Ib qho taw tes calibration ntawm pH meters yog dab tsi?
Txhua lub pH ntsuas yuav tsum tau ntsuas los ntawm pH Standard tov ua ntej ntsuas pH tus nqi ntawm tus qauv. Rau cov qauv nrog kev ntsuas qhov tseeb ntawm {{0}}.1 thiab qis dua pH, ib txoj kev ntsuas qhov taw qhia tuaj yeem siv los kho qhov ntsuas. Feem ntau, pH =6 86 los yog pH =7 00 txheem buffer tov yog siv. Qee cov cuab yeej lawv tus kheej tsuas yog muaj pH ntawm 0.2 lossis 0.1, yog li lawv tsuas muaj qhov hloov kho qhov chaw. Cov kauj ruam ua haujlwm tshwj xeeb yog raws li hauv qab no:
(1) Ntsuas qhov ntsuas kub ntawm cov txheej txheem kev daws teeb meem, tshawb xyuas lub rooj los txiav txim siab pH tus nqi ntawm qhov kub thiab txias, thiab kho qhov kub thiab txias qhov kub ntawm qhov kub no;
(2) Yaug cov electrode nrog dej ntshiab thiab co kom qhuav;
(3) Muab cov electrode tso rau hauv cov tshuaj tsis haum thiab co nws, ces muab tso rau hauv. Tom qab kev nyeem ntawv ruaj khov, kho qhov chaw qhov rooj kom lub ntsuas ntsuas pH tus nqi ntawm cov txheej txheem daws teeb meem;
(4) Tshem tawm cov electrode thiab yaug nws thiab co kom qhuav;
(5) Ntsuas qhov ntsuas kub ntawm tus qauv thiab kho qhov ntsuas pH ntsuas kub qhov nyiaj qhov kub rau qhov ntsuas kub no;
(6) Muab cov electrode tso rau hauv cov qauv kev daws teeb meem, co nws, thiab tom qab ntawd sawv ntsug kom pom kev nyeem ntawv ruaj khov.
Dab tsi yog qhov ob-point calibration ntawm pH meters?
Rau precision pH meters, ntxiv rau "kev tso chaw" thiab "kub them nyiaj" kev hloov kho, kuj tseem muaj kev hloov kho electrode "slope", uas yuav tsum tau calibration nrog ob txoj kev daws teeb meem tsis zoo. Feem ntau, ua ntej ua "txoj hauj lwm" calibration nrog pH =6 86 los yog pH =7 00, thiab ces xaiv pH =4 00 (acidic) los yog pH=9.18 los yog pH=10.01 (alkaline) buffer tov rau "txoj kab nqes kho" raws li acidity thiab alkalinity ntawm cov tshuaj ntsuam xyuas. Cov kauj ruam ua haujlwm tshwj xeeb yog raws li hauv qab no:
(1) Ntxuav thiab qhuav cov electrode, muab tso rau hauv cov txheej txheem tov nrog pH=6.86 los yog pH=7.00, thiab muab qhov kub thiab txias qhov kub ntawm qhov kev daws kub. Tom qab tus nqi qhia tau ruaj khov, kho qhov chaw qhov rooj kom qhov ntsuas qhov ntsuas yog pH tus nqi ntawm Standard tov.
(2) Tshem tawm cov electrode, ntxuav thiab qhuav nws, thiab muab tso rau hauv qhov kev daws teeb meem thib ob. Tom qab tus nqi qhia tau ruaj khov, kho txoj kab nqes pob qhov ntsuas ntawm qhov ntsuas kom tus nqi ntawm qhov ntsuas yog pH tus nqi ntawm qhov thib ob Standard tov.
(3) Ntxuav thiab qhuav cov electrode, thiab ces muab tso rau hauv tus txheej txheem tov pH6.86 los yog pH7.00. Yog tias qhov yuam kev dhau 0.02pH, rov ua cov kauj ruam (1) thiab (2). Kom txog rau thaum tus nqi PH raug tso tawm tuaj yeem pom nyob rau hauv ob qho tib si Standard tov yam tsis tau kho lub pob qhov rooj.
(4) Tshem tawm cov electrode, ntxuav nws thiab co kom qhuav. Kho qhov pH kub them pob qhov rooj rau cov qauv ntsuas kub, muab cov electrode rau hauv cov qauv tov, co nws, thiab tom qab ntawd sawv ntsug. Tom qab cov zaub ruaj khov, kev nyeem ntawv yuav ruaj khov
