Method and appliance for detecting oil or petrol in water

摘要

The method for detecting oil or petrol in water employs a capacitive probe which responds to the different permittivity of water and oil or petrol and which is dipped into the water surface at intervals. In each case, the measurement is performed immediately after immersion. If the oil percentage is very small in proportion to the amount of water, a separation vessel is used through which part of the water to be monitored is passed. In this case, the probe is arranged at the separation vessel. Repeated immersion of the probe into the water surface is achieved by repeated fluctuations of the water level in the separation vessel. The method is particularly suitable for monitoring cooling water of oil-cooled transformers.