KRABO® technology monitors the fastener tension with the ultrasonic technique. This technique is a gold standard for measure clamping force in a bolted joint.

How does it work?
The clamped fastener elongates proportionally to the clamping force applied. KRABO® developed a smart equation to precisely determine from the fastener elongation its tension, expressed in KN.

How do we measure the bolt length?
Ultrasound pulses travels all along the body of the fastener. KRABO® estimates the actual length of the bolt measuring the time passed between one sound pulse and its echo received from the end of the fastener.