A method for producing an arc detection signal on the basis of a plurality of observation signals comprises producing an arc detection part-signal for each of at least two observation signals. Producing each of the part-signals includes correlating the respective observation signal with a correlation signal by influencing the correlation signal with the respective observation, thereby producing a correlation result; producing or modifying a coefficient on the basis of the correlation result; and weighting the respective observation signal with the coefficient. The arc detection part-signals are added to form the arc detection signal.