| 释义 |
▪ I. pitot1 rare.
[Origin obscure: cf. piddock.]
app. A razor-shell. (See also quot.1971.)
1611Cotgr., Manche de cousteau, the Pitot; a long, and round shell-fish. 1971A. M. Lysaght Joseph Banks in Newfoundland & Labrador 1766 vii. 161 These molluscs [sc. Cyrtodaria siliqua] are known by the French name of ‘pitot’ and the areas where they live are called ‘pitot banks’.
▪ II. pitot2 Physics and Aeronaut.|ˈpiːtəʊ|
Also Pitot.
The name of Henri Pitot (1695–1771), French scientist, used to designate devices based upon his inventions for measuring the relative velocity of a fluid, esp. the airspeed of an aircraft, as pitot head, a pitot-static tube; pitot-static a., designating a device consisting of a pitot tube inside or adjacent to a parallel tube closed at the end but with holes along its length, the pressure difference between them being a measure of the relative velocity of the fluid; also absol.; pitot († or Pitot's) tube, an open-ended right-angled tube pointing in opposition to the fluid flow and connected to a means of measuring pressure; also, a pitot-static tube; also absol.
1881Encycl. Brit. XII. 508/1 A Darcy gauge..consists of two Pitot tubes having their mouths at right angles. 1895R. C. Carpenter Heating & Ventilating Buildings ii. 38 In case the pressure and velocity are great, considerable error will be made by using the open tube.., and for such a case a Pitot's tube..should be used. 1901G. E. Davis Handbk. Chem. Engin. I. iv. 191 The total pull of a chimney upon a water manometer when only one limb of the tube was connected up, was 14/16 of an inch, while with the Pitot tube the amount shown was only 8/100 of an inch of water. 1914Techn. Rep. Advisory Comm. Aeronaut. 1912–13 59 This pressure-tube anemometer consists of two tubes, a Pitot tube facing the wind and a static pressure-tube along the wind direction with holes drilled into the side of it. 1916Field 20 May 788/2 At last he fumbles for his safety belt, but with a start remembers the Pitot Air Speed Indicator, and..smiles as he hears the Pitot-head's gruff voice, ‘Well, I should think so, twenty miles an hour I was registering.’ 1920G. C. Bailey Compl. Airman xxi. 172 The only really satisfactory test of the Pitot is a flying one. 1920L. Bairstow Appl. Aerodynamics iii. 75 (heading) Initial determination of the constant of the pitot-static pressure head. 1930C. J. Stewart Aircraft Instruments iii. 54 The pitot-tube instrument is based on an adaptation of the method used by Pitot in 1732 for the measurement of the speed of a river. 1934V. M. Yeates Winged Victory I. iii. 27 Looking at the pitot he found the speed was a hundred and twenty. 1942R.A.F. Jrnl. 27 June 21 One [Gremlin]..was seen..to swing nimbly..down to the pitot head and block it with ice. 1948Jrnl. R. Aeronaut. Soc. LII. 272/1 Rates of climb and descent measured by the pitot-static are subject to errors introduced by random vertical currents in the atmosphere. 1965R. G. Kazmann Mod. Hydrol. iv. 63 The Pitot tube can be used to make a pattern of measurements along the cross section of a stream. 1973‘A. Hall’ Tango Briefing ix. 111 His inability to know to what extent our airspeed would be true and to what extent it would be expressed by the wind in the pitot-head. 1975L. J. Clancy Aerodynamics iii. 25 The pitot-static tube may be mounted in a position on the aircraft where the flow is affected by the presence of the aircraft. 1978R. V. Jones Most Secret War iv. 36 This is true enough of a pitot tube but, as Lindemann pointed out to me, the proposal was perfectly sound if one used, as the inventors suggested, accelerometers.
b. Pitot meter, also pitometer |pɪˈtɒmɪtə(r)|. (See quots. 1934, 1941.)
1907Jrnl. Franklin Inst. CLXIV. 440 It is only necessary to leave the pitometer orifices at the point of maximum velocity in order to record the mean flow. 1934J. H. Perry Chem. Engineers' Handbk. 692 The pitot meter consists of two tubes, one facing upstream and the other downstream. 1941Ibid. (ed. 2) 838 The modified pitot tube known as a pitometer has one pressure opening facing upstream and the other facing downstream. The differential between the two openings is usually from 25 to 50 per cent more than that for a standard pitot tube. 1955C. S. Forester Good Shepherd ii. 25 That was the pito⁓meter log reading. 1961Engineering 3 Nov. 566/3 The development flowmeters..were calibrated in clean air against a venturi meter and a pitot meter. |