Robustly designed for heavy duty work, it features three expandable arms for precise diameter measurement, is easy to use, and comes with a calibration ring to check accuracy over time.
Data Sheet: Borehole Micrometer
Or newly designed micrometer is a mechanical device used to measure the diameter of a roof bolt hole along its length. The standard unit has a measurement range of 25 to 55mm, with a larger 30 to 60mm version also available. It can be inserted up to a depth of 3 metres from the borehole opening. With a smooth pull-to-measure mechanism, measuring a borehole diameter has never been easier.