Abstract: A foam monitor senses the dissipation of foam within a transparent tube and employs a series of vertically spaced light emitting diodes which are cyclically pulsed to provide repetitive sequential scanning of the tube contents and a series of photo-responsive elements are axially spaced along the diametrically opposite side of the tube and positioned to monitor corresponding intermittent light paths that may be received from the corresponding light emitting diodes. The intermittent light paths are monitored during each scanning cycle to provide a pulse train which is indicative of the relationship between scanned levels containing foam and scanned levels void of foam. The pulses produced over a predetermined number of repetitive scans are totalized to provide an analytical measurement of the foam dissipation qualities for the liquid involved.