Guys* hope you can help me out with this.

There's a table on AGA3 that specifies lots of lengths based on the ß of the configuration (dr/DR):



Question is: whenever I find myself in a situation where ß is not a round number like 0.2* 0.3* 0.4* etc.* suppose 0.45* to which line of the table should I refer as guidance? The ß=0.3 or the ß=0.4 line? Is there any "official" reference about the right choice to make?

Sorry if this is not the best place to post this but I couldn't find anything specific related to natural gas measurement around.

Kind Regards*
VB