A Yard Stick and a Scale, of course !
I'm sorry I just couldn't resist .
(I am puzzeled how someone with so much (stated) education in a field has such a significant lack of knowledge in that field.)
If sense were so common everyone would have it !
All opinions expressed are my own. Any advice provided is based on personal experience, generally accepted fact or publicly available information. As such, it is worth exactly what you paid for it, not a penny more not a penny less !!