Home > Probes > PAH probes microFlu and enviroFlu, oil sensors in water

PAH probes microFlu and enviroFlu, oil sensors in water

Hydrocarbons monitoring in water

The PAH probes, microFlu and enviroFu, are robust sensors for online monitoring of hydrocarbon in water.

Directly immersed, even highly loaded waters, PAH probes make it possible to detect and measure the oil content in all types of water. These hydrocarbon detectors can be suspended in a collection manhole, mounted on a by-pass system thanks to a flow cell or fixed on a float to follow the surface where the oils decant quickly.

Our UV fluorimeters are calibrated in the factory and delivered ready to use. Their operation is autonomous and cleaning can be automated. PAH probes connect to TriBox controllers for data display and recording, or could be directly connected to a PLC using several available output signals (analog and digital).

For the most demanding applications such as drinking water production, the enviroFlu PAH probe allows very low detection levels and very high measurement accuracy. At the end of 2021, a new version of the UV fluorimeter was developed, the microFlu V2 HC probe. It uses the frame of its big sister (enviroFlu), which has proven itself throughout the world. Smaller, more manageable and cheaper, the microFlu V2 HC is particularly suitable for monitoring hydrocarbons entering wastewater treatment plant or for detecting oil concentrations in discharge and rain water.

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Whether it is a question of controlling discharges or detecting pollution in the natural environment, the monitoring of hydrocarbons in water has become a priority for public authorities. Our energy consumption as well as the increase in industrial production intensify hydrocarbon pollution in water. Faced with the health and environmental problems encountered, it is essential to strengthen detection in the natural environment. Compliance with the standards of the Water Framework Directive 2000/60 / EC aims to obtain a good chemical status of surface water.

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Measurement principle

The PAH probe is a fluorimeter that precisely measures the concentration of Polycyclic Aromatic Hydrocarbons (PAH) in water. These PAH result from the incomplete combustion of petroleum and are present in most mineral oils or fuels. The sensor measures the sum of the PAH passing in front of the lens.
Wi, the proportion of PAH in oils is set at 3.33% for conversions into total hydrocarbons. This ratio can be modified depending on the type of hydrocarbon present. (diesel, kerosene, heavy fuel ...)


  • Monitoring drinking water resources
  • Biological wastewater treatment plants protection
  • Control of industrial discharges
  • PAH measurement in process water
  • Protection of membranes in desalination plants
  • Control of washing water from purifiers on ships
  • Pipeline monitoring
  • Bilge water monitoring


  • In situ measurement, no sampling no reagents
  • Optical window with coating to minimize clogging
  • Automatic cleaning by compressed air injection
  • Operation even in wasted water
  • Float mounting for monitoring variations in water levels
Principles of measurementenviroFlu HC : xenon flash lamp + filter 254 nm
microFlu HC : LED + filter 255 nm
Detectorphotodiode + 360 nm filter
ParametersPAH polycyclic Aromatic Hydrocarbons, oils
Measurement ranges - enviroFlu HC 500PAH : 0...50 ppb, 0...500 ppb (phenanthrene) (THC : 0...1,5 ppm, 0...15 ppm equivalent)
Measurement ranges - enviroFlu HC 5000PAH : 0...500 ppb, 0...5000 ppb (phenanthrene) (THC : 0...15 ppm, 0...150 ppm equivalent)
Measurement range - microFlu HC 5000PAH : 0...5000 ppb (phenanthrene) (THC : 0...150 ppm equivalent)
Measurement accuraciesenviroFlu HC 500 : 0,3 ppb PAH
enviroFlu HC 5000 : 0,5 ppb PAH

microFlu HC 5000 : 10 % ppb PAH
Response timesenviroFlu HC : T100 < 10 s

microFlu HC : T90 = 6 s
Measurement intervalsenviroFlu HC : < 5 s

microFlu HC : 3 s
Housing materialsstainless steel (1.4571 / 1.4404) or titanium (3.7035)
Dimensions (L x Ø)enviroFlu HC : 311 mm x 68 mm

microFlu HC : 162 mm x 48 mm
WeightsenviroFlu HC : 2,7 kg stainless steel - 1,9 kg titanium

microFlu HC : 650 g stainless steel - 510 g titanium
InterfacesenviroFlu HC : digital RS-232 or analogue 4 ... 20 mA, 0 ... 5 VDC

microFlu HC : digital RS-485, Modbus RTU or analogue 4-20 mA, 0 ... 5 VDC, 0 ... 10 VDC
Powers supply and consumptionsenviroFlu-HC : 12 ... 24 VDC, < 3,5 W

microFlu HC : 12 ... 24 VDC (+/- 10%)
MaintenancesenviroFlu-HC : < 0.25 h / month (optical window cleaning)
microFlu HC : < 0.5 h / month (cleaning the optical window)
Calibration interval24 months
Pressures max.- with waterproof connector SubConn : 30 bars
- with fixed cable : 3 bars
- in flow cell : 1 bar, 2 ... 4 L/min
Medium / sample temperature+2 ... 40 °C
Inflow velocity0,1 ... 10 m/s
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