Dakota Bolt Tension Monitor Transducers are a full range of ultrasonic probes that work with Dakota's BT1-DL and BT2-D bolt tension monitors to measure the actual elongation produced when a threaded fastener is tightened. Torque-based tightening is affected by friction and thread condition, so two bolts torqued identically can carry very different loads. Measuring elongation removes that uncertainty and gives a direct reading of the clamp force on each fastener.

The transducers work by sending an ultrasonic pulse along the fastener and measuring the change in its length under load. Within the elastic limit of the fastener, that change in length is proportional to the applied load, so knowing the physical properties of the fastener allows the load to be calculated from the measured elongation. The range covers 2.25MHz, 5.00MHz and 10.00MHz frequencies in single element contact and single element magnetic configurations, with probe diameters from 1/8 inch up to 3/4 inch and Microdot connection.

Magnetic versions hold themselves to the bolt head, while non-magnetic contact types use finger tip and slim finger tip styles for tight access. Damping is specified per part: R for resolution damped, S for standard undamped and H for highly damped. These transducers are used in bolted assembly and structural fastening work across sectors such as wind energy, automotive, bridges and heavy structures. Supplied by BAMR, South Africa's authorised distributor.