"Don W" wrote in message
. ..

Now that is an interesting way of doing it. Just check the pressure on
preflight, and you'll know there aren't any cracks if it's still holding
pressure.

Well . . . you will know that the gauge pointer hasn't moved. For fire
extinguisher classes, I had a demo extinguisher which was cut open so's you
could see the interior. The gauge still read in the green.

Rich S.