E 1951-02 对十字线和光显微镜放大倍数校准的标准导则.PDF

Designation: E 1951 – 02 Standard Guide for Calibrating Reticles and Light Microscope Magnifications1 This standard is issued under the fixed designation E 1951; the number immediately following the designation indicates the year of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A superscript epsilon () indicates an editorial change since the last revision or reapproval. 1. Scope 5. Procedures 1.1 This guide covers methods for calculating and calibrat- 5.1 Nominal Magnification Calculations : ing microscope magnifications, photographic magnifications, 5.1.1 A calculated magnification, using the manufacturer’s video monitor magnifications, grain size comparison reticles, supplied ratings, is only an approximation of the true magni- and other measuring reticles. Reflected light microscopes are fication, since individual optical components may vary from used to characterize material microstructures. Many materials their marked magnification. For a precise determination of the engineering decisions may be based on qualitative and quan- magnification observed through an eyepiece, see the procedure titative analyses of a microstructure. It is essential that micro- describe in 5.5. scope magnifications and reticle dimensions be accurate. 5.1.2 For a compound microscope, the total magnification 1.2 The calibration using these methods is only as precise as (Mt) of an image through the eyepiece is the product of the the measuring devices used. It is recommended that the stage