weight: 13 kg
    IECEx/ATEX protection: Ex mc
  • Electronics cabinet
    Dimensions: 400 mm × 400 mm × 210 mm
    Weight:13 kg
    IP Code.44
  • Power: 230 VAC


The bw monitor logs real time data for maintenance or compliance purposes

Predictive maintenance

Our technology provides a wealth of data on the performance of filter and treatment equipment from every ballasting operation covering all ballast tanks from start to end. Minor and major malfunctions are recorded and shared with us or the predictive maintance capacity of your choice for diagnostic and prognostic use. Already after a few months of operation you will better prepared to modify and improve operation of the BWTS.

Indicative D-2 compliance

The laser and fluorescence methodology provides you with performance data on filter efficacy and immediate kill rate according to criteria for your BWTS.  Although, the bw-monitor is not a port state control system for D-2 compliance it can be modified to provide indicative compliance data according to IMO standards. The data is available already on uptake when it is not too late for any corrective use. The bw monitor can also be used to assess treated water on discharge, or installed in a sideline used for monitoring equipment – whatever is most compatible with your BWTS’ design.

Logging and transmitting data

The bw monitor logs real time data and provides a tamper-proof report of indicative compliance data for you – and for port state control. The bw monitor can also provide data via the internet on the functionality of a BWTS directly to the shipowner. The data can also be shared with the BWTS manufacturer for improvement or guarantee purposes with no hazzle to the crew. The bw monitor can be accessed remotely for software modification and algorithm updates. All data traffic is protected by end-to-end encryption. Data is transmitted in small compressed packages and will select the cheapest connection available.

Color codes

  • Waiting for input from sensors
  • Water has very low phytoplankton content
  • Treatment status is OK
  • Alarm mode – treatment does not meet requirements
  • Cannot connect with sensors / service mode


bw monitor can be installed when the ship is in port

Installation is simple and operation is cheap

The bw monitor has passed all environmental tests: it has been tested in IMO G8 and USCG land-based full-scale facilities, and it has been operated in combination with UV and electrolysis based BWTS onboard several vessels. The monitoring system comprises two stainless steel sensor units, a control unit in IP44 cabinet, and a display unit with a simple user interface. Installation is straight-forward.

The sensors are fitted with DN150 flanges and easily mounted on prepared studs in the ballast line: they can be operative in just a few hours.  The bw monitor is completely automatic: it uses no consumables and only minimal energy, and its operation does not require any interaction by the crew.


The full documentation with just one click

We have uploaded all documents regarding the ballast water monitoring system. You can download everything needed for your documentation with just one click. If you do not find the information needed please call us or email



QMS, ATEX and IECEx Certificates

  • ISO 9001:205
  • ATEX CAT 3G Conformity Certificate
  • Quality Assurance Notification Annex IV
  • IECEx Cetificate og Conformity


Ballast Water Monitoring A/S
Nymøllevej 50
2800 Lyngby


Telephone: +45 27 82 54 48

Insatech Marine A/S
Næstvedvej 73C
DK-4720  Præstø


Telephone: +45 82 82 93 55



Elcome International LLC
Dubai Investments Park 598-1121
DIP Phase 1, PO Box 1788 Dubai,
United Arab Emirates


Telephone: +971 4 812 1333