[Clare Gledhill]

As posted on the other thread - for clarification.

The reason that I teach students to label to to one decimal place is to indicate that it is an analysis rather than a fill request. It is common in many dive shops to place tape on cylinders stating the mix required - obviously that would be in round figures. The fact that a label shows the result to one decimal place assists us in recognising that it has been subject to analysis. Given that every diver is trained within GUE to check that not only their own tanks have been analised but that their buddies have also done the same, a proceedure such as this is helpful.

GUE are not alone in teaching this practice. IANTD and TDI instructors do the same in my experience as most would suggest that it can only add a small safety margin to the labeling and identification process.

I would not reject a mix for being less than one per cent out - in fact if it does not affect my dive plans I'd accept it further ouit than this and like Paul says would dive it as intended anyway. To me, labeling is a declaration of analysis both to myself and to others - it bears no relation as to the suitability of the gas or how it is used beyond this.