I-vacuum ifuneka kwiintlobo ezithile zokwenza imveliso zoshishino. Iimpompo ze-vacuum zisetyenziselwa ukumpompa umoya ziwukhuphela ngaphandle kwi-vacuum. apha ekuhlaleni i-100% akunto enokufane yenzeke, kodwa inkoliso yeempompo ze-vacuum ziyakwazi ukwenza i-vacuum eyi-99.9999%. le ke ibizwa ngokuba y""ivacuum eyomeleleyo"". Inkoliso yeenjongo zoshishino azifuni vacuum iqinileyo; eyi-0.001% ilunge ngokwaneleyo.