摘要 |
In a flow sensing device in which flow is measured by the linear displacement of a moveable bobbin within a throat, the bobbin contains a cylinder and piston arrangement, with the piston linked to the same linear displacement sensing device as the bobbin. Fluid pressures upstream and downstream of a calibrated orifice parallel to the throat, is applied to opposite ends of the piston. Low flow rates are measured by the displacement of the piston, with movement of the bobbin together with the piston taking over the flow sensing function at higher flow rates. |