Abstract: A method of measuring aircraft fuel quantity and density in a fuel container using an ultrasonic transducer; a stillwell liquid fuel; a computer control, an indicator and an altitude sensor. The computer control includes a central processing unit connected to each of the ultrasonic transducers. The altitude sensor is connected to the central processing unit. The indicator means is connected to the central processing unit. The stillwell is supported by the container. Each ultrasonic transducer is supported within the stillwell by the container. The liquid fuel is supported within the container. An ultrasonic signal is transmitted from the transducer within the stillwell. The reflected ulrasonic signal is received by the transducer within the stillwell. The round-trip time period from sending to reciving the signal is measured. The quantity of fuel in the container is determined from the round-trip time period and stored data on the container volume in the central processing unit.

Abstract: Method and apparatus for detecting the presence of liquid in a container includes an elongate rod (or other vibratory element) which extends into the container to contact liquid when a certain amount of liquid is present, a piezo-electric element coupled to the rod on the exterior of the container to cause the rod to vibrate in response to electrical signals and to produce electrical signals indicative of the amplitude of vibration of the rod, and circuitry for producing a utilization signal when the electrical signals produced by the piezo-electric element indicate that the amplitude and duration of vibrations of the rod are below some threshold level. Such vibrations fall below the threshold level when the rod contacts liquid in the tank and so production of the utilization signal is an indication that liquid in the container has reached a certain level.

Abstract: A dry film processor includes a housing, a film supply canister disposed in the housing for holding film and supplying it to the other processing apparatus, a take-up canister also disposed in the housing for receiving and holding the film after it has been processed, storage apparatus for receiving film from the supply canister and for supplying the film to the take-up canister, a drive roller for moving the film from the supply canister to the storage apparatus at a speed determined by certain input speed signals, heater apparatus for heating the film to enable development thereof, drive belt apparatus responsive to control signals for moving the film to withdraw it from the storage apparatus and move it past the heater apparatus, and a control unit for supplying control signals to the drive belt apparatus.