Carbonless luam ntawv thiab daim ntawv xiav luam ntawv hauv cov ntawv carbon yog ob qho tib si siv los luam cov ntawv sau. Thaum siv, nws yog ib qho tsim nyog yuav tsum tau superimpose ob qho tib si kom ua tiav cov txiaj ntsig ntawm kev luam. Nws yog inevitable tias kev luam qhov yuam kev yuav tshwm sim thaum siv. Thaum twg muaj qhov yuam kev, koj puas ncaj qha tsis muaj nws lossis nrhiav txoj hauv kev los tshem tawm cov ntawv sau? Cov lus sau rau ntawm daim ntawv tsis muaj cov ntawv luam puas tuaj yeem raug tshem tawm nrog lub lwv?
Yuav kom nkag siab qhov no, peb yuav tsum tau saib lub hauv paus ntsiab lus ntawm carbonless luam ntawv ua ntej. Feem ntau hais lus, pem hauv ntej ntawm cov ntawv luam tsis muaj carbon yog coated nrog cov xim acidic tsim, thiab sab nraub qaum muaj leuco dye. Thaum cov ntawv luam tawm tsis muaj cov pa roj carbon monoxide yog folded, nws yuav raug cuam tshuam los ntawm qhov kev txiav txim ntawm sab nraud quab yuam ua rau leuco luam ntawv dye hloov xim thaum nws ntsib cov kua qaub los ua cov duab, yog li cov ntawv sau tsis raug tuaj yeem raug tshem tawm ncaj qha nrog ib qho yooj yim lwv.
Yog li kuv yuav ua li cas yog tias kuv sau ntawv sau tsis raug rau ntawm daim ntawv tsis muaj carbon? Nws raug pom zoo tias koj tuaj yeem siv cov paj rwb swab lossis lwm yam me me uas tuaj yeem pleev xim, txhuam tus nqi tsim nyog ntawm cov dej hauv chav dej thiab maj mam smear rau ntawm kev sau ntawv kom ua tiav lub hom phiaj ntawm kev tshem tawm cov ntawv sau xiav. Tau kawg, txoj kev no tsuas yog tsim nyog rau qhov me me ntawm kev sau ntawv yuam kev. Yog tias muaj qhov yuam kev loj loj, nws raug nquahu kom koj ncaj qha rhuav tshem lossis siv lwm txoj hauv kev los tshem tawm cov ntawv sau.