Sensitive mercury-level detecting unit for manometers
Bill Williams · Journal of research of the National Bureau of Standards · 1952
An electronic in strument has been developed to determine the differential heigh t of t he two arm s of a m ercury manometer.The instrument has a sensitiv ity corresponding to O.0005-inch height differential, and the pick up units are designed to prov ide t his performance at absolute press ures up to 3.5,OOOpounds per square inch .Use is made of a high-frequency mu tual-Illduc tance mIcrometer , WIth the tops of the mercury colu mn s serving a s t he reference surfaces.