Cov kauj ruam thiab cov txheej txheem rau calibrating pH meters
1. PH meter siv hauv chav kuaj|Acidity meter calibration:
Thaum calibrating feem ntau siv pH ntsuas ntsuas, txoj kab nqes ntawm qhov ntsuas yuav tsum tau hloov mus rau qhov siab tshaj plaws thiab cov roj hmab ntsaws rau sab sauv ntawm cov electrode yuav tsum raug tshem tawm kom nthuav tawm lub qhov me me. Txwv tsis pub, thaum lub sij hawm calibration, lub siab tsis zoo yuav raug tsim, ua rau cov kev daws teeb meem tsis tuaj yeem pauv ions ib txwm thiab ua rau cov ntaub ntawv ntsuas tsis raug.
Tshem cov electrode los ntawm lub beaker uas muaj cov dej distilled thiab siv cov ntawv lim kom nqus cov dej distilled seem ntawm cov electrode. Tom qab ntawd muab cov electrode tso rau hauv lub beaker nrog kev sib xyaw phosphoric acid phiab, tos ntev dua 15 min, thiab tom qab ntawd kho cov pob qhov rooj ntawm lub ntsuas ntsuas kom ntsuas ntsuas 6.86 pH. Nov yog thawj zaug los teeb tsa qhov taw qhia siv rau qhov ntsuas. Tom qab teeb tsa qhov taw qhia, tshem cov electrode ntawm lub beaker uas muaj cov tshuaj phosphoric acid tov, ntxuav cov electrode nrog dej distilled, thiab muab tso rau hauv lub beaker uas muaj dej distilled. Tos li 3 feeb kom yaj cov seem ntawm cov tshuaj phosphoric acid tov.
2. Tom qab ntawd, tshem cov electrode ntawm lub beaker uas muaj cov dej distilled thiab siv cov ntawv lim kom nqus cov dej distilled seem ntawm cov electrode. Tom qab ntawd muab cov electrode tso rau hauv cov tshuaj uas muaj Potassium hydrogen phthalate lossis borax, tos ntev dua 15 min, thiab Saib cov ntsuas ntsuas 4.00 lossis 9.18 pH. Yog tias tsis yog, kho lub pob qhov rooj ntawm qhov ntsuas kom pom 4.00 lossis 9.18 pH, uas yog ib qho kev kho ob-taw tes. Yog xav tau kev kho peb lub ntsiab lus, tsuas yog rov ua cov kauj ruam saum toj no rau lwm qhov kev daws teeb meem. Qhov no yog txoj kev calibration rau acidity meters.
3. Tom qab calibration, ntsaws cov roj hmab ntsaws rov qab rau hauv. Yog tias tsis siv ib ntus, nco ntsoov nruab cov tshuaj saturated rau hauv lub tes tsho tiv thaiv ntawm electrode kom cov electrode moist. Qhov no tuaj yeem txuas ntxiv lub neej ntawm cov electrode thiab txo cov peev xwm asymmetric ntawm cov electrode. Electrodes muaj lub neej ntev thiab suav tias tsis yooj yim. Yog li ntawd, ntau lub chaw soj nstuam yuav tsum nquag hloov cov electrodes, thiab tsis txhob xav tias cov electrodes tsis puas thaum siv.
4. Ua ntej siv cov khoom siv hluav taws xob sib xyaw, ua ntej kuaj lub iav qhov muag kom pom kev tawg thiab tawg. Yog tias tsis yog, siv cov tshuaj pH tsis haum rau ob lub ntsiab lus calibration. Thaum qhov chaw thiab txoj kab nqes pob tuaj yeem hloov kho rau tus nqi pH, nws feem ntau suav hais tias siv tau. Txwv tsis pub, kev kho electrode ua kom muaj peev xwm ua tau raws li tus neeg siv phau ntawv. Txoj kev ua kom yog raus rau hauv 4 feem pua hydrogen fluoride tov rau li 3-5 vib nas this, ces tshem tawm thiab yaug kom huv si nrog dej distilled; Tom qab ntawd tsau rau hauv ib qho 0.1 mol/L phiab acid tov rau ob peb teev, yaug kom huv si nrog dej distilled, thiab ces calibrate. Rau qhov tsis raug kaw cov electrode, yog tias cov tshuaj sab hauv tsawg dua 1/3, cov tshuaj siv sab nraud, uas yog 3mol / L Potassium fluoride tov, yuav tsum tau ntxiv. Yog tias cov tshuaj Potassium fluoride tshaj qhov chaw ntawm lub qhov me me, co tawm cov tshuaj ntxiv Potassium fluoride thiab xyuas seb puas muaj npuas hauv cov tshuaj. Yog tias muaj npuas, maj mam flick lub electrode kom tshem tawm cov npuas kom tsis txhob muaj cov ntaub ntawv ntsuas tsis raug.
5. Calibration method rau cwj mem pH meter:
Raus lub xeem cwj mem electrode nyob rau hauv ib tug sib tov phosphate standard tsis nrog ib tug pH nqi ntawm 6.86 (ntawm 25 degree) thiab maj mam co nws; Siv lub taub hau me me los kho thiab ntsuas lub Potentiometer kom txog rau thaum cov txiaj ntsig pom tau zoo ib yam nrog tus nqi pH ntawm cov txheej txheem tsis haum ntawm qhov ntsuas kub; Ntxig cov electrode rau hauv cov txheej txheem tsis daws teeb meem ntawm potassium hydrogen phosphobenzoate ntawm pH 4.01 lossis borax ntawm pH 9.18; Tus nqi tso tawm yuav tsum nyob rau hauv qhov tso cai yuam kev piv rau pH tus nqi ntawm cov tshuaj tsis haum.
