What do the simplest PAC units use for cutting materials?

The simplest Plasma Arc Cutting (PAC) units use clean compressed air for cutting materials because it serves as an effective and readily available medium that assists in creating the plasma arc. Compressed air is a low-cost option that provides adequate ionization and stability for the plasma process while also being able to effectively cool and control the cutting operation.

Using clean compressed air allows for a good cutting capability on various materials, particularly when working with ferrous and non-ferrous metals, without requiring special gases that might be more expensive or difficult to procure. Additionally, it helps to ensure that the cutting process remains environmentally friendly by avoiding harmful emissions associated with other gas types.

In contrast, other gases like carbon dioxide or helium aren't typically found in the simplest PAC units due to factors such as cost or limitations in cutting effectiveness. Fuel gas mixtures may also not be as viable in basic PAC applications since they can introduce complications in the plasma generation process. Thus, the choice of clean compressed air highlights the practicality and efficiency required in the operation of basic PAC units.