VI. PHUdNC PHAP PHAN TicH el/e PH6: [6,7,8,16]
EO '= O+ 0,05 9I gaM(A)
o 0,059 '
t.E =-- - l g a M ( A )",t.E1/2=>EI/2+t.E1/2
n
AOO hUdng miy thuCJng duqe ap d\mg d@ dCJi E1/2eua dutV,OOftt hi dung d@ tach E1/2euanhi~udu tV eunghi~n di~ntrong dung dieh. Ph6itVAthuCJng duqe themVilO dudi hiOO thtien~neife ph6.
5.15.(fog d',lOg :Dung d@ diOO tiOO va diOO luqng
. Djnh tinh:
Trong di~u ki~n thife nghi~m xae diOO, ghi song eife ph6 eua dung dieh khao sat, diOOth~ ban song E1/2 eua du tV khao sat, so vdi tri s6 E1/2 eua dung diehehu~n duqe diOO trong eungmqtdi~u ki~n.
DiOOEI/2theo :
*DiOO di@m gilla eua dUCJng eongehu~ndq.
*Theo phuong triOO (9) ve gian d6 Ig (Igh - I) / I=n/O.059 (E - E1/2) theo E t~iE=El/2suy ra I=0,519hsuy ra Ig(Igh-I) / I=0, suy ra E1/2la giao di@m eua dUCJng bi@u di@n va tn,le hoaoo.
Song eua hai du tv xem OOu tach hoan toan khi 11 E1/2~250 mV
5.2. Djnh MjiJg:
DiOO Igh hay hgheua dung dieh khao sat so vdi Igh hay hgh eua dung dieh ehu~n dq trong eungdi~u ki~ntht!e nghi~m.Hai each diOO luqng thuCJng duqe ting d\mg la :
, , ?:~"
5.2.1. Phuong phap ltJp duong chuon :
Pha m(Hlo~idung dieh ehul{n, diOO Igh='f(C)hay hgh=f(C). DiOO hgh eua dung dieh mftu co hmttl do suy raCm'
*Phuong phap nay cae caekhuy~tdi@m sau :
- Phai tieuehu~nhoa nghiemng~tcaedi~u ki~nthifenghi~m - Phail~p l~idUCJngehu~nkhi thay d6idi~u ki~n.
5.2.2. Phuong phap them chwfn :
Do song eife ph6 eua hai dung dieh : Dung dieh mftu va dung dieh them ehu~n.
- GQi Cmla n6ng dq dung dieh mftu co them dung diehehu~n, ting vdi song co hm ,ta co :
hm=KCm h'm=K(C m+ Cc)
=>Cm= Cc. h'm - hm·
PhtWng phap khong phI) thuQe nhi~u vilO di~u ki~n thtfe nghi~m, nhung doi hoi ph:H cotll~ tuy~ntinh git1a hghva C trong khQ(lng tinhk~tqua.
- DQ nh<).y eua phuong phap tuy thuQe eUCJng dQ va dQI~pI<).i eua dong du. - DQ eh<;m IQe eua phuong phap tuy thuQen~netfe ph6.
- Sai s6 eua phuong phap khoang 2 - 3% vdi dung dieh co C=IO-J
- 10-4M; 5% vdi dung dieh co C=10-5M.
VII. GldI THItu VE PHU<1NG PHAP KiCHHO~TN<1TRON:[9,23]