Kev tawg- cov qhov rooj pov thawj, yog cov cuab yeej tiv thaiv kev nyab xeeb tseem ceeb, ua lub luag haujlwm tseem ceeb hauv kev lag luam, kev lag luam, thiab pej xeem. Lawv qhov kev faib tawm ncaj qha cuam tshuam rau lawv lub peev xwm tiv thaiv thiab siv tau.
Kev faib tawm ntawm kev tawg- cov qhov rooj pov thawj feem ntau yog ua raws li kev txiav txim siab ntawm ntau yam, suav nrog qhov loj ntawm qhov tawg siab uas lawv tuaj yeem tiv taus, lawv qhov cuam tshuam tsis kam, thiab lawv qhov kev sib khi ua haujlwm. Tam sim no, tawg-cov ntaub ntawv pov thawj qhov rooj ntawm kev ua lag luam feem ntau muab faib ua ob peb chav kawm, suav nrog tab sis tsis txwv rau Chav Kawm A, Chav B, thiab Chav C. Cov kev faib tawm no feem ntau ua raws li cov txheej txheem thoob ntiaj teb lossis cov qauv hauv tsev, xws li EU tus qauv EN lossis Tuam Tshoj tus qauv GB.
Tshwj xeeb tshaj yog, Chav Kawm A tawg- cov qhov rooj pov thawj feem ntau yog tsim los tiv thaiv qhov cuam tshuam qis dua thiab tsim nyog rau cov chaw uas muaj kev nyab xeeb tsawg. Cov qhov rooj no kuj yooj yim hauv kev xaiv cov khoom siv thiab cov qauv tsim, tab sis tseem ua tau raws li kev tawg yooj yim - pov thawj xav tau. Lawv kuj pheej yig, nrog rau cov nqi lag luam feem ntau yog li ntawm ntau txhiab mus rau kaum tawm txhiab yuan, nyob ntawm seb qhov loj me, cov ntaub ntawv, thiab kev hloov kho.
Class B tawg- cov qhov rooj pov thawj, ntawm qhov tod tes, muaj kev tawg ntau dua- pov thawj muaj peev xwm thiab tuaj yeem tiv taus nruab nrab - siv lub tshuab tawg. Cov chav kawm B tawg no- cov qhov rooj pov thawj yog ua los ntawm cov ntaub ntawv muaj zog dua, xws li siab - lub zog steel lossis cov alloys tshwj xeeb, thiab lawv cov qauv tsim yog qhov nyuaj dua los xyuas kom muaj kev cuam tshuam zoo ntawm kev cuam tshuam lub zog thaum tawg, tiv thaiv cov qauv sab hauv thiab cov neeg ua haujlwm. Class B tawg-cov ntaub ntawv pov thawj qhov rooj feem ntau kim, txij li kaum tawm txhiab mus rau ntau pua txhiab yuan, nyob ntawm qhov tshwj xeeb thiab teeb tsa.
Class C tawg-cov ntaub ntawv pov thawj qhov rooj yog siab- cov khoom kawg nrog tawg siab heev- pov thawj muaj peev xwm thiab cuam tshuam. Cov qhov rooj no feem ntau yog siv rau hauv qhov chaw uas muaj kev nyab xeeb siab heev, xws li petrochemical thiab nuclear fais fab nroj tsuag. Class C tawg-cov ntaub ntawv pov thawj qhov rooj ua tau zoo heev ntawm kev xaiv cov khoom, kev tsim qauv, thiab cov txheej txheem tsim khoom, muaj peev xwm tiv taus qhov cuam tshuam tawg nyob rau hauv cov xwm txheej hnyav, ua kom muaj kev nyab xeeb ntawm cov neeg ua haujlwm thiab cov khoom siv. Vim lawv qhov siab -qhov kawg qhov chaw, Class C tawg- cov qhov rooj pov thawj kuj tseem kim, nrog rau cov nqi lag luam muaj peev xwm tshaj li pua pua txhiab yuan lossis ntau dua.
Ntxiv rau cov kev faib tawm saum toj no, tawg- cov qhov rooj pov thawj kuj tuaj yeem hloov kho raws li cov xwm txheej tshwj xeeb thiab cov kev xav tau, xws li kev ntxiv hluav taws kub, tiv thaiv- tub sab, thiab lub suab tsis muaj zog kom tau raws li tus neeg xav tau kev pab ntawm cov neeg siv khoom sib txawv. Thaum xaiv tawg- qhov rooj pov thawj, ntxiv rau kev txiav txim siab lawv qhov kev ntaus nqi thiab kev ua tau zoo, kuj tseem yuav tsum tau them nyiaj rau lawv cov kev teeb tsa, kev saib xyuas, thiab tom qab- kev muag khoom los xyuas kom meej tias qhov tawg- cov qhov rooj pov thawj tuaj yeem ua lub luag haujlwm ruaj khov hauv lub sijhawm ntev.
