Why Nitrogen as sheath gas ?

[shadowcand]

Hello

I would like to ask you a question.

Why is the Nitrogen used as sheath gas? Why not Argon or Helium ?

Thank you.

[CE Instruments]

Helium is most unsuitable. Far too light to act as a sheath and expensive compared to Nitrogen. Argon might work but again with the volumes used Nitrogen must be the best choice ?

[shadowcand]

Helium is most unsuitable. Far too light to act as a sheath and expensive compared to Nitrogen. Argon might work but again with the volumes used Nitrogen must be the best choice ?

Thank you for information.

[mckrause]

Argon actually works better than nitrogen. Found this out by running out of nitrogen one day, had to steal the argon tank from the ICP. Nitrogen is cheaper by far, and works adequately.