' that Ni is more stable for a change in temp. is not true. Even the Ni companies don't say that. This is the first line of the paragraph that I got from their web site.
'Fundamentally, air, oxygen and nitrogen will all behave exactly the same, in terms of just how much pressure will change for each 10 degrees of temperature change
If you can remember anything about your old chemistry class
this is one of the 'Gas Laws' which basically says all gases or mixture of gases expand/contract the same amount. (I had to look it up!!).