On-line water analysis often places heavy demands on sample filtration. Aside from the expected high availability of the analysis system in conjunction with low maintenance requirements, defined filter characteristics must be assured.The sample filter system manufactured by LFE helps meet these requirements using a cross-flow filter element. The filter element is irradiated at adjustable, regular intervals by ultrasonic energy. The ultrasound generator (approx.40 kHz) creates cavitation in the water sample which serves as the coupling medium. The implosions of a tremendous number of micro cavitation bubbles results in the familiar excellent cleaning effect. The particles loosened from the filter element are carried away by the main sample stream.The filtered sample can be taken continuously from the cleaned filter element.LFE's sample filter consists of the filter unit containing the ultrasonic transducer and a control unit with the timer controlled ultrasound generator. The control un