The Elcometer NDT BG80TDL Bolt Tension Monitor is an ultrasonic gauge that measures the actual tension in a fastener by measuring how much the bolt elongates as it is tightened. When a nut is tightened under load, the bolt stretches, and the Elcometer NDT BG80TDL Bolt Tension Monitor measures that elongation to report time in nanoseconds, elongation, load, stress and percentage strain. The reason this matters is that standard torque techniques are distorted by friction and resistance, so two bolts tightened to the same torque can carry very different loads, leaving joints under or over tensioned.

Because it works by ultrasonics, the Elcometer NDT BG80TDL Bolt Tension Monitor is not affected by temperature, friction or resistance, giving accuracy within 0.0001mm with a resolution of 0.0001mm. The Elcometer NDT BG80TDL Bolt Tension Monitor operates in Pulse Echo and PE with Gate modes over a measuring range of 254 to 1370mm, with a velocity calibration range of 1250 to 10,000 m/s and a single element transducer covering 1 to 10MHz. Using the gauge's RS232 interface together with the optional shut off accessory, the tightening process can be programmed to stop automatically once the correct load has been reached.

The Elcometer NDT BG80TDL Bolt Tension Monitor stores 8,000 readings and waveforms in multiple groups, offers Hi/Lo alarm limits and an Auto Set feature, and runs for around 150 hours on three AA batteries in a sealed, waterproof aluminium case. Used for critical bolted joints in fabrication, structural and plant work, the Elcometer NDT BG80TDL Bolt Tension Monitor is supplied by BAMR, South Africa's authorised Elcometer distributor.