TABLE OF CONTENTS This chapter is a selection of methods and techniques for measurements of basic physical variables and selected engineering parameters.
These are made form-hardened and tempered steel marked off with high accuracy in length from about 10-30 cm with folding rules up to 60 cm. They are used for marking off, setting calipers and dividers, etc.
This is used for internal and external measurements. It has a long flat scale with a fixed jaw and a sliding jaw, with a scale, or cursor, sliding along the fixed scale and read in conjunction with it. Two scales are provided to allow measurement inside and outside of the jaws (Fig. 19.1).
Micrometers are used for the measurement of internal and external dimensions, particularly of cylindrical shape. Measurements are based on the advance of a precision screw (Fig. 19.2).
Gage blocks represent industrial dimension standards. They are small steel blocks with highly polished parallel surfaces. Gage blocks are available in a range of thicknesses that make it possible to stack them so than any required dimension can be obtained in increments. Table 19.1 gives sets of gage blocks.
| No. blocks | |
|---|---|
| Set M 78 | |
| 1.01-1.49 mm in 0.01-mm steps | 49 |
| 0.05-9.50 mm in 0.50-mm steps | 19 |
| 10, 20, 30, 40, 50, 75, 100 mm | 7 |
| 1.0025 mm | 1 |
| 1.005 mm | 1 |
| 1.0075 mm | 1 |
