Dakota Calibration Blocks are reference standards used to calibrate Dakota ultrasonic thickness gauges and flaw detectors so that their readings can be trusted. An ultrasonic gauge measures thickness by timing a sound pulse through a material, and that timing depends on the material's sound velocity. Calibrating against a block of known thickness and material lets the operator set the gauge correctly before inspection, which is what makes the resulting measurements accurate.

The blocks are available as a set or individually, so users can pick the most appropriate thickness for their application. Dakota NDT calibration standards are manufactured from 4340 steel to a tolerance of plus or minus 1% of the nominal thickness and are supplied complete with calibration certificates. The range includes 4340 steel five-step (.100 inch to .500 inch) and four-step (.250 to 1.0 inch) blocks, 1018 steel five-step (2.5 to 12.5mm) and four-step (6.25 to 25.0mm) blocks, 3 inch and 6 inch steel calibration bars, a 3 inch steel bar and a glass calibration block in 1 inch, 2 inch and 3 inch.

Selecting the correct block matters: the form, shape and material should be appropriate for the material being inspected, and any artificially induced flaw should closely resemble the actual flaw being tested for. These standards support gauges across the ZX, MX and X ranges, including BT1 and BT2 bolt tension monitors. Supplied by BAMR, South Africa's authorised distributor.