PROCEDE DE COMMANDE D'UN ARC FLAMME LORS DE LA COUPE ET DISPOSITIF POUR LA MISE EN OEUVRE DUDIT PROCEDE

To control the plasma arc in accordance with the present invention, the pressure change characteristics or curve in a torch is determined from the moment a plasma forming gas is delivered thereto until this plasma forming gas reaches the pressure in the supply manifold. Such a measurement is done for each selected cutting condition characterized by a constant flow rate of the plasma forming gas. The arc supply current is then fed in two stages: at first by a jump to a current amounting to approximately half the cutting current for a selected condition and then by gradually increasing the current in compliance with the pressure change characteristics or curve until the cutting current value is attained. Also described is a device to realize the method, comprising a torch pressure sensor, a means for shutting off the torch nozzle, a memory unit registering the signals of the pressure sensor and a rectifier regulator control means which controls the regulator in accordance with the sensor signals recorded in the memory unit.