| 释义 |
gradiometer|greɪdɪˈɒmɪtə(r)|
[f. gradient n.: see -meter.]
a. Any of various surveying instruments used for setting out gradients or for measuring the gradient of a slope (see quots.).
1899W. G. Bligh Notes on Instruments Engin. Field-Work v. 89 The ordinary type of level is always at a disadvantage when the ground is sloping. To overcome this difficulty..a variation has been made..which permits the telescope to be inclined. One of these is Stanley's Patent Gradiometer, an excellent combination of the level and clinometer. 1940Chambers's Techn. Dict. 384/2 Gradiometer, an instrument for setting out long uniform gradients; it consists of a level that may be elevated or depressed, by known amounts, by means of a vertical tangent screw. 1960H. L. Michael in K. B. Woods et al. Highway Engin. Handbk. ii. 11 Devices called ‘gradiometers’ or ‘inclinometers’, essentially bubble tubes graduated to read either percentage of grade or degree of incline, have been constructed to obtain grade information.
b. An instrument for measuring the gradient of a field, esp. the horizontal gradient of the earth's gravitational or magnetic field.
1929Mining Mag. XL. 272 (heading) The gravity gradiometer. Ibid. 277 On account of its small size and its rapid speed of operation the gradiometer is admirably adapted for use in confined spaces such as underground mine galleries. 1934Trans. Amer. Inst. Mining & Metall. Engineers CX. 383 At right angles to the magnetic meridian..a positive gradient implies that the vertical component of the magnetic field is increasing to the east. In the magnetic meridian, the effective component is that in the magnetic vertical plane through the center of the gradiometer. 1957Encycl. Brit. X. 681/2 In a design by Shaw and E. Lancaster-Jones [of an instrument for the measurement of gravity gradients] the beam system is made irresponsive to ‘curvature’ effects and is called a gravity gradiometer. 1971Sci. Amer. Aug. 70/2 During the time when the moon was inside this region of very steady magnetic fields we sent commands to the instrument that enabled it to function as a gradiometer. |