The detail in designing the principal features of a vernier depth gauge may vary between manufacturers. The accuracy of performance is based upon the quality and precision of the various features, e.g. the accuracy of dividing of the scales, the quality of the graduation marks, the straightness of the guiding edge of the beam, the flatness of the datum face and the measuring face. These are all features that the manufacturer controls in order that measurements made with the gauge are reliable within specified tolerances.
BS 6365:2008 specifies requirements for the construction, accuracy at the reference temperature of 20 °C and the protection of metric and imperial precision vernier depth gauges. It applies to metric depth gauges that measure from zero up to 600 mm using a main scale and vernier scale graduated to read to 0.02 mm. It also applies to imperial depth gauges that measure from zero up to 24 in using a main scale and vernier scale graduated to read to 0.001 in.
Rrecommended minimum dimensions for the beam section are given, along with whilst methods of testing.
BS 6365:2008 supersedes BS 6365:1983, which is withdrawn.
