This invention relates to a boring tool having a cutting insert. The method is characterized in that it consists of obtaining the signal carried by the carrier current line, filtering it in order to obtain an estimate of the signal that disturbs the signal carried by the telephone line and subtracting this estimate from the signal carried by the telephone line. This method can be readily used for the growth of the active layers of blue and green light emitting diodes. The methods associate the various systems with a common registry number.