| 释义 |
Weston|ˈwɛstən|
The name of Edward Weston (1850–1936) English-born electrical engineer, used attrib. a. In Electr., designating a primary cell with electrodes of mercury and of cadmium amalgam and electrolyte of cadmium sulphate, used as a standard voltage source for calibrating electrical instruments.
1901[see metastability]. 1963G. L. Pickard Descriptive Physical Oceanogr. vi. 94 The Weston cell has a limited sensitivity. 1972Physics Bull. Jan. 40/2 The Bureau is..interested in the Josephson effect for possible use in electrical standards, although for the moment the standard Weston cell is preferred for convenience.
b. In Photogr., designating an obsolescent system of film speeds based on exposure meters made by the Weston Electrical Instrument Company or its successors.
1940Chambers's Techn. Dict. 905/2 Weston film⁓speed. 1950W. F. Berg Exposure 167 The introduction of Weston speed figures was of considerable importance. 1963Jerrard & McNeill Dict. Sci. Units 105 The Weston number, the British Standards Institute speed number and the American Standards Association system also indicate the speed of the emulsion at its maximum sensitivity. |