Pattern Approval Certificate(A manufacturer has to supply instruments to a national laboratory which tests one of them and if it meets its claims issue a formal Pattern Approval certificate. wiki)
Pattern Approval Certificate(term used only in the context of measuring instruments; A manufacturer has to supply instruments to a national laboratory which tests one of them and if it meets its claims issue a formal Pattern Approval certificate. wiki Alexander Demidov)
displacer(не путать с поплавковым = float level gauge; принцип действия основан на законе Архимеда: зависимости выталкивающей силы, действующей на буек, от уровня жидкости ... Полное описание и отличие от поплавкового см. на eti.suMixer)