To control the bolt force applied during assembly, we measure the bolt elongation - elongation and force are related by calibration.
In our application, bolt elongation is measured using a bolt with an internal pin. This pin is connected to one side of the bolt, the other end is free. When loaded, the pin length remains constant and the bolt is elongated. A dial gauge at the end of the bolt measures the diffence between bolt end and pin, i.e. bolt elongation.
The dial gauges are set directly on the clamping fixture's tension nuts. They measure the bolt elongation throughout the entire clamping process.
Bolt elongation can be read directly at the integrated digital indicators.
This enables individual bolt forces to be adjusted precisely to almost any level desired.
As an option the data can be transmitted wireless to a data logging system, giving the possibility to show graphs of the resulting bolt stress levels.
All stages of the clamping process can be seen online on the screen.
At the end of the clamping process, the quality of the assembly can be documented with a report.