Surfaces and their Measurements
This book is primarily intended to help designers and inspectors to understand the fundamentals of surface metrology and, where appropriate, point to relevant procedures for specification.
TABLE OF CONTENTS Surfaces and their Measurements
Chapter 14: Calibration of Instruments
14.1 General
Calibration of roughness and roundness instruments is difficult because of the small size and special nature of the features being measured. The difficulties have been recognized for some time and have led to an extensive use of carefully prepared standard specimens. These will be outlined in Section 14.1 and then given in more detail later in the text in addition to some specialized procedures.
14.1.1 Calibration specimens for roughness
There are a number of standards concerning this area, including ISO 5436 for documentation.
| ISO 468 | Roughness - parameters. |
| ISO 1878 | Classification of instruments and devices for the measurement and evaluation of the geometrical parameters of surface finish. |
| ISO 1879 | Instruments for the measurement of surface roughness by the profile method - vocabulary. |
| ISO 1880 | As above - contact (stylus) instruments of progressions profile. Transformation - profile recording instruments. |
| ISO 3274 | As above - contact profile meters, system M. |
14.1.2 Types of calibration specimens [14.1]
To cover the range of requirements, four types of specimens are described. These are:
Type A - for checking vertical magnification
A1 Wide calibrated groove with flat bottom, or a number of separated grooves of equal or increasing depth. The groove has to be wide enough to be insensitive to the condition of the stylus.
A2 As A1 but with rounded bottom.
Type B - for checking the stylus tip
B1 Number of separated grooves proportioned to be increasingly sensitive to the dimension of the stylus. These are for...
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