Patent ID: 8776553

Claim:
An automatic clothes washer, comprising: an imperforate tub; a perforated drum located within the tub and defining a laundry chamber for receiving a laundry load; a water level sensor associated with the tub for detecting a water level in the tub; a water supply system configured to supply water into the tub; and a controller operably coupled to the water level sensor and the water supply system and configured to: supply water to the tub with a laundry load in the tub to form a mixture of water and laundry and, during the supply of water, repeatedly defining a water level window within the tub to define a plurality of water level windows, wherein each of the plurality of water level windows is defined between a lower water level and an upper water level, and wherein at least one of the lower or the upper water levels moves upwardly in the tub; determine a value indicative of a relative density of the mixture that is based on a transient density of the mixture within at least one of the plurality of water level windows based on an amount of water supplied within at least one of the plurality of water level windows; compare the value indicative of a relative density of the mixture to a reference value stored in a memory accessible by the controller and provide as output a value indicative of a load size based on the comparison; and determine a load size of the laundry load based on the output.