Weighing apparatus and method. A plurality of weigh members are moveable in sequence in a continuous path. Each weigh member receives an item to be weighed and includes a member which is moveable in response to the weight of the carried item. Preferably, the moveable member is elastically deformable. When an item to be weighed is deposited on a weigh member, the moveable member moves in response to the weight and then "springs" back and so on in an oscillating fashion. The weigh members, each carrying an item to be weighed, are rapidly moved in sequence along the continuous path to a weighing location and the time, while short, is sufficient to permit oscillating movement of the moveable member to substantially cease by the time that the weigh member arrives at the weighing location. At the weighing location, electromagnetic radiation is impinged upon a boundary edge of the moveable member and a pattern of electromagnetic radiation is produced which is characterized by the position to which it moved in response to the weight of an item carried by the weigh member. In a preferred embodiment, the electromagnetic radiation is impinged upon two boundary edges, one fixed and one moving with the moveable member. Diffraction waves emanating from the boundary edges interact to form an interference pattern and the interference pattern is characteristic of the position of the moveable boundary edge relative to the fixed boundary edge. The pattern is analyzed to determine the weight of an item borne by each respective weigh member.