Abstract: In a flowmeter for measuring fluid flow, fluid passes through a primary element (20) in which the pressure on respective sides of the restriction (2a) acts on respective sides of the diaphragm (11) mounted in a diaphragm housing (3). The diaphragm, in turn, acts on a measuring element (17) provided with strain gauges (27) connected to a measuring bridge (5). The signals from the measuring bridge (5) can be used to indicate the flow through the orifice plate, for example, on an indicating instrument (7), or otherwise to record changes in the flow or control the flow to a desired value by means of a control system.