Borehole Micrometer
The Borehole Diameter Caliper is a mechanical micrometer used to measure roof-bolt-hole diameter along its length, with a stainless-steel body, expandable arms and a calibration ring to check accuracy over time.
- Range
- 25-55 mm standard (30-60 mm version also available)
- Insertion depth
- Up to 3 m from the borehole opening
- Body
- Stainless steel, replaceable brass slider and jaws
Overview
In detail
How it works
Three expandable arms take a precise diameter reading with a smooth pull-to-measure mechanism, and a calibration ring is supplied to check accuracy over time. The stainless-steel body has replaceable brass sliders and jaws, with millimetre gradations on both sides of the handle, and it's mine-tested for robustness.
Range
The standard unit measures 25 to 55mm in diameter, with a larger 30 to 60mm version also available, and can be inserted up to 3 metres from the borehole opening on a highly flexible cable.
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Specifications
Technical specifications
- Range
- 25-55 mm standard (30-60 mm version also available)
- Insertion depth
- Up to 3 m from the borehole opening
- Body
- Stainless steel, replaceable brass slider and jaws
- Graduations
- Millimetre gradations on both sides of the handle
Downloads
Documentation, openly available
Everything you need to specify, install and integrate the Borehole Micrometer — no login, no paywall.
Related
Often specified alongside
ESS Earth
Resistance Wire Extensometer RWE
- Application
- Underground hard rock and coal mine displacement monitoring
- Monitoring points
- Pillars, stope walls, roof
Geosystems
JM Series Vibrating Wire Jointmeter
- Range
- 25, 50, 100, 150, 200, 250, 300 mm (200/250/300 mm not available for JM-E)
- Accuracy
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