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PAH probe

Hydrocarbons monitoring in water

Sonde HAP

Either for control wastes or spot a pollution in natural environment, hydrocarbons monitoring in water became a public authoritie's priority. Our energy consumption as well as the increase of industrial production build-up hydrocarbons pollutions in water. In front of these problem affecting health and environment, it is mandatory to strengthen detection in natural environment. The respect of the standards has as an objective to secure a good chemical condition of surface water.

The PAH probe is a fluorometer that measure accurately Polycyclic Aromatic Hydrocarbons (PAH) concentration in water. These PAH are coming from incomplete combustion of organic matter and they exist in most of the mineral oil or fuels. The probe allows to monitor PAH in resources, industrial waste waters production or even in sewage waters.

The UV fluorescence measurement principle used is much more sensitive than the conventional infrared scattering or absorp- tion method. The sensor is able to detect any trace of PAHs in re- source water or in cooling water condensates, for example.

This immersible probe operates without sampling and requires no on-site calibration. The only maintenance operation is to re-ca- librate the probe every 2 years and to replace the excitation lamp after 4 years of use.

Hydrocarbon monitoring in water

The sensor has many accessories to optimize its integration in pro- cesses, manholes or to monitor water level variations, automate cleaning and facilitate the exploitation of the data. Measurement campaigns and mobile applications are also possible with an op- tional battery operating system.

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Measurement principle

UV fluorescence

A xenon lamp emits broad-spectrum light flashes through an optical filter (254nm). This wavelength is guided at the probe outlet to form a UV cone of about 10 centimeters in length in front of the probe.
This excitation light at 254 nm makes it possible to fluoresce the PAHs passing in front of the probe. The light emitted by this fluorescence, at 360 nm, is detected and measured by a photodiode and an optical filter even at low concentrations and in turbid waters. The PAH sensor measures with a reference photodiode the intensity of flashes emitted in order to automatically compensate for lamp power loss over time.


  • Monitoring drinking water resources
  • Biological wastewater treatment plants protection
  • Control of industrial discharges
  • PAH measurement in process water


  • In situ measurement, no sampling no reagents
  • Direct analog output (4-20 mA) without external transmitter
  • Optical window with coating to minimize clogging
  • Real time measurement
  • Automatic compensation of lamp power loss
Principle of measurementfluorescence, xenon flash lamp + 254 nm filter
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 500PAH : 0...500 ppb, 0...5000 ppb (phenanthrene) (THC : 0...15 ppm, 0...150 ppm equivalent)
Measurement accuracyenviroFlu-HC 500 : 0,3 ppb PAH
enviroFlu-HC 5000 : 0,5 ppb PAH
T100 response time< 10 s
Measurement interval< 5 s
Housing materialsstainless steel (1.4571 / 1.4404) or titanium (3.7035)
Dimensions (L x Ø)311 mm x 68 mm
Weight2.7 kg stainless steel - 1.9 kg titanium
Interface digital RS-232 or
analog 4 ... 20 mA, 0 ... 5 VCC
Power supply and consumption 12 ... 24 VCC, ≦ 3,5 W
Maintenance≦ 0,25 h/month (standard use - cleaning of the optical window)
Calibration interval24 mois
Pressure 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