What is a water in fuel sensor?

A water in fuel sensor is a device that detects the presence of water in a fuel system. Often used for some control function when the moisture content reaches a determined set point.

What is the difference between moisture and free water measurements?

Moisture in a fuel is often detected at low levels and sensors have been designed to determine an increase in moisture levels over time.  Moisture meters normally respond very slowly and are limited in their range (only measuring moisture) but free water measurements enable operators to identify when other problems have occurred such as water break out.

The EASZ-2 can measure both gradual moisture increases over time as well as the presence of free water in real time.  Operators will have the added advantage of knowing when an event has occurred e.g. a sudden increase in water droplets in the fuel pipe during operation. Such measurements are taken once per second.

water in fuel sensor

The EASZ-2

The EASZ-2 moisture in fuel detector is a modern development  which performs highly repeatable and highly accurate online measurements of the water content in fuel with the option to transmit readings through traditional analog signals or Modbus.

In many instances, fuel is not normally supposed to contain any amount of moisture and quality checks/ manual sampling are not sufficient to determine contamination levels at all times.  The EASZ-2 was designed to continually provide the user with the actual state of the fuel in real time.  Armed with immediate real-time sensor data on the moisture contamination in a flow fuel stream, it is possible to correct process anomalies before they become too problematic.


The EASZ-2 is currently being manufactured and supplied to standard “off the shelf” applications but is not limited by its standard design. The product can be configured to meet additional requirements through the addition of add on boards and custom firmware. Consult EESIFLO to find out more on how we can be of assistance.


  • Zone 1 – Explosive Atmosphere Certification
  • Ability to measure low ranges of moisture in fuel
  • Measurement of total water in fuel or hydrocarbons in ppm or percent
  • Optional Loop powered outputs
  • Direct Temperature reading of Fuel with compensation
  • Immediate response to change in state of the fuel
  • Low, Medium and High Ranges


  • Diesel Contamination data collection
  • Any Fuel Type
  • Moisture in Hydrocarbons
  • Gas Condensate quality
  • Water in Fuel Emulsions
  • Fuel Separator Control
  • Thruster Sea Water Detection


  • Marine and Ship Building
  • Military Vessels
  • Power Plants
  • Engine Fuel
  • Fuel Quality Monitoring