1) Tshawb xyuas qhov rwb thaiv tsev ntawm lub davhlau ya nyob twg ncej thiab lub ntiaj teb. Tus nqi kuj yuav tsum siab tshaj 100 txhiab OHms thiab ntsuas nrog ib tug multimeter. Yog tias nws tsawg dua tus nqi no, xyuas seb lub davhlau ya nyob twg ncej yog grounded nrog coated steel yeeb nkab.
2) Cov pawg xeem yuav tsum tau pleev xim rau thiab suav tsis tu ncua txhua xyoo.
3) Tiv thaiv kev puas tsuaj thiab poob ntawm pawg sim, thiab tshaj tawm thiab qhia cov neeg nyob hauv nroog thiab cov neeg nyob deb nroog thiab cov menyuam yaus raws txoj kev los tiv thaiv lub tebchaws.
