Qhov kev nrawm nrawm ntawm kev siv hniav qis dua yog feem ntau ntawm 500 rpm thiab 200, {} rpm. Tsawg cov tes ceev feem ntau xa mus rau cov tes ua ke nrog kev kub ntxhov ntawm 20, {} rpm txog 200, {} rpm. Nrog qhov nrawm nroos, nce nce zuj zus thiab nrawm dua li 500 rpm thiab siab li 200, {rpm.
Ib qho ntxiv, kev kho hniav qis npaum li cas muaj ntau lub luag haujlwm thiab haum rau kev kho hniav kev kho hniav thiab kev xav tau kev kho mob. Piv txwv li, lawv tuaj yeem siv rau ntau yam kev ua haujlwm xws li hniav kho kom zoo, txhuam hniav, thiab tuaj yeem hloov kho raws li cov kev xav tau ntawm cov kws kho mob kom ua tiav cov haujlwm zoo. Cov khoom siv ceev ceev kuj muaj cov yam ntxwv ntawm cov suab nrov tsawg thiab qis dua kev co, txo qhov tsis xis nyob ntawm cov kws kho mob thiab cov neeg mob.