had a strange response from my local dive shop, they said, something along the lines of "it is a hydrogen (something that was garbelled) and as such we can not test it".
is this something new or have i just picked a naff dive shop, it is a evil tank. and has been out of date for about 2 years so was dubious if they would test it, but the excuse seems a bit strange, the dead date was 01/2022