Sonic Nozzles are also known as âCritical Flow Venturisâ or âCritical Flow Nozzlesâ. What is a Sonic Nozzle? A âsonic nozzleâ (also known as âCritical Flow Venturiâ or âCritical Flow Nozzleâ) is a flow meter that can be used as a calibration standard for gas flow meters or any flow measurement device. By design, sonic nozzles are a constant volumetric flow meter.
The Abacus: A Brief History. Abacus is a Latin word that has its origins in the Greek words abax or abakon (meaning table or tablet) which in turn, possibly originated from the Semitic word abq, meaning sand. The abacus is one of many types of counting devices which are used to count large numbers.
Actually the Romans applied the word abacus (and also the word calculi, which comes from calculus (stone, pebble) to various objects, all with the common characteristic of having a flat surface: tables used in different kinds of games, sideboards and the calculating device still known as the abacus.ater, loose objects in columns were replaced with beads that could slide along parallel rods. There is an unproved information, that similar to abacus device was used in Babylonia as early as 2400 BC. The word abacus itself is a Latin word, which comes from Greek Î¬Î²Î±ÎºÎ±Ï (board or table).