| 摘要 |
PURPOSE:To act effectively a rectified gas current to a flow rate detecting part without lowering air inhalation efficiency, by providing a wire net for stabilizing gaseous flow on the entrance side of the gaseous flow of a flow rate measuring pipe. CONSTITUTION:Wire nets 19, 20 are provided to each opening part of the air flow entrance side and that of the outflowing side of a flow rate measuring pipe 15. That is, an accidental damage of resistances 18, 19 is prevented by the wire net 19 of the entrance side and also, a rectifying effect stabilizing effectively the flow of air flowing through a detecting part in a measuring pipe 16, is displayed. On this occasion, a pressure loss is restricted sufficiently in a small range because the wire net 19 acts on the section of the pipe 15 having a sufficiently small area in relation to the sectional area of a suction duct 11. Accordingly, a rectified gas current is made act effectively to a flow rate detecting part without lowering the inhalation efficiency by processing in this manner. |
