National Physical Laboratory

Angle measurement: Autocollimators, polygons, angle gauges and index tables

Indexing Tables 1

NPL offers a calibration service for a number of types of angle standards.

Although there are many different types of industrial requirements involving accurate angular measurement, only types of work listed below are normally dealt with by NPL. However, other special purpose standards or components requiring precise measurement of angle will be considered on application to NPL.

The basic standards for angle measurement used by NPL depend either on the accurate division of a circle or on the generation of a known angle by means of a precision sine-bar. Several methods are available for dividing a circle but the one employed by NPL for undertaking measurements for the precision engineering industry is based on the accurate meshing of two similar sets of uniformly spaced vee-serrations formed in the top (rotatable) and base (fixed) members of an indexing table.


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Last Updated: 18 Aug 2015
Created: 5 Sep 2007


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