The cutting-edge Hydrosense 4410-OCM system from Arjay Engineering offers reliable, real-time flow-through parts-per-million (ppm) monitoring of both petroleum and non-petroleum oil in water.

The unique sensor design can optionally provide both fluorescence and light scatter simultaneously in one unit.

Fluorescence responds to dissolved and free (bouyant) hydrocarbons in water. This technology targets the aromatic hydrocarbons in the water and through a site calibration, correlates this to total oil.

Light Scatter can be used for turbidity indication or indication of free oils of any type, such as synthetic and vegetable.

The closed loop sample stream assembly communicates with the controller using a Modbus interface. This allows the sensor to be mounted remotely with two main benefits:

  • The sensor can be mounted close to the process to reduce lag time
  • The controller can be mounted in an area better suited to safe operator access and control wiring interface

The device is ideal for:

  • Oil / water separators, FWKO and treater effluents
  • Produced water
  • cooling water
  • De-salination and RO systems
  • Water treatment
  • Stormwater run-off

Features and benefits

  • LED light sources for stable long life
  • Multiple fluorescence excitation and emission wavelengths available to simultaneously define oil types
  • Light Scatter available with or without fluorescence for non-petroleum oils and turbidity
  • Cuvet available for manual sample insertion testing
  • Scale / algae Inhibitor module available for untreated waters
  • Easy calibration with menu-driven four-line display
  • Sensor block can be remote from controller to 1,200m
  • Compressed air inlet on sensor block for high-condensation applications


Range: 1ppm-200ppm or mg/l

Accuracy: +/- 1% of calibrated range

Resolution: 0.15ppm or mg/l

Sensitivity: 463ppb crude reference, 145ppb diesel reference

Process temperature: 0°C-55°C (32°F-130°F)

Pressure to Sensor: minimum 2psig (14kPa), maximum 150psig (690kPa)

Flow rate: auto-regulated to 1.0l/m

Power Input: 24vdc or 80vac-240vac

Enclosures: Type 4 / IP65 coated steel, 316SS or polycarbonate

Ambient temperature: 10°C-55°C (32°F-130°F)

Certified to: Electrical Safety Standards UL / ANSI, CSA and IEC Standard 61010-1


Also available with a purge / pressurisation system for Div 2 and Zone 2 installations.