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Brannstrom BilgMon 488 with cable

BilgMon 488 15 ppm Bilge Alarm 

The Brannstrom BilgMon 488 is a 15 ppm bilge alarm system for monitoring oil content in treated bilge water, type approved according to IMO MEPC.107(49). It combines a Sensor Unit (measuring cell) with a Master Unit for display, alarms and event logging, and is used with oily water separator (OWS) installations.

If you need a new version or have lost the BilgMon 488 software, please contact us for support.

Advantages for you:

  • Easy to operate
  • Compact system, ideal for retrofit
  • Stocked at Insatech warehouse
  • Sensor Unit calibration by replacement - easily done by the crew
  • Competitive price

We deliver directly and globally to end-users, agents, and resellers.
Contact us at quotes@insatech.com.

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BilgMon 488 Spare Parts

Looking for a replacement component rather than a complete system? 
Select the relevant part below or contact us with your installed system details.

Component Function
BilgMon 488 Master Unit Display, alarms and event log; IMO-required data retrieval via LCD or USB  
BilgMon 488 Black Sensor Unit Replacement measuring cell, delivered with a new calibration certificate (valid 5 years)  
BilgMon 488 Blue Sensor Unit Replacement measuring cell.  
BilgMon 488 Flow Switch Monitors sample flow; “No Flow” alarm is displayed and logged on Version 5 Master Units  
BilgMon 488 Calibration Check Kit Equipment for the 40 NTU calibration check, according to the manufacturer’s instructions  
Magnetic valve assembly Spare part for the BilgMon 488  

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How a 15 ppm bilge alarm works

A 15 ppm bilge alarm monitors the oil content of the separated/filtered water and stops the discharge into the sea if the oil content exceeds 15 ppm (parts per million). It is normally used together with the ship’s oil filtering equipment, also known as a bilge water separator or OWS system. The BilgMon 488 analyses the sample stream continuously and logs events in the Master Unit.

The BilgMon 488 is type approved according to IMO MEPC.107(49). In principle it can also be used as a simple oil content monitor in other applications, provided the water is free from solids or substances that may interfere with the measurement.

Replace instead of repair

When the 15 ppm bilge alarm on an existing ship is beyond repair, or repair would cost almost as much as a new unit, replacing it with a BilgMon 488 is usually the best solution. A new bilge water separator is normally delivered with a 15 ppm bilge alarm already installed.

Does your BilgMon 488 show an RTC failure alarm? The real time clock has stopped, which can often be solved by replacing the battery - see battery replacement below, or contact us for support.

Looking for a different model? See all our bilge monitors

Insatech Brannstrom Bilge Monitor 15Ppm 16 9

Simple Installation and Maintenance

The BilgMon 488 is designed for straightforward installation and replacement of existing 15 ppm bilge alarms. Its compact design makes it suitable for retrofitting a wide range of oily water separator (OWS) systems.

Maintenance is simplified through replaceable Sensor Units. When recalibration is required, the crew can replace the Sensor Unit onboard in approximately five minutes without replacing the Master Unit.

For technical instructions, refer to the BilgMon 488 owner's manual in the Downloads section.

Contact us now and let's talk price!

Retrofitting the BilgMon 488 to an Existing OWS

The BilgMon 488 can replace existing 15 ppm bilge alarms on many oily water separator (OWS) installations. Available in 24 V and 115/230 V configurations, it can typically be installed using new piping and electrical connections without hot work.

Before installation, verify the compatibility of the alarm relay output with the automatic stopping device (ASD). Relay ratings vary between product versions, and an external relay may be required depending on the ASD load.

Unsure whether the BilgMon 488 fits your existing OWS?

Contact our marine specialists with your current alarm model, OWS type and supply voltage.

Check Retrofit Compatibility

Brannstrom Bilge Monitor Tube Arrangement

BilgMon 488 calibration and calibration check

The maintenance schedule must cover two items:

  1. Sensor Unit calibration certificate - valid for 5 years. When it expires, the Sensor Unit is replaced, which the crew can do onboard in about 5 minutes without changes to the Master Unit. New Sensor Units come with a new calibration certificate: Black Sensor Unit / Blue Sensor Unit.

  2. Regular calibration check - can be done at shorter intervals than the certificate validity, using the Calibration Check Kit.

If the calibration check fails, clean the sensor thoroughly and check the installation for air bubbles or particles. If the fault remains, the measuring cell most likely needs to be replaced.

 

How to perform the calibration check

  1. Enter the “Check 40NTU cal” submenu of the cleaning & test menu.

  2. Press Enter to start the calibration test (the clean water valve will not open).
  3. Close the clean water supply.

  4. Drain the sensor and fill it with 40 NTU calibration fluid.

  5. The display must show a value between 80% and 100%. If it does, “OK” is shown above the RETURN button.

  6. Press RETURN to set the “Cal checked” date, shown in the “Sensor info” submenu.

The Calibration Check Kit contains: cleaning brush, syringe, 500 ml bottle with lid, 50 ml bottle of calibration check liquid, cleaning cap and instructions.

View the BilgMon 488 Calibration Check Kit

BilgMon 488 Version 5 - What’s new

BilgMon 488 Version 5 builds on Version 4 with enhancements designed for the evolving demands of marine operations, for both new installations and upgrades from Version 4.

Key improvements in Version 5:

  • Expanded signal capabilities: a new optional input for a flow sensing switch gives better operational oversight. A flow alarm is shown as “No Flow” on the display and recorded in the log.
  • Higher current handling: the upgraded ASD relay output accommodates higher current loads.
  • Smart maintenance: a sensor age reminder helps ensure timely Sensor Unit replacement and improves system reliability.
  • Customizable outputs: both analog (0–20 mA or 4–20 mA) and digital RS422 data outputs for flexible integration and reporting.

The Version 5 Master Unit and the Version 5 owner’s manual are available from Insatech.

BilgMon 488 Version 5 is engineered to provide superior functionality, ensuring compliance with stringent environmental regulations while delivering unmatched performance. Whether for new installations or seamless upgrades from Version 4, this new model is the ideal solution for maintaining safe and efficient marine operations.

 

Check Retrofit Compatibility

Brannstrom BilgMon 488 with calibration certificate

Upgrading from BilgMon 488 Version 4 to Version 5

Switching from Version 4 to Version 5 is straightforward with these considerations:

  • Terminal changes: most terminals keep their function, but the numbering has changed, so compare the wiring diagrams carefully before installation.

  • Compatibility: make sure the Sensor Unit (black, blue or silver) matches the specifications of the new Master Unit.

  • Optional flow switch: use the new flow switch input for added functionality, if applicable.

With careful planning, the upgrade gives you the full Version 5 feature set. For details, see How to change from Version 4 to Version 5, Replacing old Master Units with Series 5 units and the article on BilgMon 488 production versions.

Any Questions? Contact us now!

Flow Switch for BilgMon 488 Version 5

The optional flow sensing switch adds a critical layer of protection: it monitors the sample flow, helps prevent accidental pollution and supports compliance with MARPOL regulations. Only BilgMon 488 Version 5 is designed to fully integrate this feature.

Why choose Version 5 for flow switch integration?

  • Dedicated signal input: Version 5 has a specific input for the flow sensing switch. Flow alarms are treated as critical alerts, displaying “No Flow” on the screen and logging the issue for compliance and monitoring.
  • Accurate monitoring: Version 5 detects low-flow situations without compromising the logging of other system operations, such as separator activity.
  • Seamless integration: the flow switch integrates with Version 5 without the compromises older versions required, which simplifies installation.

The benefits of using a flow switch

Installed in the sample flow loop, ideally in the drain line, the flow switch detects blockages or tampering, helping to:

  • prevent accidental oil discharge
  • protect the environment
  • maintain operational safety

Models are available for specific flow rates, and the robust design is clog-resistant.

View the BilgMon 488 Flow Switch

Big containership sailing

Local alarm integration for oil content monitors

Industry standards require that oil content monitor (OCM) alarms are either displayed locally or integrated into the engine room alarm system. BilgMon 488 Version 5 has a built-in display and an integrated flow switch input, giving immediate alerts in case of system failure. On the latest Master Unit the flow alarm is treated like any other alarm (such as high oil content or malfunction): “No Flow” is displayed on the screen and recorded in the log.

Any Questions? Contact us now!

Rules and Regulations for 15 ppm bilge alarms

According to MARPOL Annex I, ships of 400 gross tonnage and above must be fitted with a bilge water separator. On ships of 10,000 gross tonnage and above, the separator must also be fitted with a 15 ppm bilge alarm.

Ships between 400 and 10,000 gross tonnage also need the 15 ppm alarm to operate the separator in these MARPOL Special Areas: the Mediterranean Sea; the Black Sea; the Baltic Sea and North West European waters; the Red Sea and the Gulf of Aden; the Arabian Gulf; the Oman area of the Arabian Sea. See Reg. 14 & 15 of MARPOL Annex I (Consolidated Edition 2006).

IMO MEPC.107(49): ships built before 2005 may operate with equipment meeting older IMO rules. Ships built in 2005 and later must have bilge separators and 15 ppm bilge alarms type approved according to MEPC.107(49) (see paragraph 1.3).

Port State Control: AMSA (Australian Maritime Safety Authority) officers inspect oily-water separators, filtering equipment and alarms per Resolution A.1185(33). They test that the sample flows to the 15 ppm bilge alarm and that the automatic stopping device activates above 15 ppm. Failure to meet MEPC.107(49) can result in non-compliance and vessel detention. Read more at AMSA.

Need more information? Contact us now!

Brannstrom Bilgmon 488 Unit 1X1

BilgMon 488 construction: Master Unit and Sensor Unit

The BilgMon 488 has two main components:

  • Master Unit - enclosure with LCD, buttons and LEDs. It houses the electronics for controlling the alarm and storing data; the event log memory is mounted in the lid.
  • Sensor Unit (Black / Blue) - enclosure with pipe fittings. It contains the electronics for measuring the sample stream and holds the calibration data. Communication with the Master Unit is wireless, so the Sensor Unit is hermetically sealed and must not be opened.

Any Questions? Contact us now!

How to maintain the BilgMon 488

Always check the expiry date of the Sensor Unit calibration certificate (5 years) as part of maintenance - see calibration.

Autoflush: the BilgMon 488 can be set to flush the sensor tube with clean water at intervals set in the settings menu. Autoflush only runs when the unit is in the main menu, not during monitoring or analysis.

Cleaning: use a soft bottle brush and mild detergent. Take care with the glass tube inside the Sensor Unit and avoid anything that can scratch it, such as metal objects. If the tube is coated with rust or similar deposits, a low-concentration acid such as hydrochloric acid can be used. Rinse thoroughly and protect your eyes, skin and airways. Always follow the manual.

If you have questions contact us now!

Mechanical Installation Bilgmon488 Brannstrom 1024 16X9

How to run a simulation

In the simulation menu you can simulate the ppm input from the Sensor Unit and the separator status, to check that the unit is installed correctly and responds to different oil content levels. Simulated events are logged, starting with SIM_ON and ending with SIM_OFF.

The BilgMon 488 must be in POWER mode (powered on, separator not running) to access the menu. See the simulation mode in the manual.

Get in Touch with Our Experts

Insatech Medarbejdere Website MSR
For technical questions

Martin Søvind Jensen

Tel: +45 2761 4502

Email: Marine@insatech.com

Write to Martin

Websitebillede Miho Hni Anan Frej (1)
For commercial inquiries

Our team of Sales Specialists

Tel.: +45 5537 2095

Email: quotes@insatech.com

 

Contact us now

We Deliver Directly to End Customers, Resellers, and Agents – Globally

At Insatech, we are proud to offer our high-quality products to all customers worldwide. Whether you’re an end customer, a reseller, or an agent, you can purchase directly from us.

By choosing us, you gain direct access to all our products, eliminating the need for intermediaries. Our global distribution possibilities ensure fast and reliable delivery to your doorstep, wherever you are.

We strive to make it easy for you as an end consumer to find the products you are looking for while supporting agents and resellers looking to grow their business. Whether you’re buying for your use or resale, we’re here to meet your needs.

Discover how simple it is to work directly with a trusted global distributor – shop with confidence at Insatech today!

Contact us here

Brannstrom Sweden

 

Why We Offer Brannstrom Products

Insatech offers Brannstrom solutions for their engineering precision, durability, and proven compliance with strict environmental standards. With full in-house design and manufacturing, Brannstrom delivers monitoring systems tailored to specific operational needs - for example the 15ppm bilge alarm type BILGMON 488

These solutions enable reliable performance and regulatory compliance across marine and industrial applications.

 

Bilge Alarm Tailored to Your Application

Brannstrom has a long tradition of developing application-specific systems, engineered in close collaboration with clients and tailored to their exact requirements - drawing on decades of design and development experience.

See all Brannstrom products here

Brannstrom Bm488 Cell
Specifications
Range

0...30 ppm
Resolution

0.1 ppm
Accuracy

According to IMO MEPC.107(49)
Response time

< 3 sec
Alarms
  • Alarm 1 (valve control) delay: 0-10 sec user adjustable
  • Alarm 2 (annunciation) delay: 0-600 sec user adjustable
  • Alarm points 1 and 2: 1-15 ppm user adjustable
  • Alarm hysteresis: 0.5 ppm (below alarm point)
Data storage and retrieval
  • Calibration storage: Stored in sensor housing
  • IMO required data: Stored in BilgMon488 main housing
    (sensor housing may be replaced with data remaining on board)
  • IMO required data retrieval: Via LCD display or USB
Output
  • 0...20 mA
  • 4...20 mA
Communications

USB serial communication (separate cable and software)

Product Specification and manuals

  • Data Sheet - BilgMon488 Bilge Monitor - Brannstrom
    English | pdf
  • Owners Manual - BilgMon488 Bilge Monitor - Version 4 - Brannstrom
    English | pdf
  • Article - BilgMon488 Bilge Monitor - Brannstrom
    English | pdf
  • Article - BilgMon488 Bilge Monitor- replacing old master units - Brannstrom
    English | pdf
  • Data Sheet- BilgMon488 flow switch - Brannstrom
    English | pdf
  • Brochure - BilgMon488 flow switch - Brannstrom
    English | pdf
  • Owners Manual - BilgMon488 Bilge Monitor - Version 5 - Brannstrom
    English | pdf
  • Appendix - BilgMon488 - how to change from version 4 to version 5 - Brannstrom
    English | pdf

Instruction manuals: Older versions

  • BilgMon488 Instruction Manual vT
    English | pdf

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