Tool (10) provided with at least one active element (12), comprising a safety device (20) electrically coupled, through a first interface (22), to the active element (12), further comprising the safety device a detector (24, 26, 28) arranged to: - periodically measure, at the level of the first interface (22), a value (M2； MF2) of function of an electrical capacity and of the contact of the active element with a foreign body； - compare the measured value (M2； MF2) with a reference value (REF + S1； REFF + S1) typical of an event； - providing, in a second interface (30), a safety signal (SSEC) comprising information related to said event, when the difference between the measured value (M2； MF2) and the reference value (REF； REFF) is exceeding a threshold (S1), said tool being characterized in that the detector (24, 26, 28) comprises: - a control device (28)； - a signal generator (24), comprising a capacitor having a first capacity (Cs), coupled to the first interface (22), the signal generator being configured to produce a sequence comprising at least one generated pulse - making circulating a current in the capacitor to charge the active element (12) to a first potential (Vcc)； - and then discharging the active element to the reference potential (Gnd)； - a measuring device (26), capable of measuring a voltage at the capacitor terminals； the control device being configured to: - direct the signal generator (24) to produce a number N of repetitions of the sequence until the voltage measured at the capacitor terminals is greater than or equal to a predetermined voltage (U)； - compare the number N of repetitions with the reference value (REF； REFF) specific to the event； - when the absolute value of the difference between the number N of repetitions and the reference value (REF； REFF) exceeds the threshold (S1), provide, at the second interface (30), the safety signal (SSEC) that includes information related to said event.Herramienta (10) dotada de al menos un elemento a
