Patent ID: 8522625
Filing Date: 2013-09-03
Classification: G01F

Abstract:
1. A flow measuring arrangement for measuring flow of a medium through a measuring tube, comprising: at least one constriction located in the measuring tube which effects a reduction of a volume through which the medium flows internally in the measuring tube, and therewith a change in pressure conditions internally in the measuring tube, dependent on dimensions of said at least one constriction and dependent on flow; a pressure measuring system connected to the measuring tube which serves to measure a pressure (Δp, p) dependent on flow through the measuring tube and dependent on the dimensions of said at least one constriction; measuring electronics, which determines flow based on measured pressure (Δp, p) and the dimensions of said at least one constriction; at least one deflectable membrane applied to one of the measuring tube constrictions internally in the measuring tube, wherein deflection of said at least one deflectable membrane effects a change, dependent on an amplitude of the deflection, of a volume through which medium flows internally in the measuring tube; an apparatus for producing a time variable deflection of said at least one deflectable membrane according to a predetermined time-dependent deflection profile; and, a diagnostic system connected to said apparatus and to said pressure measuring system, which determines at least one effect of time-dependent changes of deflection of said at least one deflectable membrane on the measured pressure (Δp, p), and which produces a diagnosis of the functional ability of the flow measuring arrangement based on the predetermined time-dependent deflection profile and effects, as determined by the diagnostic system, of associated time-dependent changes of the deflection of said deflectable membrane on the measured pressure (Δp, p).