It might be more convenient to purchase pre-blended mixes for many applications. For example 90% argon 10% isobutane. In welding this would be "impure" but for

It might be more convenient to purchase pre-blended mixes for many applications. For example 90% argon 10% isobutane. In welding this would be "impure" but for ionization counting it's exactly what you want.