Peb txoj kev kho cov pH electrode?
Qhov "kev puas tsuaj" ntawm pH composite electrode, qhov tshwm sim yog qhov rhiab heev gradient txo, cov lus teb qeeb, thiab rov ua dua ntawm kev nyeem ntawv tsis zoo. Tej zaum nws yuav tshwm sim los ntawm peb yam hauv qab no. Feem ntau, cov neeg siv khoom tuaj yeem siv cov txheej txheem tsim nyog los kho nws.
1. Lub qhov muag hluav taws xob thiab cov kua dej sib txuas yog cov pa phem, thiab cov av tuaj yeem ua tib zoo tshem tawm nrog txhuam zoo, paj rwb lossis tshuaj txhuam hniav. Kev tiv thaiv npog ntawm qee lub plhaub yas electrode taub hau tuaj yeem raug tshem tawm, uas yooj yim rau kev ntxuav. Yog tias muaj kuab paug hnyav, nws tuaj yeem ntxuav nrog xab npum raws li txoj hauv kev hauv Tshooj 8.
2. Cov tshuaj siv sab nraud yog qias neeg. Qee cov qauv electrode tuaj yeem muab ntxiv rau cov tshuaj. Nyob rau lub sijhawm no, cov tshuaj siv sab nraud ntawm cov electrode tuaj yeem tso tawm nrog lub koob txhaj tshuaj, thiab cov tshuaj 3.3mol / L tshiab tau npaj, thiab tom qab ntawd ntxiv. Nco ntsoov tias nws yuav tsum tau rub tawm thaum nws ntxiv rau thawj zaug thiab zaum ob, txhawm rau ntxuav cov kab noj hniav sab hauv ntawm electrode.
3 Kev laus ntawm iav rhiab zaj duab xis: Soak lub qhov muag hluav taws xob hauv 0.1mol/L dilute hydrochloric acid (9mL hydrochloric acid diluted rau 100mL nrog dej ntshiab) rau 24 teev, ntxuav nws nrog dej ntshiab, thiab tom qab ntawd tsau rau hauv cov electrode soaking tov rau 24 teev. Yog hais tias tus passivation loj heev, koj tuaj yeem tsau qhov qis kawg ntawm cov electrode hauv 45 hydrofluoric acid tov rau 3-5 vib nas this (kev daws teeb meem: dilute 4 mL hydrofluoric acid rau 100 mL nrog dej ntshiab), ntxuav nws nrog dej ntshiab. , thiab tom qab ntawd Soak cov electrode hauv cov kua dej so rau 24 teev los kho nws cov kev ua tau zoo.
Qhov kub npaum li cas cuam tshuam rau kev ntsuas pH?
Rau pH electrodes, qhov kub thiab txias cuam tshuam rau txhua pH los ntawm {{0}}}003pH / degree . Piv txwv li, ib tug 0.2- qib pH meter yog calibrated nyob rau hauv ib tug pH buffer tov ntawm 30 degree, thiab ces cov tshuaj ntawm 60 degree yog kuaj (xav tias pH ntau ntawm cov tshuaj yog nruab nrab ntawm pH 6-8) Qhov txawv ntawm pH 7.00 thiab pH 7.00 yog ib pH unit), ces qhov siab tshaj plaws yuam kev cuam tshuam los ntawm kub yog 30 × 0.003=0.09pH . Yog tias nws yog 3 pH units (hauv pH 4-10 ntau), qhov yuam kev siab tshaj plaws yog 0.27pH, uas nws tuaj yeem pom tias qhov kub thiab txias muaj qhov cuam tshuam zoo rau pH. Tau kawg, peb kuj tuaj yeem txiav txim siab los ntawm nws. Txhawm rau txo qhov ua yuam kev ntawm qhov ntsuas kub rau pH ntsuas, peb yuav tsum ua tib zoo saib peb cov ntsiab lus hauv qab no:
1. Sim xaiv cov tshuaj tsis nyob ze rau tus nqi pH ntawm cov tshuaj uas yuav tsum tau ntsuas los ntsuas pH meter.
2 Sim ua kom qhov kub thiab txias ntawm cov tshuaj calibration zoo tib yam lossis ze rau qhov ntsuas kub ntawm cov tshuaj ntsuas.
3 A pH meter nrog kub them nyiaj yuav tsum tau xaiv.
pH meters nrog qhov tseeb siab dua {{0}}.1 pH muaj qhov kub thiab txias hloov pauv, thaum pH ntsuas nrog qib ntawm 0.2 tsis muaj qhov kub thiab txias. Qee qhov 0.2- qib pH ntsuas kuj tseem hais tias muaj 0 1- qib raug. Qhov tseeb, qhov no yog ua tsis tau. Qee tus neeg tsis meej pem ob lub ntsiab lus ntawm kev daws teeb meem {{10}}.1pH thiab precision 0.1pH. Txawm hais tias nyob rau hauv ib chav tsev pH, pH yuam kev ntawm qhov deb ntawm 60 degree yog 0.003 × 60=0.18pH. Yog li, qhov tseeb tshaj plaws ntawm pH meter yam tsis muaj qhov kub thiab txias tsuas yog 0.2 pH.
