>Your solution is unlikely to be unique. <<br> _________________________
My replies were in that sense, but deleted them on the lack of knowledge base from the originator. It must be made clear what the project is solving for. Either: Q, DP, D having fixed the other two. The other point was about "most accurate", most accurate vs what ? As such the worksheet is for pipe line sizing but not for metering. For flow metering, there must be a flow primary element that we either size [orifice plate] or other fixed geometry primary devices that of which the DP is calculated for calibrating the XTR. There are lot of variables but not a single definition and whereas natural gas varies in the $ part purchased or sold, my conclusion was that I had no interest in contributing more especially after reposting a work sheet in exclusive version.
jmG