of bolting alloys. Recalibration of the tension measuring is possible, but often

The use of bolt extension measurement can significantly improve the reliability of the bolted connections. Most direct length-measurement systems will ensure accurate bolt tensioning provided the user pays attention to the fundamentals:

100% calibration Assured datum points Good records Ensured grip/gage length Trained personnel Environmental impact

Where traditional direct length-measuring systems and procedures have not been successful, one or more of the above points have not been addressed.