Kev siv cov ph meter hauv kev ntsuas av ph acidity thiab alkalinity
Cov ntsiab lus ntawm ph meter ntsuas txoj kev
Lub pH ntawm cov av yog txiav txim los ntawm txoj kev potentiometric. Cov pH iav electrode thiab cov calomel electrode yog muab tso rau hauv av ncua kev kawm ntawv los yog leaching tov, thiab cov electromotive quab yuam tus nqi yog ntsuas, thiab ces hloov mus rau hauv tus nqi pH (acidity thiab alkalinity). Ntsuas ntawm acidity meter, tus nqi pH tuaj yeem nyeem ncaj qha tom qab cov txheej txheem daws teeb meem. Qhov sib piv ntawm dej-rau-av av muaj kev cuam tshuam ntau dua rau tus nqi pH, tshwj xeeb tshaj yog cov nyhuv dilution ntawm calcareous av. Nws yog ib qho tsim nyog yuav tau txais me me dej-rau-av ratio, thiab av pH yog 1: 1. Nyob rau tib lub sijhawm, hauv av acidic, ntxiv rau kev ntsuas ph nqi ntawm cov dej-soaked av, tus nqi ph ntawm cov ntsev-soaked av yuav tsum tau ntsuas, uas yog, cov av H ntxiv yog leached nrog 1molLˉ1 potassium chloride. daws thiab ces ntsuas los ntawm txoj kev potentiometric.
1.2 Daim ntawv thov thaj tsam ntawm online ph meter ntsuas Muaj feem xyuam rau kev txiav txim siab ntawm ntau yam av ph nqi.
1.3 Cov cuab yeej tseem ceeb thiab cov khoom siv rau kev ntsuas ph meter
① Acidity ntsuas; ②ph iav electrode; ③saturated calomel electrode; ④ lub tshuab nqus tsev.
1.4 ph meter ntsuas reagent
① 1molLˉ1 potassium chloride tov: Nyhav 74.6g ntawm poov tshuaj chloride (tshuaj lom neeg) thiab yaj nyob rau hauv 800ml dej, kho pH ntawm cov tshuaj rau 5.5-6.0 nrog dilute poov tshuaj hydroxide. thiab dilute hydrochloric acid, thiab dilute rau 1L;
② ph4.01 (25 degree) txheem buffer tov: Nyhav poov tshuaj hydrogen phthalate 10.21 uas tau qhuav ntawm 110-120 degree rau 2-3 teev, yaj nyob rau hauv dej, hloov mus rau 1L volumetric hwj, ua rau ntim nrog dej, thiab khaws cia rau hauv lub raj mis polyethylene;
③ pH6.87 (25 degree) standard buffer solution: Nyhav 3.533g ntawm disodium hydrogen phosphate thiab 3.388g ntawm potassium dihydrogen phosphate uas tau qhuav ntawm 110-130 degree rau 2-3 teev, yaj hauv dej, hloov mus rau 1L volumetric hwj, thiab dilute rau ntim nrog dej. Khaws rau hauv lub raj mis polyethylene;
④ pH9.18 (25 degree) txheem buffer tov: Nyhav 3.800g ntawm balanced borax (Na2B4O7·10H2O) thiab yaj nyob rau hauv CO2- dej dawb, hloov mus rau hauv 1L volumetric hwj, dilute nrog dej, thiab khaws cia rau hauv lub raj mis polyethylene;
Kev sib npaug ntawm kev kho mob ntawm borax: muab borax tso rau hauv ib lub desiccator uas muaj cov kua dej txaus ntawm sucrose thiab ntsev kom sib npaug rau ob hnub thiab hmo ntuj;
⑤ Distilled dej kom tshem tawm CO2.
1.5 pH meter ntsuas thiab ntsuas cov kauj ruam
① Instrument calibration: Cov kev siv ntawm ntau yam pH meters thiab potentiometers tsis zoo ib yam, thiab kev kho cov electrodes thiab siv cov twj paj nruag yog ua raws li cov lus qhia. Kho cov tshuaj yuav tsum tau kuaj thiab tus qauv buffer tov rau tib qhov kub thiab txias, thiab kho qhov kub thiab txias compensator rau tus nqi kub no. Thaum ntsuas qhov ntsuas nrog cov txheej txheem tsis haum, ua ntej ntxig cov electrode rau hauv cov txheej txheem tsis haum uas nws tus nqi pH tsis ntau tshaj 2 pH txawv ntawm cov qauv kuaj, pib qhov hloov pauv nyeem ntawv, kho qhov chaw kom nyeem ntawv tsuas yog pH tus nqi ntawm cov qauv kev daws teeb meem, thiab rov ua dua ob peb zaug Cia kev nyeem ntawv kom ruaj khov. Tshem tawm cov electrode thiab ntxuav nws, qhuav cov dej nrog ib daim ntawv lim, thiab tom qab ntawd muab tso rau hauv cov txheej txheem tsis haum. Qhov tso cai sib txawv ntawm ob txoj kev daws teeb meem yog 0.1ph chav tsev. Yog tias nws dhau, xyuas seb puas muaj teeb meem nrog lub ntsuas hluav taws xob lossis cov txheej txheem daws teeb meem. Cov cuab yeej siv tau los ntsuas cov qauv tsuas yog tom qab nws raug ntsuas kom raug.
② Kev txiav txim siab ntawm ph ntawm cov av dej immersion tov: Nyhav 20g (yam tsawg kawg nkaus 0.1g) ntawm cov qauv cua qhuav uas dhau los ntawm 2 hli aperture sieve rau hauv 50ml siab beaker, ntxiv 20ml dej uas tshem tawm CO2, thiab do. nrog rau stirrer rau 1min kom cov av hais kom tag nrho Disperse thiab ntsuas tom qab sawv rau 30min. Ntxig lub electrode rau hauv cov tshuaj yuav tsum tau kuaj (nco ntsoov tias qhov qis ntawm lub iav electrode qhov muag teev nyob rau hauv cov av-kua interface, thiab cov calomel electrode tau muab tso rau hauv cov kua dej ntshiab), co lub beaker maj mam tshem tawm cov dej. zaj duab xis ntawm lub electrode, thiab txhawb nqa nws ceev equilibrium. Txo qhov hloov pauv nyeem ntawv, thiab sau tus nqi pH thaum nyeem ntawv ruaj khov. Tso cov ntawv nyeem, tshem tawm cov electrode, ntxuav nws nrog dej, qhuav dej nrog ib daim ntawv lim, thiab tom qab ntawd ntsuas txhua tus qauv. Tom qab ntsuas 5-6 cov qauv, xyuas qhov chaw nrog cov qauv kev daws teeb meem.
③ Kev txiav txim siab ntawm tus nqi ph ntawm cov av poov tshuaj chloride ntsev extract: Thaum tus nqi pH ntawm cov av immersion yog<7, the ph value of soil salt extract should be measured. The determination method is except that 1molLˉ1 potassium chloride solution is used instead of CO2-free water, and the water-to-soil ratio is 1:1.
1.6 Kev suav cov ntsuas ph meter ntsuas thaum tus nqi pH ntsuas nrog pH ntsuas, tus nqi ph tuaj yeem nyeem ncaj qha yam tsis suav.
1.7 Kev ntsuas qhov tseeb ntawm ph meter Parallel tau tso cai ntau qhov sib txawv: nruab nrab thiab acidic av Tsawg dua lossis sib npaug rau 0.1ph chav tsev, alkaline av Tsawg dua lossis sib npaug rau 0.2ph unit.
1.8 pH Meter ntsuas ntsuas
① Cov iav electrodes uas tsis siv rau lub sijhawm ntev yuav tsum tau muab tso rau hauv dej rau 24 teev kom qhib tau ua ntej lawv tuaj yeem ua rau muaj kev cuam tshuam. Cov uas tsis siv ib ntus tuaj yeem ntub dej. Thaum lawv tsis siv sijhawm ntev, lawv yuav tsum tau khaws cia kom qhuav. Thaum lub iav electrode ntog, nws yuav tsum tau kho. Cov kab noj hniav ntawm calomel electrode yuav tsum tau ntim nrog cov tshuaj saturated potassium chloride, thiab yuav tsum muaj me ntsis potassium chloride crystallization nyob rau hauv chav tsev kub, tab sis cov poov tshuaj chloride crystallization yuav tsum tsis txhob ntau dhau, thiaj li tsis mus thaiv txoj kev ntawm cov electrode thiab cov tshuaj yuav tsum ntsuas. Yuav tsum tsis muaj huab cua npuas nruab nrab ntawm lub puab electrode ntawm lub iav electrode thiab lub teeb, thiab nruab nrab ntawm lub puab electrode ntawm calomel electrode thiab ceramic core.
② Txoj hauj lwm ntawm lub electrode nyob rau hauv lub ncua kev kawm ntawv muaj feem xyuam rau cov kev ntsuas. Nws yuav tsum tau ntxig cov calomel electrode rau hauv cov kua dej tsis meej thiab tsis txhob sib cuag nrog cov av nkos kom ntau li ntau tau kom txo tau qhov cuam tshuam ntawm calomel electrode kua hlws ris muaj peev xwm.
③ co lub beaker thaum lub sijhawm nyeem ph yuav ua rau kev nyeem ntawv tsawg, thiab koj yuav tsum tau tos me ntsis tom qab co ua ntej nyeem ntawv.
④ Tsis txhob nkag ntawm cov kua qaub thiab alkali chav thaum ua haujlwm.
⑤ Cov txheej txheem kev daws teeb meem tuaj yeem khaws cia rau 1 txog 2 lub hlis ntawm chav tsev kub, thiab lub sijhawm khaws cia tuaj yeem txuas ntxiv rau hauv lub tub yees ntawm 4 degree. Tsis txhob nchuav cov txheej txheem siv rov qab rau hauv cov tshuaj qub rau kev sib tov. Yog tias pom turbidity thiab nag lossis daus, nws tsis tuaj yeem siv dua.
⑥ Qhov ntsuas kub cuam tshuam rau lub peev xwm electrode thiab ionization tshuav ntawm dej. Qhov ntsuas kub ntawm qhov ntsuas kub ntawm qhov ntsuas kub, cov txheej txheem tsis sib haum thiab cov kev daws teeb meem yuav tsum tau ua kom zoo ib yam. Tus nqi pH ntawm tus qauv kev daws teeb meem hloov me ntsis nrog qhov kub thiab txias.
⑦ Thaum ntsuas cov qauv batch, nws yog qhov zoo tshaj rau cais cov qauv nrog qhov sib txawv loj ntawm pH tus nqi raws li hom av, thiab lwm yam, kom tsis txhob ntsuas qhov yuam kev tshwm sim los ntawm kev cuam tshuam qeeb ntawm cov electrode.
⑧ Yog tias cov qauv ntsuas nrog qhov ntom ntom, qhov sib piv ntawm cov dej-rau- av tuaj yeem hloov pauv me ntsis, tab sis nws yuav tsum tau qhia.
