Water-in-Oil Sensor

PAJ has from specifications from MAN Diesel & Turbo Copenhagen developed and manufactured a sensor for marine user, that measures water content in lubrication oil. The water-in-oil sensor can be used to measure the water activity in the lubrication oil of a marine engine and other applications, where it is crucial to measure the water content in oil.

It is important to keep the quality of lubricating oil, on large 2-stroke engines at a constant high level. An essential part of this monitoring is to ensure that the water activity does not exceed specified limits.

Water in lubricating oil can come from various sources, such as leaking coolers, or leaking parts within the coolant system.

Problems arising in connection with water in lubricating oil are corrosion of engine parts, reducing the oil's ability to withstand pressure, water emulsification, leaching of oil additives, etc,.

The traditional standard procedure for monitoring is carried out by taking an oil sample and analyzing it, either aboard ship or by sending it to laboratories ashore.

This approach has some drawbacks:
  • The small oil sample volume constitutes a problem. It may not represent the many tons of oil.
  • Some time will elapse before the result returns from the lab.
  • The analysis is typically only conducted one per week or twice a month.
  • If the test is conducted aboard its highly dependent on the crew personnel.
  • When the result return, the damage might actually have taken place already, due to high level of water in the oil.


  • These drawbacks can be eliminated by installing PAJ WIO200 Water-In-Oil sensor in the lubricant oil system.

    WIO200-sensor:
  • Performs measuring on the entire oil volume
  • Online measuring 24-7
  • The measurements are independent of the crew on board
  • Early alarm at unacceptable amount of water
  • Can be connected directly to the ships existing monitoring system


  • When water in the lubricating oil is detected early, the crew may intervene before damage occurs to the machinery and expensive accidents can be prevented.
  • Robust industrial design
  • High accuracy
  • Water in oil
  • Moisture in oil
  • Relative humidity
  • Water activity
  • Easy to install
  • Easy to connect
  • Equipped with two alarms (High and HighHigh)
  • Calibrated in lubricant oil
  • Germanisher Lloyd Type Approved
  • MAN Diesel & Turbo Approved
  • Oil monitoring
  • Continuous in-situ on-line measuring
  • Early warning for corrective actions
  • Checking all oil volume not only a sample
  • Calibrated for actual oil
  • Oil analysis
  • Protects oil and equipment
  • Avoid oil problems and oil degradation
  • Separators, filters and driers only running when actually needed
  • Protects the environment
  • Relay contact potential free for each H- and HH-alarm set according to requirement
  • No human error possible
  • CE marked
  • Produced according to ISO9001 and ISO14001
  • No work for engine room crew
  • No waiting for lab results
  • Direct connection to Engine Room Control System potential free (4-20mA)
  • Robust IP65 design
  • Sensor, Water sensor, Oil sensor
  • Lubricant, Hydralic oil, Diesel


  • Monitoring Water in Lub Oil
    PAJ WIO200_DIMAR-TEC presentation
    Water-in-Oil sensor Data Sheet
    Water-in-Oil sensor Integrated Data Sheet