Dab tsi yog "nti": nti (") yog ib qho kev sib raug zoo tshwj xeeb rau cov kav dej Asmeskas, cov roj ntsha, tees, xws li lwm yam, xws li lwm yam yog 10".
Nties (nti, lus luv li nyob rau hauv.) txhais tau tias tus ntiv tes xoo hauv Dutch, thiab ib nti yog qhov ntev ntawm tus ntiv tes xoo. Ntawm chav kawm, qhov ntev ntawm tus tib neeg tus ntiv tes kuj sib txawv. Nyob rau hauv lub xyoo pua 14, Vaj Ntxwv Edward II tshaj tawm cov qauv "qauv raug cai".
Nws tau hais tias qhov ntev ntawm peb cov nplej loj tshaj plaws xaiv los ntawm nruab nrab ntawm pob ntseg barley thiab npaj uake yog ib nti.
Feem ntau 1 "= 2.54cm = 25.4 hli
Dab tsi yog DN: DN yog ib feem ntawm cov lus qhia hauv Suav thiab European systems. Nws tseem yog kev tshwj xeeb rau kev txheeb xyuas cov kav dej, li qub, flanges, cov yeeb nkab fittings thiab twj, xws li DN250.
DN hais txog cov kabinal ntawm cov yeeb nkab (tseem hu ua txoj kab uas hla), nws yog qhov nruab nrab ntawm lub taub thiab sab hauv lub taub.
Dab tsi yog φ: φ yog ib qho dav dav, uas yog hais txog txoj kab uas hla sab nraud ntawm kav dej, laujbows, hlau thiab lwm yam ntaub ntawv. Nws kuj tseem tuaj yeem hais kom lub cheeb. Piv txwv li, φ609.6mm yog hais txog cov cheeb tsam sab nraud ntawm 609.6mm.
Tam sim no uas peb tau xam tawm peb cov nyob rau peb cov neeg no yog dab tsi, qhov kev sib txuas ntawm lawv yog dab tsi?
Ua ntej tshaj plaws, "lub ntsiab lus ntawm" yog yuav luag zoo ib yam li ntawm DN, yog txhais tau tias yog qhov loj me ntawm qhov kev qhia tshwj xeeb, thiab φ yog los ua ke ob.
Piv txwv li: Yog tias cov yeeb nkab steel yog DN600, thiab tib cov yeeb nkab steel yog khij nrog nti, nws ua 24 ". Puas muaj kev sib txuas ntawm ob qho?
Cov lus teb yog yog! Cov nti dav dav yog qhov ncaj qha sib npaug ntawm cov lej los ntawm 25, uas yog sib npaug rau DN, xws li 1 "* 25 = 50 4" * 25 = DN100 thiab lwm yam.
Tau kawg, tseem muaj ntau qhov, xws li 3 "* 25 = 75/2" 3-1 / 2 "3-1 / 2" 3-1 / 2 "3-1 / 2")
1/2 "= DN15 3/4" = Dn20 1-1 / 4 "= Dn32 1-1 / 2" = DN60 2-1 / 2 "= DN90
Lub sijhawm Post: Mar-10-2022
