The last time I ran a static test, a bottle of helium from Matheson
Tri-Gas was about $130 which is in the ballpark of the LOX cost. Yes,
that is expensive but insignificant compared to the multiple thousands
of $ spent on test stand, data acquisition equipment, etc. I would have
to be running a lot of tests to consider using N2 as a major cost
savings. I ran my very first set of tests using N2 and I didn't notice
any problem but then again, I was just happy to see hot flamey stuff and
I wasn't looking too closely at performance.
-Bob
