The first fully wireless KRABO® prototype is a series of M24 structural bolts HV 10 ranging from 80 mm up to 115 mm in length. KRABO® technology is embedded in the bolt head. Each bolt contains an electronic device designed to monitor in real time the tension of the bolt. A battery is embedded into the device to power-up the system without any external cable. The device also implements an RF transmitter to communicate the tension measured to a remote wireless receiver unit.

No human intervention is needed.

After the installation and the first power up, the KRABO® bolts do not require any further intervention. The bolt itself starts periodically to send its tension status to the remote unit. The operator may check the tension of each KRABO® bolts at any time from a software interface.

KRABO® plug protects the bolt head from climatic effects.

The removable plastic plug is added to the bolt to better secure from climatic effects the KRABO® technology in this prototyping phase. The plug reports the HV 10.9 prints on its top to conform with regulations.

Reliable monitoring of bolt tension in real time.

In the laboratory the prototype of the networking bolt is tested under a controlled load. The measure is compared to a reference load cell. In the test set-up, the KRABO® bolt autonomously provides one sample every two minutes. In this configuration, the prototype is tested for one night and 24 hours on a static load. The comparison reported a maximum measurement error of around 1%.