[chbot] Oxygen / Argon sensor

[Mark Atherton]

I need to store a thermionic emitter in a jar which is free of oxygen, 
and just discovered that argon may an acceptable gas.

Argon is heavier than air, so it may be as simple as filling a small 
vertical container with Ar, and placing the emitter at the bottom.

I do need some simple instrumentation to tell me how full the container 
is, so can either be an argon or an oxygen detector.

Just wondering if anyone has experience using a car oxygen sensor in the 
wild, or if there are any other readily available techniques which 
should be considered (lighted taper would work, but messy).

Thoughts please.

Mark