Thermal ntawv yog ib daim ntawv tshwj xeeb tshwj xeeb, nws cov tsos yog zoo ib yam li cov ntawv dawb zoo tib yam. Txheej txheej saum npoo ntawm cov ntawv thermal yog du. Nws yog ua los ntawm daim ntawv dog dig raws li daim ntawv puag. Ib txheej ntawm thermosensitive chromogenic txheej yog coated nyob rau saum npoo ntawm daim ntawv dog dig. Lub chromogenic txheej yog ua los ntawm cov nplaum, tus tsim tawm, cov khoom lag luam qev (lossis cov tshuaj lom neeg tsis tau sib cais, thiab cov tshuaj lom neeg muaj nyob hauv "latent" xeev. Thaum cov ntawv thermal tau ntsib ib lub cua sov {{5 5}} generating luam tawm lub taub hau, tsim xim thiab hloov xim thiab cov ntawv nyeem.
Thaum daim ntawv thermal yog muab tso rau hauv ib puag ncig ntawm 70 degree, cov txheej thermal pib hloov xim. Qhov laj thawj rau nws discoloration tau yuav tsum tau sib tham los ntawm nws muaj pes tsawg leeg. Muaj ob lub ntsiab cua sov -} Cov khoom siv uas rhiab heev: ib qho yog qhov zas xim qis: qev zas; Lwm tus yog tus tsim tawm. Hom thermal no tseem yog hu ua ob - sib xyaw ua tshuaj lom cov ntaub ntawv sau ua hluav taws xob.
Feem ntau siv los ua leuco dyes yog feem ntau yog: Crystal violet lactone (CVL) Feem ntau siv los ua cov xim reagents tsuas yog: Para {{{}} Hydrox acid, 2,4-dihydrenzoic acid los yog cov kua qaub.
Tom qab cov ntawv thermal yog rhuab, cov leuco zas xim nrog cov teeb meem los tsim cov teeb liab, yog li thaum cov duab luam ntawv ncaj qha, cov duab thiab cov ntawv nyeem yuav raug tso tawm kom pom. Vim tias muaj ntau yam leuco dyes, cov xim ntawm sau ntawv sib txawv, xws li xiav, fuchsia, dub, thiab lwm yam.
