I-kilogram yereferensi yenziwa ngendlela yesilinda, ibaluleke kakhulu kwaye ngoku ngaphezulu kwenkulungwane igcinwe kumazantsi eParis. Kukwi-valuo kwiqokobhe elikhethekileyo leglasi.
Ngaphakathi ku-Novemba ka-2019, kwinkomfa ye-26 ye-Ofisi yeHlabathi yeLizwe kunye nesikali, iingcali ziya kuthatha isigqibo sokutshintsha i-Gry K kwireferensi enokuthenjwa.
Umgangatho unemilo ye-cylindricaal ene-diameter esekwe kunye nobude obuyi-39 mm, iipesenti ezingama-90 zineplatinam, kwaye nge-10% ukusuka kwi-Irididium. Kuye ukuba zonke ii-viscos zithelekiswa neplanethi. Uneekopi abekwe kwihlabathi jikelele kumaziko oluntu kwi-metrology. Ngoku iyunithi enkulu yenye kuphela kwinkqubo yemilinganiselo yamazwe, ethathwa kwisifundo esenziwe ngumntu. Ezinye iiyunithi zale nkqubo zinokufumaneka kusetyenziswa imithetho yefiziksi. Kodwa ayisiyonto ixesha elide.
Unobangela wokuokuphulukana ne-atom yekhilogram, ngenxa yokuba abantu abaninzi. Ngoku ukuba ilingana nezinye iikopi zeekhilogrem (oku kwenza iminyaka engama-40), isiphumo siya kwahluka. Oku kunokukhokelela kwiingxaki ezinkulu kumashishini, apho ukuchaneka komlinganiso kubaluleke kakhulu.
Kukho indlela ebonakaliswayo ngokuchaneka okukhulu. Ngo-1975, uGqr. Bryan Kribble ovela eBritani, ke obizwa ngokuba ngu "Vetta-Scales" ngo-1975. Kuxhomekeke kwinto yokuba amandla e-elektromagnetic amandla alinganiswa, enokulinganiswa ngokuchaneka okuphakathi. Oku kufuna izixhobo ezinzima kakhulu kwaye zibiza kakhulu. Kwizixhobo zelebhu, utyalomali olukhulu luyafuneka, kodwa oku kuqaliswa kuya kuvumela ukufumana isiseko se-setrological.
Inqaku ngesihloko: Ukukhutshwa kwefanitshala - inqanaba elitsha lophuhliso vipp