The Heron Oil Watch is a device used to prevent oil that has accumulated in catchment tanks that are being drained into groundwater and surface water systems.
When the floating oil layer approaches the tank outlet, the Oil Watch sends a signal (mA) to the P.L.C. warning of impending oil release or pump/valve closure.
When the oil layer reaches the outlet, the signal changes, indicating oil release occurring and/or the pump/valve being closed.
When the oil level rises due to the inflow of water, the pump/valve remains closed until the oil layer has reached the top sensor. At this stage the pump/valve is re-opened.
In the event of a power failure or the failure of both sensors in the probe, the Oil Watch defaults to fail safe (pump/valve closed).