IS 6987 : 1973 Specification for Steel Precision Polygons
| UDC 531.747 : 513.19 : 621.753 - 3 | PGD 25 |
|
| Reaffirmed 2014 |
1 Scope
Covers requirements for steel precision polygons of regular formdesigned for use with in autocollimator in measurimg angulardisplacements.