A system (1000, 2000, 3000) for controlling flow of a gas to a plasma torch of an additive manufacturing device, comprising: a source of an inert gas; a supply manifold in fluid communication with the source of the inert gas; a plasma torch comprising a gas inlet for receiving the inert gas from an inert gas line connected to the supply manifold, and a gas ionizer electromagnetic field for ionizing the inert gas into plasma; sensory kit comprising a temperature measurement unit, a pressure measurement unit, and a mass flow measurement unit, wherein each unit is in communication with one or more sensory connecters connected to a position of the inert gas line between the supply manifold and the gas ionizer electromagnetic field; a control valve that is in fluid communication with the gas supply manifold and regulates flow of the inert gas from the gas supply manifold to the plasma torch; a process master controller in communication with the sensory kit; a part program that provides a mass flow set value or a volumetric flow set value or both a mass flow set value and a volumetric flow set value to the process master controller; a calculation function running on the process master controller calculating actual volumetric flow; and a) a mass flow control function running on the process master controller; or b) a volumetric flow control function running on the process master controller; and wherein the system further comprises a density control element that controls the temperature and/or pressure of the inert gas delivered to the inlet of the plasma torch. a source of an inert gas; a supply manifold in fluid communication with the source of the inert gas; a plasma torch comprising a gas inlet for receiving the inert gas from an inert gas line connected to the supply manifold, and a gas ionizer electromagnetic field for ionizing the inert gas into plasma; sensory kit comprising a temperature measurement unit, a pressure measurement unit, and a mass flow measurement unit, wherein each unit is in communication with one or more sensory connecters connected to a position of the inert gas line between the supply manifold and the gas ionizer electromagnetic field; a control valve that is in fluid communication with the gas supply manifold and regulates flow of the inert gas from the gas supply manifold to the plasma torch; a process master controller in communication with the sensory kit; a part program that provides a mass flow set value or a volumetric flow set value or both a mass flow set value and a volumetric flow set value to the process master controller; a calculation function running on the process master controller calculating actual volumetric flow; and a) a mass flow control function running on the process master controller; or b) a volumetric flow control function running on the process master controller; and wherein a) a mass flow control function running on the process master controller; or b) a volumetric flow control function running on the process master controller; and wherein the system further comprises a density control element that controls the temperature and/or pressure of the inert gas delivered to the inlet of the plasma torch.