Patent ID: 8226823

Claim:
A flow sensor for a water softener system including a brine tank containing a brine solution, the flow sensor being mounted in the brine tank and comprising: a housing; a first pair of detectors in said housing; a second pair of detectors in said housing, said second pair of detectors being spaced from said first pair of detectors; a movable float located in a cavity defined by said housing; a timer in communication with said first pair and said second pair of detectors, wherein said timer is started when said float moves a designated distance below said first pair of detectors, and wherein said timer stops when said float is detected by said second pair of detectors; a controller in communication with said first pair of detectors, said second pair of detectors and said timer, and configured to start said timer when said float moves the designated distance below said first pair of detectors and stop said timer when said float is detected by said second pair of detectors, said controller configured to determine a first brine solution velocity above said second pair of detectors and a second brine solution velocity below said second pair of detectors based on a difference in time between when said timer started and when said time stopped, and a velocity ratio between said first and said second brine solution velocities; and at least one indicator on said controller, said indicator configured to indicate a probability of a salt bridge based on said velocity ratio determined by said controller.