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Scientific, nautical, surveying, photographic, cinematographic, optical, weighing, measuring, signalling, checking (supervision), life-saving and teaching apparatus and instruments; apparatus and instruments for conducting, switching, transforming, accumulating, regulating or controlling electricity; apparatus for recording, transmission or reproduction of sound or images; magnetic data carriers, recording discs; automatic vending machines and mechanisms for coin-operated apparatus; cash registers, calculating machines, data processing equipment and computers; fire-extinguishing apparatus.
automatic feedback control system for an oil and gas well, namely, a closed-loop system comprised of computer software, computer hardware, rotating control heads, drilling chokes, pressure sensors, temperature sensors, flow meters, and mud pumps, which measures flow rates of drilling fluid into and out of the well and other parameters and controls a choke in an outlet conduit in order to control flow rate of the well and borehole pressure to provide pressure balance control of the well