BS 887:2008 specifies requirements for the construction, for the accuracy at the reference temperature of 20 °C and for the protection of metric and imperial precision vernier callipers with external and internal contact faces.
BS 887 specifies requirements for metric callipers to measure lengths up to a maximum of 1 000 mm using a main scale and a vernier scale graduated to read to 0.02 mm and for imperial callipers to measure lengths up to a maximum of 48 in using a main scale and vernier scale graduated to read to 0.001 in.
BS 887 does not specify full requirements for callipers with an electronic display, although the requirements for the beam, slider and measurement faces may be the same as the vernier calliper.
BS 887 has been revised to bring it up to date. Because industry still has a need for imperial callipers, this revision specifies requirements for both metric reading and imperial reading instruments. It includes requirements for a single design of vernier scale which can have graduations either in metric or in imperial units.
BS 887:2008 supersedes BS 887:1982, which is withdrawn.