| 摘要 |
PURPOSE:To maintain measuring accuracy for a long period of time by providing a flow rate measuring circuit which detects and displays the change in the reactance of a reactance coil as a change in current or voltage. CONSTITUTION:A tapered glass pipe 1 having gradually larger inside diameters in an upward direction is connected to an inflow port 2 and an outflow port 3 and a float 4 made of nonmetals is afloat in the pipe 1. A ferromagnetic material of, for example, ferrite or the like is mounted in the upper end part 4a of the float 4 and a printed substrate 5 is adhered in the longitudinal direction on one side surface of the pipe 1. Spiral flexible printed wirings which are dense in the upper part and are elongated longitudinally so as to be coarser gradually in a downward direction are adhered on the substrate 5, whereby a reactance coil 6 is constituted. The change in the reactance of the reactance coil by vertical floating of the float 4 according to flow rates is measured with a flow rate measuring device 7. |
