A study of phase equilibria of nitrogen for constructing a medium value pressure scale

We see that with increasing frequency of emitted signal f the absence of superposition of a doubly reflected signal upon basic signal (7) is attained more easily and measurement errors 6' and 6" are reduced. Usually, in ultrasound flow meters, piezoelement assemblies with ceramics protected by fluoroplastic from the flow have Az/A c = 0.08-0.1, while wholemetal assemblies have AI/A c = 0.2-0.25.