Abstract: A receptacle counting system includes an ultrasonic sound wave transducer for emitting ultrasonic sound waves and for receiving ultrasonic sound waves reflected from a receptacle whose contact level is to be sensed. There is a rim detector, responsive to the reflected ultrasonic sound waves, for determining the location of the rim of the receptacle and a receptacle detector, responsive to the rim detector, for indicating when a receptacle is present. One or more counters, responsive to the receptacle detector, are provided for monitoring the number of receptacles presented to the system.

Abstract: A level sensing system including ultrasonic sound wave transducer means for emitting ultrasonic sound waves and for receiving ultrasonic sound waves reflected from a receptacle whose content level is to be sensed; a content level detector, responsive to the reflected ultrasonic sound waves, for determining the level of the contents of the receptacle; a rim detector, responsive to the reflected ultrasonic sound waves, for determining the location of the rim of the receptacle; and a level comparator, responsive to the rim detector and the content level detector, for comparing the content level with the rim location for indicating when the content level and the rim location are a predetermined distance apart.