Abstract: An apparatus for measuring oil droplets and other bodies in a liquid, the apparatus comprising a body having an imaging device mounted therein, said body having a measurement window adjacent a measuring region through which an image of a fluid within the measurement region may be viewed by the imaging device, wherein a light source is provided for illuminating said measurement region, said light source being directed towards the imaging device by a light directing means, the apparatus including an ultrasonic transducer mechanically coupled to the measurement window for removing fouling from the measurement window and for creating cavitation within said measurement region, wherein said light directing means is located in or adjacent said measurement region to be exposed to said cavitation created by the ultrasonic transducer to remove fouling from said light directing means.

Abstract: A method of measuring the amount of a fluorescent material in a liquid comprising the steps of exciting the fluorescent material and measuring the fluorescent response of the material over a range of wavelengths to determine a response spectrum, identifying the material from the response spectrum and determining the amount of material as a function of the amplitude of the fluorescent response and a calibration factor based upon the identification of the material.

Abstract: An apparatus (10) for measuring, in particular, the amount of oil present in a quantity of water. The apparatus comprises a measurement chamber (12) having an optical window (18) through which an excitation signal may be transmitted and fluorescent light may be detected. The apparatus further includes an ultrasonic transducer (34) coupled to the measurement chamber and having a pair of channels (44,45) formed therein, the channels opening onto the measurement window (18). A respective light guide (28) is inserted into each channel, one light guide being arranged to deliver the excitation signal into the chamber through the measurement window, the other being arranged to carry fluorescent light from the chamber.

Abstract: An apparatus (10) for measuring, in particular, the amount of oil present in a quantity of water. The apparatus comprises a measurement chamber (12) having an optical window (18) through which an excitation signal may be transmitted and fluorescent light may be detected. The apparatus further includes an ultrasonic transducer (34) coupled to the measurement chamber and having a pair of channels (44,45) formed therein, the channels opening onto the measurement window (18). A respective light guide (28) is inserted into each channel, one light guide being arranged to deliver the excitation signal into the chamber through the measurement window, the other being arranged to carry fluorescent light from the chamber.