| 摘要 |
PURPOSE:To take measurements precisely even when an air blower is used for a variety of piping by providing a suction pipe with a by-pass air conduit wherein a very small amount of by-pass air flows, installing a fine flow rate detector which generates an output in response to the extremely small amount of air in the middle of the air conduit, and detecting a by-pass flow rate and measuring air capacity. CONSTITUTION:A hot-wire type resistor 23 is installed as a fine flow rate detecting means in the by-pass air path 20; one terminal of a static pressure pipe 21 communicates with the by-pass air conduit 20 and the other terminal 24 is open in a direction (non-blast direction) perpendicular to the air blast direction of the suction pipe while piercing a bracket 26. One terminal of a total pressure pipe 22 communicates with the by-pass air conduit 20 and the other terminal pierces the bracket and is open in the air blast direction of the suction pipe 3 through an opening part 25. An expanding constitution means 27 which expands the size of the total pressure pipe 22 is provided in the total pressure pipe 22. Further, a by-pass flow passage control means 28 which has its draft area much less than that of any other airway, specifies the by-pass air capacity, and adjusts and controls the by-pass air rate is provided to any of the by-pass air conduit 20, static pressure pipe 21, and total pressure pipe 22. |
