An arrangement for a rock bolt that is intended to be embedded in grout in a borehole, a method for using said arrangement, and a reinforcement system including such an arrangement. The rock bolt is equipped with a longitudinal tube with a passage, wherein an extended electrically conducting sensor is introduced into the passage of the tube and the sensor is connected with the anchoring end of the rock bolt, a monitoring arrangement designed to be connected to the rock bolt, an electrically conducting circuit is formed through the connection of the rock bolt, the sensor and the monitoring arrangement, wherein the monitoring arrangement includes evaluation means intended to evaluate the presence of changes in the condition of the bolt, and signaling means designed for the signaling of the condition of the bolt.