Abstract: A system and method for monitoring position of a piston within a fluid-actuated cylinder by radiating microwave energy into the actuator cylinder and measuring axial position of the piston as a function of microwave resonances and the frequencies at which such resonances occur. Separate microwave transmitting and receiving antenna probes are mounted on one end cap of the actuator cylinder, which has a fixed diameter and an axial dimension which varies as a function of piston position. The transmitting probe is coupled to an oscillator which is controlled to sweep a predetermined frequency range for generating one or more TM.sub.01q resonant modes within the cylinder cavity. A threshold detector and a peak detector are coupled to the receiving probe for detecting occurrence of cavity resonances. Latches store oscillator control signals associated with occurrence of up to eight such resonance events, with the stored control signals thus being an indication of resonant frequencies.
Abstract: Seat covering designed to protect both the bottom seat cushion and the back seat cushion of the seat of an automotive vehicle. The protective covering comprises a bottom panel for covering the bottom seat cushion and a back panel for covering the back seat cushion. The panels are connected to a take-up reel mounted at the rear edge portion of the seat. The panels are withdrawn from the reel between the rear edge portion of the bottom seat cushion and the back seat cushion to positions of use respectively covering the bottom and back seat cushions.