HydroSense 4420-OCM Continuous Closed-Loop for All Oil Types

HydroSense 4420-OCM Continuous Closed-Loop for All Oil Types


The HydroSense 4420-OCM PPM Oil Content Meter offers a low-cost approach to monitoring ppm concentrations of emulsified free oils in clean water. The 4420-OCM continuously monitors a clean water sample for oil leaks. The display, signal output, and alarm can be configured within the 0-250 ppm range. On-line alarm for oil presence in filtered effluent and cooling water.

The HydroSense 4420-OCM uses a light scatter technique to respond to oil contamination in the water. A slip stream approach directs a continuous sample flow through the HydroSense unit and back into the process stream. While it passes through the sample cell a controlled light source is directed into the water. The emulsified oils in the water will scatter the light toward the light sensors placed strategically around the cell. The intensity of light energy is measured to provide an indication of the ppm concentration.

Combining many unique design features into a compact package makes the 4420-OCM an ideal solution to monitoring for oil leaks in your water system.

Features & Benefits

  • Compensation for temperature and lamp deterioration minimizes re-calibration requirements
  • Long life LED
  • Compressed dry air inlet on sensor block keeps electronics dry in humid conditions
  • Continuous display updates every one second
  • No consumables or chemical used
  • Sample flow returns to the process
  • Sample cell can be exchanged with prepared samples for easy testing and calibration
  • Light scatter technology responds to petroleum, synthetic and vegetable oils
  • Continuous on-line monitoring without chemicals or lag time
  • A contamination sensor alert for cleaning
  • No tools necessary for routine maintenance

Technical Specifications

Control Unit

Operating Temp. 10˚C to 50˚C (optional to 90˚C)
Power Input 24 vdc or 110 vac or 220 vac
Alarm Relays 2 x 2 amp, SPDT, dry
Output 4-20 mA or RS-485
Standards UL, CSA, CE
Enclosure Type 4X polycarbonate, IP65
Range 0-250ppm, minimum alarm setpoint 3 ppm
Display Resolution 0.1 ppm
Instrument Accuracy +/- 0.1 ppm
Process Accuracy +/- 1.0 ppm under stable conditions
Oil Type All free and non-dissolved oils, > 2 micron


The performance is based on the site calibration to a known oil concentration in stable background water. Changes in oil make-up and background stability may affect the output. Through a simple calibration, this unit correlates well with laboratory ISO and EPA methods.