摘要 |
A method of detecting oil aerosol in an air flow. The contaminated air is passed between an electrode (11) and an electrically conductive catalyst (14), and an electrical discharge therebetween causes electrostatic precipitation of oil on to the catalyst. Air flow and discharge are stopped, and the catalyst is heated with the air substantially stagnant until the catalytic combustion temperature of the oil is reached. The heat generation due to such combustion is sensed and used to produce an output signal indicative of the quantity of deposited oil. |