| 摘要 |
Instead of providing a channel in a Pitot tube for measuring static pressure, a channel is provided which terminates in an orifice facing perpendicular to the direction of the flow to be measured, surrounded by a rim having a surface, which may be quite narrow, that is inclined at between 15 DEG and 45 DEG , preferably 30 DEG , to the plane perpendicular to the axis of the orifice, in order to intensify somewhat the Bernouilli effect of the flow across the orifice. This produces a suction (reduction of pressure) approximately equal to the increase of pressure sensed at an upstream facing orifice of a second channel produced by the same flow which is being measured. A differential manometer connected to the two channels registers about twice the pressure difference that would be measured between the pressure at an upstream facing orifice and the pressure in a channel that measures merely the static pressure in the flowing medium.
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