GB740037A - Improvements relating to rotary fluid flow measuring apparatus - Google Patents

Abstract

740,037. Measuring fluid flow. GENERAL ELECTRIC CO. March 22, 1954 [March 24, 1953], No. 8340/54. Class 40(1) [Also in Group XXVI]. In a rotary fluid meter the fluid in being accelerated radially out through .an impeller causes the impeller to experience a torque which is evidenced as a small angular deflection of the impeller from its mean position; this deflection being proportional to the mass of fluid flowing per unit time is translated into and measured as a variation in an A.C. bridge circuit. The ends of the arms 7 of the impeller have magnetic material members 23, 24 which move between coils 32, 29, 30, 31 with cores 26, 25, 28, 27 respectively. The coils 30, 29 are connected in one arm and the coils 31, 32 in another arm of the A.C. bridge as in Fig. 3 where the remaining two arms and an indicating in. strument such as a galvanometer are rep resented by 37. A deflection of the impeller arms 7 causes the impedences of the two arms containing the coils 29, 30, 31, 32 to be varied in opposite senses causing a differential effect. When the direction of flow of the fluid is reversed the deflections are in the opposite sense. In a modification (Fig. 4, not shown), a permanent magnet rotor is deflected inside an annular core having a polyphase tapped winding which is connected to a like wind ing on a similarly constructed repeater unit, the rotor of which actuates a pointer.