Oxygen Cocentrator Through Airport Security

Has anyone taken a oxygen concentrator through airport security? If so, were there any issues?

My husband needs oxygen at night so the company who provides his home concentrator has lent us a "travel" one (I use quotes, because it is still a bit large and heavy.) I am concerned about possible issues when going through security. I know each airport is different, but would appreciate knowing anything I should be prepared for.

To answer my own question.

Perhaps it was because I was in a small airport, but I was questioned about the safety of the concentrator at check-in, security and as I was boarding. Luckily atleast one person at each place knew that it was safe for air travel. They did suggest, however, that next time I get a letter from the company indicating that it can be taken on a plane.

We did have a problem because it was about an inch too wide for the overhead compartment and the aircraft did not have a closet. Luckily one of the airline personnel knew where a box was and they packaged it carefully for me and gate checked it. That's one of he advantages of flying a small airline.