device which consists of a convergent inlet connected to a cylindrical part called the “throat”, which is itself connected to an expanding section called the “divergent” which is conical, mõõtevahendi osis, mis koosneb konvergentsest sisselaskeavast ja on ühendatud silindrilise osaga, mida nimetatakse "kurguks" ühendatuna laieneva/lahkneva koonilise sektsiooniga