Nitrogen Partial Pressure Control

The nitrogen partial pressure is not really what you need to watch out for when welding – it only affects the gas atmosphere if you work with nitrogen fractions in the shielding gas. The edge zone and its properties depend much more on heat input, cooling, and the composition of base and filler material. If you get too much nitrogen into the weld pool, it can cause porosity or brittleness, but that's more of a problem with wrong gas selection or leaking hoses. Just make sure your shielding gas is right and you weld cleanly, then you don't need to worry about the partial pressure.