Air and nitrox fills for divers and for the liveaboards that stop here. The compressor is serviced quarterly and the air quality test certificate is on the wall by the counter with the date on it, because a fill station that cannot show you one is a fill station to walk away from.
Nitrox is analysed by you in front of us and signed for by you. That is how it is supposed to be done and we do not skip it for regulars.
Tanks are visually inspected annually and pressure tested on schedule. The stamps are on the necks and you are welcome to look.