On Thu, 5 Dec 2013 15:46:59 -0500, "Don Phillipson"
wrote:

wrote in message
...
.
I could weigh an empty cylinder, but that could be tomorrow or late next
year

Next time you buy a full cylinder, do you think the store
would allow you to weigh a returned empty as well?

In the US, they are not returned. They are disposible. (Which I always
felt was wrong).