Oil in water detectors utilise floating conductive electrodes to detect the thin layer of oil in water. The system is ATEX hazardous area certified for installation in Zone 1 or Zone 2 hazardous areas.
Floating electrodes are designed for use only in pits, reservoirs, pump shafts, separator plants for light liquids (if not classified as Zone 0) or similar areas.
Floating electrodes can only be used to detect the presence of a layer of a light liquid, which is not soluble in water or conductive on a surface of water that is sufficiently calm to allow phase formation.
Alternatively, the electrodes can be used with a conductive liquid, which has a higher specific density than the respective light liquid.
Proper functioning of the floating electrodes is dependent on the detection of the clear separation between the heavy conductive liquid and the lighter non-conductive liquid at various locations including pits, reservoirs, pump shafts and separator plants.
Functioning of the floating electrodes is ensured when used in closed surveillance areas without discharges (pits, reservoirs or pump shafts) and in separator plants in compliance with DIN 1999 for the listed media.
Application tests have shown that an alarm is activated if non-conductive liquids have formed layers of 3mm-10mm thickness on the heavy liquid (e.g. water) to be monitored.
For all other application areas, a test must be performed prior to the desired use to ascertain whether the phase formation and minimum layer thickness of the non-conductive liquid required for exact functioning can be achieved in the operating conditions in question (such as flow parameters or possible dwell times of the light liquid to be detected in the application site).