NEN EN ISO 3650 : 1999

1. Scope
2. Normative references
3. Definitions
4. Nomenclature of faces
5. Basis of measurement, traceability, reference
     condition
     5.1 Unit of length: metre
     5.2 Traceability of the length of a gauge block
     5.3 Reference temperature and standard pressure
     5.4 Reference orientation of gauge blocks
6. General dimensions, material properties, marking
     6.1 General dimensions
     6.2 Material properties
           6.2.1 Material
           6.2.2 Coefficient of thermal expansion
           6.2.3 Hardness
           6.2.4 Dimensional stability
     6.3 Marking
7. Metrological requirements
     7.1 General
     7.2 Flatness tolerance, tf
           7.2.1 Gauge blocks with nominal lengths exceeding
                   2,5 mm
           7.2.2 Gauge blocks with nominal lengths up to
                   2,5 mm
     7.3 Measuring faces
     7.4 Side faces
           7.4.1 Flatness
           7.4.2 Parallelism
           7.4.3 Perpendicularity
           7.4.4 Edges
8. Calibration of gauge blocks
     8.1 General
     8.2 Wringing test
     8.3 Measurement by interferometry
           8.3.1 Measured length
           8.3.2 Auxiliary plate
           8.3.3 Corrections to measurements by
                   interferometry
           8.3.4 Calibration certificate
     8.4 Measurement by comparison
           8.4.1 Principle of measurement
           8.4.2 Central length
           8.4.3 Method of determining length by comparison
           8.4.4 Variation in length
           8.4.5 Corrections
           8.4.6 Calibration certificate
Annex A (informative) Example of a device for the comparison
of gauge blocks
Annex B (informative) Relation to the GPS matrix model
Annex C (informative) Bibliography

Defines the most important design and metrological characteristics of gauge blocks with a rectangular cross section and a nominal length ranging from 0,5 mm to 1 000 mm. Limit deviations and tolerances are stated for the calibration grade K and for the grades 0, 1 and 2 for various measuring purposes.