giáo trình quan trắc mt

8/6/2019 Gio trnh quan trc MT

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Li gii thiu

Quan trc va phn tich mi trng (QT&PTMT) la mt hoat ng quan trong cua

cng tac quan ly nha nc v bao v mi trng. Tai cac iu 37 va 38 cua Lut Bao vmi trng a quy inh rng, B Khoa hoc, Cng ngh va Mi trng (nay la B Tainguyn Mi trng) chiu trach nhim trc Chinh phu v hoat ng quan ly nha ncv bao v mi trng va mt trong nhng ni dung c ban cua cng tac nay la: "Tchc, xy dng, quan ly h thng quan trc, inh ky anh gia hin trang mi trng, d

bao din bin mi trng."

thc hin cac quy inh trn cua Lut Bao v mi trng, t nm 1994, B KHCN&MT ( nay la B Tai nguyn & Mi trng) a tng bc xy dng Mang licac tram QT&PTMT quc gia. Mang li nay c xy dng trn c s phi h p lin

b nhm tn dung c cac nng lc sn co v QT&PTMT tai mt s b, nganh, iaphng va nhanh chong a c Mang li vao hoat ng phuc vu ki p thi cac yucu cp bach v quan ly mi trng. Ngoai Mang li QT&PTMT quc gia thi vai nmtr lai y, hang chuc ia phng trong nc cung bt u xy dng va bc u avao hoat ng cac tram QT&PTMT ia phng. Cung vi s phat trin cua hoat ngQT&PTMT thi nhu cu v b tai liu phap quy hng dn vic bao am va kim soatcht lng cua hoat ng nay ngay cang tr nn bc xuc.

Ban hng dn nay c soan thao nh la mt trong cac n lc cua Cuc Bao v mi trng, B TN&MT, trong vic am bao va kim soat cht lng cua hoat ng

QT&PTMT nhm a ra c cac s liu quan trc co tin cy va chinh xac cao.Ban hng dn y u se bao gm nhiu thanh phn mi trng khac nhau, ban

hng dn u tin nay soan thao cho quan trc mi trng nc luc ia bao gm 2chng :

Chng 1 - Nhng vn chung, bao gm cac khai nim c ban v quan trcmi trng va hoat ng am bao va kim soat cht lng trong quan trc mi trng

Chng 2 - Hng dn cu th v am bao va kim soat cht lng trong quantrc mi trng nc luc ia.

i tng ap dung Ban hng dn nay la tt ca hoat ng QT&PTMT c tinhanh trong Mang li quc gia va cac tram QT&PTMT ia phng. Ban hng dncung co th c s dung nh tai liu tham khao cho hoat ng QT&PTMT cua cacB/nganh khac.

Tai liu nay do Cuc Bao v mi trng chu tri bin soan vi s tham gia cua cacchuyn gia v quan trc va phn tich mi trng thuc cac n vi sau:

1. Trung tm ky thut mi trng thi va Khu cng nghi p, ai hoc Xy dngHa Ni

2. Tng cuc Tiu chun - o lng - Cht lng, B KHCN

3. Vin Khoa hoc va Cng ngh mi trng, ai hoc Bach khoa Ha Ni;


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Ban hng dn nay c coi nh c gng ban u nhng rt cn thit nhm nngcao cht lng va a dn vao n np hoat ng QT&PTMT tai Vit Nam. B tai liuhng dn v QT&PTMT se con c tip tuc hoan thin va b theo yu cu cua thct.

Do thi gian gp gap cng tac am bao va kim soat cht lng trong quan trcmi trng tai Vit Nam con rt mi me nn Ban hng dn chc chn con nhiu thiusot. Cuc Bao v Mi trng mong nhn c nhiu y kin ong gop cua cac chuyn gia,cac nha khoa hoc trong linh vc QT&PTMT cung nh cac linh vc lin quan tip tuctrin khai va hoan thin b tai liu quan trong nay.


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Chng 1

Nhng vn chung v bo m v kim sot cht lngtrong quan trc v phn tch mi trng

I.1. Mt s khai nim:

1. Quan trc mi trng (QTMT) la mt qua trinh o ac thng xuyn mt hocnhiu chi tiu v tinh cht vt ly, hoa hoc va sinh hoc cua cac thanh phn mi trng,theo mt k hoach l p sn v thi gian, khng gian, phng phap va quy trinh o lng, cung cp cac thng tin c ban co tin cy, chinh xac cao va co th anh gia cdin bin cht lng mi trng

2. Bao am cht lng (QA: Quality Assurance)trong quan trc mi trngla mth thng tich h p cac hoat ng quan ly va ky thut trong mt t chc nhm bao amcho hoat ng quan trc mi trng at c cac tiu chun cht lng a quy inh.

3. Kim soat cht lng (QC: Quality Control) trong quan trc mi trng la victhc hin cac bin phap anh gia, theo doi va ki p thi iu chinh at c chinh xac va t p trung cua cac phep o theo yu cu cua cac tiu chun cht lngnhm bao am cho hoat ng quan trc mi trng at cac tiu chun cht lng nay.

4. K hoach quan trc mi trngla mt chng trinh quan trc c l p ra nhm apng mt s muc tiu nht inh, trong o bao gm nhng yu cu v thng tin, cac thngs, cac ia im, tn sut va thi gian quan trc, cac yu cu v trang thit bi , phng

phap phn tich, o, th; yu cu v nhn lc va kinh phi thc hin.

Cac hoat ng QA/QC gn bo vi nhau, b sung cho nhau va mt s ni dungging nhau, cung din ra trong khun kh h thng quan ly cht lng cua t chc, viinh nghia h thng quan ly cht lng la c cu t chc, trach nhim, cac thu tuc, quatrinh va ngun lc cn thit thc hin quan ly cht lng.

II.2. am bao cht lng va kim soat cht lng trong quan trc va phn tichmi trng

1.2.1. QA/QC trong xac inh nhu cu thng tin

am bao cht lng chi co th thc hin tt khi cac yu cu v san phm c xacinh ro rang, cu th. Cac yu cu v quan trc va anh gia la nhu cu co tinh cht thng

tin (nhu cu thng tin). Nhu cu thng tin la im khi u trong chu trinh quan trc vaphn tich mi trng.

Nhu cu thng tin chung chung la khng co y nghi a. Nhng co nhng yu t lamphc ta p vic xac inh cac nhu cu thng tin, c bit la trong h p tac quc t v quantrc va anh gia mi trng. Vi du: thiu cac thut ng, inh nghia cn thit; s go bodo chuyn nganh cua cac chuyn gia; nhng thoa thun phai at c...

Nhu cu thng tin phai phan anh chinh sach hin hanh v quan ly mi trng vaphai bao ham c nhng cn nhc, xem xet co tinh cht lu dai. C s u tin xacinh nhu cu thng tin la cac lut va cac vn ban thoa thun tm quc gia va quc t.

Ngoai ra, nhng yu cu phuc vu vic soat xet cac quy inh, vic xy dng mt chinh


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sach mi, quan im cua cac nha quan ly hin hanh, cung la nhng c s xac inhnhu cu thng tin.

Hinh 1. Cac bc chu yu trong quan trc va phn tich mi trng

1.2.2. QA/QC trong xac inh chng trinh quan trc

T nhu cu thng tin, phai xac inh muc tiu va nhu cu quan trc cu th, tc laphai xac inh mt chin lc cho vic quan trc.

Chin lc quan trc phai quyt inh ro loai quan trc cn thit: vt ly, sinh hoc,hoa hoc, thuy vn, cht thai hoc canh bao sm ... Phai qui inh cac thng s cn quan

trc, chinh xac va tin cy cn thit v.v... Con vic thit k mang li se xac inh nophai c quan trc nh th nao. Chin lc quan trc cung phai bao gm ca vic phntich s liu va bao cao, vi nhng cng vic nay co th co anh hng ti cac yu cu cuavic thit k mang li quan trc. Chin lc quan trc phai c lam thanh tai liu vacn c nhng ngi hay c quan co thm quyn ra quyt inh ph duyt

Cac thanh phn cua mt bao cao chin lc quan trc la:

1. Cac nhu cu thng tin bao gm trong chin lc quan trc va phn nhu cuthng tin se khng bao gm trong chin lc quan trc.

2. Khai nim v h thng quan trc va i tng quan trc (vt ly, hoa hoc, sinh

hoc, thuy vn, cht thai...), cac thng s cn quan trc va cac iu kin ban u la

Quan ly mi trng

Phn tich trong PTN

Nhu cu thng tin S dung thng tin

Chng trinh quan trc

Thit k mang li

Bao cao

Phn tich s liu

Ly mu va quan trc taihin trng

X ly s liu


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chon ia im va tn sut ly mu i vi tng bin s (nh khoang cach ln nht/ benht tinh t ng bin; tin cy...).

3. Khai nim v h thng anh gia, vi du nh cac phng phap tinh toan c sdung ( tinh toan mc e doa hoc khuynh hng); cac tiu chun quc t phu h p

nht; vic s dung thi , cng cu thng k va cac cng cu khac trinh bay s liu.4. Cac khia canh v mt t chc: t chc nao se chiu trach nhim v mt nao cua

h thng quan trc; nhng thay i cn thit trong t chc, nhng kho khn cho victhc hin h thng quan trc v.v... s h p tac gia cac b phn, c quan thc hin.

5. K hoach thit k va thc hin mang li quan trc; nhng iu kin banu la gi, k hoach cua nhng bc tip theo va k hoach tai chinh.

6. S phn tich v cac rui ro; nhng vn co th dn ti cac tht bai cua h thng quan trc va nu ln bin phap khc phuc.

1.2.3. QA/QC trong thit k mang liThit k mang li phai c mt nhom chuyn gia co kin thc a nganh thchin. Thit k mang li cn xac inh thng s nao phai quan trc, quan trc ia imnao va vi tn sut bao nhiu. Trong thit k mang li cung cn c p ti vic sdung cac phng phap ly mu, cac phng phap phn tich trong phong thi nghim vacac phng phap x ly s liu.

Cn c bit quan tm n vic ng dung thng k trong thit k mang li. Vics dung thng k hoc co th lam giam n mc ti thiu cac ia im thng qua mitng quan gia cac tram. Thng k hoc cung la c s chon la gia hai phng an:nhiu ia im vi tn sut thp hoc it ia im vi tn sut cao.

Mt vn quan trong trong thit k mang li la xac inh tinh hiu qua cuathng tin nhn c t mang li. Cn co s hiu bit chi tit v chi phi va hiu qua cuamang li a thit k.

Thit k mang li phai c tai liu hoa bng mt vn ban. Vn ban nay phaichuyn ti nhng ngi phu trach va quan ly chin lc quan trc quc gia. T vn bannay ho se rut ra kt lun la mang li quan trc co nm trong chin lc va muc tiuquan trc chung hay khng.

Bao cao thit k mang li gm cac phn sau:

1. Giai thich phn chin lc quan trc c c p n trong thit k mang liva phn cua thit k mang li khng co trong chin lc quan trc.

2. M ta mang li quan trc: cac bin s cn o; cac ia im ly mu va tnsut; vic s dung cac tiu chun, vi du TCVN; ISO...

3. Cach thc trinh bay va th hin cac kt qua.

4. Cac khia canh v mt t chc. Vi du nh nhim vu cua cac t chc tham giai vi tng bc khac nhau trong chng trinh quan trc: thu th p, x ly va vnchuyn mu, phn tich trong phong thi nghim; x ly s li u; phn tich s liu; baocao...

5. K hoach thc hin cua mang li quan trc.


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6. Cac kt qua phn tich chi phi- hiu qua; m ta cac tranh lun ra quyt inh.

7. Phn tich cac rui ro. Cai gi se xy ra nu co sai sot va cac bin phap nao co ththc hin tranh hoc giam thiu cac thit hai.

1.2.4. QA/QC trong hoat ng tai hin trng

Hoat ng tai hin trng bao gm ly mu va quan trc hin trng. Tuy thucvao thanh phn mi trng ma co cac phng phap tin hanh khac nhau.

1.2.5. QA/QC trong hoat ng phong thi nghim

QA/QC phong thi nghim chinh la vic xy dng va ap dung h thng quan lycht lng trong o co s an xen, kt h p cac hoat ng QC, theo yu cu cua ISO/IECGuide 25 TCVN 5958: 1995, Yu cu chung v nng lc cua phong th nghim/hiuchun hin nay a c chuyn thanh mt tiu chun quc t mang tn ISO/IEC 17025:1999, tng ng vi TCVN ISO/IEC 17025: 2001.

1.2.6. QA/QC trong xly s liuTrong mt chng trinh quan trc, s liu thu c s dung thng la rt ln.

thun li cho s dung, hu ht cac s liu ngay nay u c lu gi trong cac files liu cua may tinh. Co hai loai s liu c lu gi. Mt loai a c lu gi sntrong may tinh va mt loai la nhng s liu o c cua chng trinh quan trc hinhanh. Phai am bao cho cac loai s liu nay c phn bit ro rang, khng nhm ln vinhau va an toan.

Khi s dung phn mm cua may tinh, cn phai c bit quan tm n vic kimtra, phat trin va duy tri h thng may tinh. Phn mm cua may tinh cung co th thc

hin cac chc nng kim soat khac nhau, nh cac phep phn tich tng quan va vic sdung cac c p gii han.

1.2.7. QA/QC trong phn tich s liu

Phn tich s liu la giai oan chuyn s liu th thanh thng tin s dung c. nhng thng tin nhn c t s liu th co th so sanh va truy nguyn ngun gc, phaitrin khai cac bin ban phn tich s liu.

Phai co phng phap t liu hoa chun mc nhm bin cac s liu a co thanh cs d liu truy c p va x dung khi cn thit.

1.2.8. QA/QC trong l p bao cao

Muc tiu cui cung cua mt chng trinh quan trc la chuyn thng tin a thu th pc ti ngi s dung thng tin. Co th thc hin cng vic nay bng nhiu cach khacnhau: truyn toan b cac phep phn tich s liu hoc chi la nhng kt lun ngn gon

bng vn ban, li noi hoc bang s... Mt s ky thut trinh bay s liu c s dungrng rai la:

1/ Cac bang s liu o

Cach lit k s liu o vao trong cac bang tao iu kin khng lam mt s liu.Tuy nhin, t cac s liu trong bang, ngi oc s liu phai t tao thanh cac thng tin

cn thit cho minh.2/ S liu o c x ly thng k


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X ly thng k se chuyn i s liu ri rac thanh cac gia tri h thng thay itheo thi gian va khng gian. Chung tao ra thng tin co th s dung ngay cho ngi oc.

3/ thi

thi giup cho ngi oc nhanh chong rut ra c nhng nhn inh tng quat.Bng vic nu ra cac tiu chun hoc cac tai liu tham khao trn thi, tinh hinh mitrng c phan anh ung thc trang cua no. Cac thi co th la dang ng, dang cthoc biu phn trm (% )...

4/ Thng tin c trinh bay co tinh cht ia ly

Cach trinh bay nay giup hiu bit tt hn tinh hinh cht lng cua mi trng quaphn b khng gian cua cac thng s lin quan.

5/ Thng tin tng h p

Vic tng h p lai cac s liu la rt cn thit x ly nhanh mt lng ln s liu.

S dung cac phu luc la phng phap hay c dung ap ng yu cu nay.

Chng 2


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Hng dn am bao cht lng/kim soat chtlng (QA/QC) trong quan trc va phn tich mi

trng nc luc ia

II.1. Tng quan v bao am va kim soat cht lng trong quan trc nc lucia

II.1.1. Muc tiuCac hoat ng quan trc va phn tich mi trng nc din ra ngoai hin trng

(ly mu, bao quan mu, o ac mt s thng s khng bn) va phn tich trong phongthi nghim. thu th p c thng tin cn phai tin hanh mt loat hoat ng bao gmt khu l p k hoach, thit k chng trinh, thit k mang li, ly mu, phn tich trong

phong thi nghim va x ly s liu.

Muc tiu cua chng trinh am bao cht lng/kim soat cht lng (QA/QC) tronghoat ng quan trc va phn tich mi trng nc (bao gm nc luc ia va nc bin)la cung cp nhng s liu tin cy va a c kim soat v hin trang mi trng nc

bao gm cac thng s chu yu nh: nhit , pH, DO, kim loai nng, cn l lng, uc, COD, BOD5/TOC (vi nc bin), clorua, amoni, tng P, tng N, tng coliform,trm tich, phu du, vi sinh vt... thoa man yu cu thng tin cn thu th p, theo muc tiucht lng t ra, :

anh gia hin trang cht lng nc khu vc/ia phng;

anh gia din bin cht lng mi trng nc theo thi gian;

Canh bao sm cac hin tng nhim ngun nc;

Theo cac yu cu khac cua cng tac quan ly mi trng va phat trin kinh t.

II.1.2. QA/QC trong lp k hoach/thit k chng trinh

Khi l p k hoach quan trc phai bao ham cac ni dung chinh nh sau:

Xac inh ni dung nhim vu t quan trc: ia im/tram vi , cac thng s cn oac, cac loai mu cn ly, thi gian thc hin.

Xac inh yu cu v nhn lc tham gia (s lng, linh vc chuyn mn).

Yu cu v trang thit bi .

L p k hoach ly mu.

Phng phap ly mu va phn tich.

Kinh phi cho chng trinh quan trc va QA/QC

Cac vn am bao an toan con ngi, thit bi cho cac hoat ng quan trc nhtla quan trc trn sng, bao gm:

- Cac bin phap, phng tin bao am an toan (ngi va thit bi);

- Phng an cu h;


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Mt k hoach am bao cht lng ly mu cn phai c thit l p, bao gm:

Cac nhn vin ly mu u a c ao tao va t p hun.

Chun bi cng tac thc ia chu ao: dung cu, thit bi , hoa cht thuc th baoquan mu phai y u va phu h p.

am bao rng cac phng phap ly mu u c ph bin ti tt ca cac nhnvin trong nhom quan trc.

am bao rng mi mt bc ly mu hin nay va qua trinh ly mu trc yu tun theo mt vn ban.

am bao rng dung cu ly mu va may moc o ac hin trng phai c baotri va hiu chun inh ky, s sach bao tri cn phai c lu gi.

Quy inh thng nht v nhn dang mu c ly bao gm dan nhan ln tt ca cacmu c ly, trn o ghi chep chinh xac ngay thang, ia im, thi gian ly mu va tnngi ly mu, s ma hiu cua mu bng mc khng thm nc.

Quy inh v ghi chep lai tt ca cac chi tit co lin quan n vic ly mu vao binban/nht ky ly mu, nhng iu kin va cac bin ng bt thng t ky thut ly muthng thng n nhng yu cu c bit.

Quy inh v iu kin,ni cac dung cu tranh lam nhim bn mu, lam sach dung cu ly mu, kim tra sach va hiu qua cua dung cu (bng cach phn tich mu trng va mu so sanh thich h p).

Quy inh v tin hanh bao quan mu cho tng thng s cht lng nc, trm

tich, phu du, vi sinh vt ... theo cac chi dn trong cac tiu chun tng ng. Bao am chinh xac cua cac phep o, phn tich ngoai hin

trng khi cac iu kin mi trng khng c am bao. Cac thng s hin trng(nhit , m, ap sut...) cn phai ghi chep khi ly mu chuyn i cac gia tri oc v iu kin tiu chun khi l p bao cao, thi du: s liu pH phai chuyn v iukin 250C.

Cn phai m ta chi tit:

Qua trinh trao i chi tit cho nhng ngi cha co nhiu kinh nghim vn cou kha nng hoan thanh vic ly va x ly mu;

Qua trinh chun bi thuc th va bao quan; Hng dn s dung dung cu ly mu, may o hin trng ... b xung cho cac tai

liu vn hanh cua nha san xut;

Phng phap chun bi mu QC;

Tiu chi kim soat cht lng ( nghia la gii han chp nhn);

Phng phap ly mu va cac tai liu cn phai xem xet thng xuyn va khng cqua 1 nm/mt ln. Phng phap cn phai c ph duyt lai theo inh ky c bit cos thay i v thit bi hoc con ngi.

Khi tai liu c lu gi trong cac file may tinh, nhng thay i v phng phap lymu cn phai c phan anh bng cach thay i cac ma s may tinh co lin quan.


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Nguyn nhn gy ra sai s do ly mu:

Nhng nguyn nhn gy ra sai s do ly mu co th la:

Nhim bn:

Nhim bn do cac thit bi ly va cha mu gy ra; do dung cu cha mu bn; do s ly nhim gia cac mu; do cach bao quan, lu kho va b tri vn chuyn mu khngthich h p.

Tinh khng n inh cua mu:

- Ban cht cua mu

- Tng tac cua mu vi dung cu khac

- anh hng cua nhit , anh sang

Ly mu khng chinh xac:

- Quy trinh ly mu khng phu h p,

- Khng tun thu ung quy trinh ly mu.

Vn chuyn mu:

- Do thi gian vn chuyn mu qua gii han cho phep,

- Do iu kin vn chuyn khng phu h p.

II.2.2. Kim sot cht lng hin trng

Kim soat cht lng hin trng yu cu phai tin hanh ly cac loai mu trng,

mu up nhm kim tra mc tinh khit cua hoa cht dung lam cht bao quan, kimtra mc nhim bn cua dung cu ly, cha mu, giy loc hay cac thit bi khac co linquan n cng vic thu, bao quan va vn chuyn mu. Mu l p cung c thu nhmkim tra mc tai l p cua vic ly mu. Thi gian va tn xut ly mu trng, mu upva mu l p c xac inh khi thit k chng trinh. Noi chung khoang 10 ln thu mu,tin hanh thu 1 ln cac loai mu trng, mu up, mu l p. Cach thc va y nghia thu cacloai mu nh sau:

a, Mu trng dung cu cha mu

Ly mt dung cu cha mu mt cach ngu nhin, sau o na p dung cu bng nc ct

mang ra hin trng. Mu nay c bao quan, vn chuyn va phn tich cac thng strong phong thi nghim tng t nh cac mu thng thng. Mu trng loai nay nhmkim soat s nhim bn do qua trinh ra, bao quan dung cu.

b, Mu trng dung cu ly mu

Dung nc ct trang hoc vao dung cu ly mu. Sau o na p vao chai cha mu.Mu c bao quan, vn chuyn va phn tich cac thng s tng t nh mu cn ly.Mu loai nay nhm kim soat mc nhim trong qua trinh bao quan, s dung dungcu ly mu.

c, Mu trng thit bi loc mu


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Nu mu nc cn loc ngoai hin trng xac inh cac h p phn hoa tan thi cacb loc mu se c ra, bao quan va vn chuyn ngoai hin trng. Tin hanh ly mutrng dung cu loc mu bng cach: cho nc ct hai ln loc qua dung cu loc mu. Phnloc c na p vao dung cu cha mu va c bao quan vn chuyn v phong thi nghimtng t nh cac mu a ly phn tich cac thng s mi trng.

d) Mu trng vn chuyn va mu trng hin trng

Mu trng vn chuyn: cho vao dung cu cha mu mt lng nc ct tinh khithoc nc a kh ion, y kin np, chuyn t phong thi nghim ra ngoai hin trng vac vn chuyn cung vi mu tht. Mu trng vn chuyn dung xac inh s nhim

bn co th xy ra khi x ly, vn chuyn va bao quan mu.

Mu trng hin trng: cho vao dung cu cha mu mt lng nc ct tinhkhit/nc kh ion va chuyn t phong thi nghim ra ngoai hin trng. Tai hin trngnp dung cu cha mu c m ra va x ly ging nh cac mu tht. Mu trng hin

trng dung xac inh s nhim bn gy ra t cac dung cu ly mu, dung cu x lymu (cac loai mang loc) hoc do cac iu kin khac cua mi trng trong qua trinh lymu (do bui bc ln chng han).

Co th m ta cach thc chun bi mu trng theo s nh sau:

Cac thng tin v mu trng hin trng, mu trng vn chuyn cn phai c th

hin trong bao cao cung vi mu tht. Khi cac cht gy nhiu a c nhn bit cnphai iu tra tng nguyn nhn va ki p thi khc phuc.

e) Mu up (mu chia i)

Mu up c thu bng cach chia mt mu thanh 2 hay nhiu mu ging nhau.Mu nay s dung anh gia cac sai s ngu nhin va h thng do co s thay i trongthi gian ly va vn chuyn mu v phong thi nghim.

f) Mu l p theo thi gian

Ly hai hoc nhiu mu tai mt ia im. Mu loai nay anh gia s bin ng

theo thi gian cua cac thng s mi trng trong khu vc. g) Mu l p theo khng gian

Nc ct tinh khit

Phn A(Gi lai trong phong TN) Phn B (Chia lam haiphn)

Mu trng hin trng(X ly nh mu tht)

Mu trng vn chuyn(Khng x ly)


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Ly hai hoc nhiu mu cung mt luc trn mt lat ct ngang a c xac inh trctrong thuy vc. Mu loai nay dung anh gia s bin ng theo khng gian cua cacthng s mi trng.

h) Mu chun i chng hin trng:

Mu chun i chng vn chuyn la mt lng nc tinh khit co cha cht phntich (cht chun) bit trc nng c chuyn t phong thi nghim ra hin trngsau o quay tr v cung vi mu tht. Tai hin trng khng m np y mu. Muchun i chng vn chuyn dung xac inh ca s nhim bn va s mt mat cht phntich co th xay ra khi x ly mu, vn chuyn va bao quan mu ng thi cung xacinh sai s phn tich.

Mu chun i chng hin trng la lng nc tinh khit co cha cht phntich (cht chun) bit trc nng c mang t phong thi nghim ra ngoai hintrng. Tai hin trng, np y c m ra va tin hanh x ly nh mu tht. Muc ich

cua vic tao mu chun i chng hin trng la xac inh s nhim bn hoc s mtmat cht phn tich xay ra do dung cu ly mu, dung cu x ly mu va anh hng cua iukin mi trng trong sut qua trinh ly mu cho v n phong thi nghim.

Cac kt qua phn tich mu chun i chng hin trng cn phai c a vao baocao cung vi mu tht. Khi xy ra s sai lch vi gia tri thc khng c chinh sa sliu ma cn phai tin hanh iu tra va khc phuc ki p thi.

i) Mu l p hin trng

La hai (hoc nhiu hn) mu c ly tai cung mt vi tri, s dung cung mt thit bi lymu va c cung mt can b tin hanh, c x ly, bao quan, vn chuyn va phn tich

cac thng s trong phong thi nghim tng t nh mu tht. Mu QC loai nay c sdung kim soat chum cua vic ly mu ngoai hin trng.

k) Mu thm

Vic thm cht phn tich (cht chun) a bit trc nng vao nc ct hay nckh ion cung thi im ly mu ngay tai hin trng xem xet s phn huy cac thngs k t khi ly mu.

Mu thm c s dung khi bt u mt ky thut mi hoc thit bi mi bao amrng phng phap hoc thit bi la thich h p cho cac mu ang c ly co tinh phc ta pnh vy. Vic thm cht chun vao mu phai do nhng can b phn tich co kinh nghimthc hin.

II.2.3. QA/QC trong vn chuyn mu

II.2.3.1. am bao cht lng

Vn chuyn mu: cn phai co quy trinh vn chuyn mu phu h p nhm bao toanmu v mt s lng va cht lng. Trong quy trinh cn nu ro mt s im chinhnh sau:

- Mu khi vn chuyn phai co nhan (ky hiu) tranh nhm ln.

- Thu tuc sp xp mu nhm tranh v.


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- Yu cu trong qua trinh vn chuyn: thi gian vn chuyn va nhit cua mu, yucu nay da theo tiu chun (TCVN, ISO) i vi tng thng s quan trc va cach

bao quan mu (bang 2.1).

Bng 2.1. Yu cu khi vn chuyn mu

TT Tn mu Cac yu cu khi vnchuyn

Ghi chu

- Phng tin vn chuyn: c xac inh trn c s yu cu cua thng s quan trc(Bang 2.2).

Bng 2.2. Phng tin vn chuyn v ngi chiu trch nhim

TT Tn mu Phng tinvn chuyn

Ngi chiutrach nhim

Thi gianvn chuyn

Ghi chu

Giao va nhn mu: co th c tin hanh hin trng (nhom hin trng ban giaocho ngi vn chuyn, va phong thi nghim (nhom hin trng hay ngi vnchuyn ban giao cho phong thi nghim)) theo quy trinh vi ni dung c th hin

trong bin ban ban giao:- Ho va tn ngi ban giao:

- Ho va tn ngi nhn:

- Thi gian ban giao:

- S lng mu:

- Tinh trang mu khi ban giao:

- Ghi chu (nhng im bt thng cn quan tm):Kim tra va loai bo cac mu khng at yu cu nh v, bt nut,... va tin hanh

khi phuc lai cac mu bi sai sot nu co th.Khi tip nhn mu, phai ban giao y u v s lng, bao am cht lng, ghi chep

ro rang v tinh trang mu, nhng sai hong trong qua trinh vn chuyn

II.2.3.2. Kim soat cht lng

kim soat cht lng trong qua trinh vn chuyn mu, mu kim soat cht lngthng c s dung:

Mu trng vn chuyn: mt mu nho vt liu sach cua i tng nghin cu cvn chuyn cung vi mu tht trong cung mt mi trng, c bao quan, phn tich cacthng s trong phong thi nghim nh mu tht. Mu QC loai nay c s dung kimsoat s nhim bn trong qua trinh vn chuyn mu.


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II.2.4. QA/QC trong o, phn tch tai hin trng

Mt s thng s khng bn nh nhit , pH, DO, cht rn l lng, uc cn cxac inh tai ch hoc ngay sau khi ly mu cang sm cang tt.

Khi o, phn tich tai ch cac thng s khng bn, cn phai chu y:

La chon phng phap phn tich phu h p khng hoc it bi anh hng cuaiu kin bn ngoai hoc tao cac iu kin mi trng thich h p (nh phong thi nghimdi ng, b tri bung lam vic trn tau ...) bao am kt qua phn tich.

Nhng thay i bt thng khi ly mu

Tinh trang hoat ng cua thit bi

Ngn nga nhim bn mu:

- o ac hin trng: Khi o ac cac thng s bng may moc ngoai hin trng (vidu pH, to, mn,...) khng c nhung trc tip cac thit bi o vao may ly nc ma

phai ly cac mu phu o, sau khi o, mu o phai i.

- Chai lo cha mu phai c ra sach theo ung yu cu i vi tng thng s.Khng c tn dung cac loai chai lo a dung cha hoa cht trong phong thi nghim s dung cho vic cha mu.

- Dung cu cha mu phai c bao quan trong mi trng sach se, tranh bui, khoi vacac ngun gy nhim khac.

- Cac loai giy loc, b dung cu loc phai c ong goi cn thn, boc bng cac chtliu thich h p.

am bao cac thit bi hoat ng quan trc ngoai hin trng lam vic chinh xac ninh, cn phai inh ky hiu chun cac thit bi nay theo cac quy inh cua nha san xut.Tt ca h s hiu chun phai c lu gi.

Trong trng h p khng co iu kin hiu chun thi phai co cac bin phap nhnbit tinh trang lam vic cua thit bi o. Thi du: so sanh thng xuyn gia cac thit biging nhau hoc cung loai vi nhau theo mt chi tiu phu h p.

Trc mi t quan trc cn phai kim tra tinh trang hoat ng cua thit bi .

i vi nhng mu c phn tich tai hin trng (cht rn l lng, uc ...) cungphai tin hanh phn tich mu QC kim soat c cht lng s liu.

II.2.5. Thuc th ho cht bo qun mu

Toan b thuc th va hoa cht bao quan mu phai at tinh khit theo yu cu cuamc phn tich va co nhan dan ro rang

Hoa cht va thuc th bao quan co th c ong o trc va cho vao cac lo nhohoc ampul va han kin tranh phai pha ch ngoai hin trng.

II.2.6. Nc ct

Nc ct s dung ngoai hin trng cn phai chu y:


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18/41


19/41

Mu thm hin trng c so sanh vi mu thm phong thi nghim phn bitcac vn bao quan va vn chuyn mu ngoai hin trng va cac vn bao quan mutrong phong thi nghim.

Mu l p ngoai hin trng c so sanh vi mu l p trong phong thi nghim

phn bit chun xac cua vic thu mu ngoai hin trng vi chun xac cua phntich trong phong thi nghim.

kim soat cht lng s liu, phong thi nghim phai duy tri phn tich mu QC,bao gm:

Mu trng thit bi (Blanks): s dung nc ct lam mu trng nhm anh gia nhiu cua thit bi va xac inh gii han phat hin cua thit bi . Gii han phat hin cua thit

bi theo quy inh bng 3 ln nhiu ng nn.

Mu trng phng phap (Method Blanks): s dung nc ct + cac cht chun bi mu (hoa cht tao mi trng, hoa cht che, thuc th hin mau ...) nhng khng co

cht inh phn tich. Mu trng phng phap anh gia gi han phat hin cua phngphap, anh gia mc tinh khit cua hoa cht s dung.

Mu l p (Replcates/Duplicates): Do tinh phc ta p cua cac phng phap phn tichmu nc nn ta khng th lam c tt ca mu l p anh gia lch chun cung nh khng am bao cua phep o. Nn nh a c p trn chung ta chi lam mt s mul p/mu up cho mt nhom mu (15U20 mu) anh gia t p trung cua phep th.

Chun thm tra (Control Standards)

Chun so sanh (Refrence Standards)

Mu chun i chng(CRMs): Vi mi trng nc, mu chun i chng thngthng la cac mu ly tai hin trng hoc cac mu t tao co thanh phn phc ta p nhngoai mi trng, c a n nhiu phong thi nghim co uy tin xac inh gia tri trung binh va khoang tin cy. Mu chun i chng c lam song song vi mu thc.Cn c vao khoang tin cy o cho phep ta anh gia kt qua phn tich mu thc. S liu

phn tich mu chun i chng cn phai lu trong h s di dang biu kim tra anh gia hiu qua cung nh sai s h thng cua phng phap.

Mu ng hanh (Surrogate Compounds): mu ng hanh la cac mu co c imnh mu tht, cac cht phn tich trong o cung co tinh cht vt ly hoa hoc tng t vicac cht trong mu tht nhng lai khng co trong t nhin, hoc s dung cac cht ng

vi phong xa trong thanh phn nguyn t cua cac cht phn tich (14

C,37

Cl...). Mu nghanh thng s dung khi phn tich cac h p cht hu c nh PAHs, thuc tr su.Kt qua thc hin phn tich mu QC c i kem vi s liu chng trinh quan trc

va phn tich mi trng va trinh bay nh bang sau:

Mu Kt qu

Mu trng thit bi:Mu trng phng phap:Chun thm tra:Mu No.1:Mu No.2:............


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Mu No.n :Mu l p No.2:Mu l p No.m (m n)Mu trng phng phap:CRM/Mu ng hanh:Chun so sanh:

II.4. QA/QC trong tinh toan kt qua, ghi chep s liu phn tich

Cac kt qua phn tich trc khi ghi chep vao s phai c kim tra i chiu vi cac ssach gc nh: nht ky thc ia, s ghi kt qua phn tich. Vic kim tra c thc hin

bi it nht 1 ngi co trach nhim trong phong thi nghim. Kt qua phn tich c ghivao biu kt qua phai cha ng c mt s thng tin quan trong di y:

Ngay thang phn tich, phng phap phn tich.

Ky hiu mu phn tich. Ky hiu va kt qua phn tich cua mu kim tra.

Cac gii han kim tra va canh bao.

Cac sc , thi (nu co).

Ho tn ngi phn tich, ngi tinh toan va ngi kim tra.Sau khi s liu c i chiu, kim tra, luc o mi co gia tri va c s dung vao cacmuc ich khac nhau.

II.5. QA/QC trong bao cao kt qua

Ban bao cao kt qua phn tich am bao cht lng phai bao gm cac thng tin sau:- Tiu - Tn, ia chi phong thi nghim tin hanh phn tich- Tn, ia chi khach hang- Ngay, thang ly mu- Ngay, gi phn tich- Ky hiu mu.- Tinh trang mu khi a vao phn tich

- Phng phap phn tich a s dung- Sai s cho phep- Kt qua phn tich mu trng thit bi , mu trng phong thi nghim, mu up va mul p

- Kt qua phn tich mu


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Ti liu tham kho

1. APHA, Standard Methods for the Examination of Water and Wastewater, 19thEdition, 1995

1. Britsh Columbia Field Sampling Manual, 1996 Edition2. Canadian Executive Agency, CPMS-II, Pollution Monitoring and Baseline

Studies- Environmental Monitoring Workbook 1997.3. EPA Standard Methods, CD-ROM, Revision 1, July 19922. ISO 5667-14:1998, Water Quality- Sampling, Part 14: Guidance on Quality

Assurance of Enviromental Water Sampling and Handling3. IUPAC, ISO, AOAC, Harmonised Guidlines for Internal Quality Control in

Analitycal Chemistry Laboratory, 1994

4. Jame P.Dux,Quality Assurance for the Anlytical Chemistry Laboratory, 2dEdition, Van Nostrand Reihold, 19915. Lawrence H.K. et all, Principles of Environmental Analysis, Ana.Chem, 1983,

55, 2210-22186. TCVN 5993-1995, Cht lng nc-Hng dn bao quan va x ly mu7. TCVN 5994-1995, Cht lng nc-Hng dn ly mu h ao t nhin nhn

tao8. TCVN 5996-1995, Cht lng nc-Hng dn ly mu nc sng va sui9. TCVN 5998-1995, Cht lng nc-Hng dn ly mu nc thai

4. UN/ECE Task Force on Monitoring & Assessment, Guidelines on Water-Qualitymonitoring and Assessment of Tranboudary Rivers, May 19965. UN/ECE Task Force on Monitoring & Assessment, Volumn 4: Quality

Assurance, Jaunuary 19966. Villars M.T. Monitoring water quality in the future, Executive summary, Deft,

the netherlands, May 1995.


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Phu luc 1: H thng quan ly cht lng phong thi nghim

H thng quan ly cht lng cua phong th nghim/ hiu chun c quy inhtrong ISO/IEC 17025: 1999 gm hai nhom yu cu ln: cac yu cu v quan ly va cacyu cu v ky thut.

Cac yu cu v quan ly bao gm:

1. T chc.

2. H thng cht lng.

3. Kim soat tai liu.

4. Xem xet cac yu cu, nghi va h p ng.

5. H p ng phu v th nghim va hiu chun.

6. Cac dich vu mua sm va ngun cung cp.

7. Dich vu i vi khach hang.

8. Phan nan (hay kin nghi).

9. Kim soat vic th nghim va/hoc hiu chun khng phu h p.

10. Bin phap khc phuc.

11. Bin phap phong nga.

12. Kim soat h s.

13. anh gia ni b.

14. Xem xet cua lanh ao.

Cac yu cu v ky thut bao gm:

1. Yu cu chung.

2. Nhn s.

3. Tin nghi va iu kin mi trng.

4. Phng phap th nghim, hiu chun va ph duyt phng phap.

5. Thit bi .

6. Tinh lin kt chun o lng.

7. Ly mu.

8. Quan ly mu th nghim, hiu chun.

9. am bao cht lng kt qua th nghim va hiu chun

10. Bao cao kt qua.

Di y hng dn thc hin mt s vn then cht trong hoat ng QA/QCcua phong thi nghim.

I. T chc v qun ly phong th nghim


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t chc va quan ly tt phong thi nghim, cn thc hin mt s yu cu sau:

a/ Xac inh ro c cu t chc cua PTN trong t chc ma PTN trc thuc. Phninh ro nhim vu, trach nhim cua tng can b, nhn vin trong PTN. Xac inh cu thngi la "can b quan ly ky thut" chiu trach nhim v cac hoat ng ky thut va ngila "can b quan ly cht lng" chiu trach nhim am bao cho cac yu cu a c quyinh trong h thng cht lng c tun thu va thc hin y u.

b/ Phong thi nghim phai thit l p mt h thng cht lng c th hin bng h thng cac vn ban, tai liu, goi chung la "h thng tai liu cht lng". H thng tai liucht lng nay bao gm: S tay cht lng; cac quy inh, thu tuc iu hanh nhng hoatng, qua trinh co tinh cht chung cua phong thi nghim; cac quy inh, tai liu co tinhcht chi dn cng vic cu th.

Co th hinh dung h thng tai liu cht lng trn bng s kim t thap diy. trn cung la S tay cht lng, cang mc di, s lng vn ban, tai liu cangyu cu nhiu hn.

c/ PTN phai inh ky tin hanh vic anh gia ni b theo cac thi han (thng la 1

nm) va thu tuc a inh kim tra xem hoat ng cua phong thi nghim co lin tuctun thu cac yu cu cua h thng cht lng hay khng. Can b quan ly cht lng cotrach nhim l p k hoach va t chc anh gia theo chng trinh a inh.

Khi vic anh gia phat hin ra nhng nghi ng v hiu qua cua cac hoat nghoc v s ung n cua cac kt qua phn tich, o, th, phong thi nghim phai tin hanhcac hoat ng khc phuc ki p thi, phai thng bao bng vn ban cho cac c s co linquan bit v nhng sai sot nay hiu chinh chung.

d/ Lanh ao phong thi nghim phai inh ky, thng la 1 nm, xem xet lai h thng quan ly cht lng va cac hoat ng phn tich, o, th cua phong thi nghim

am bao s phu h p lin tuc va tinh hiu qua cua chung va a ra nhng thay ihoc cai tin cn thit.

Cac thutuc iu hanh

Cac chi dncng vic cu th

S taycht lng


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II. Cc phng php phn tch, o th.

Yu cu chung la PTN phai s dung cac phng phap va thu tuc phu h p vinhng yu cu a c xac inh trong cac chng trinh quan trc va phu h p vi cac

phep phn tich, o, th thuc pham vi hoat ng cua PTN, bao gm ca vic ly mu, xly, vn chuyn, lu kho va chun bi mu.

a/ Chon la phng phap

Tt nht la s dung cac phng phap a tiu chun hoa, o la cac tiu chun quct, tiu chun vung, tiu chun quc gia. Phai s dung nhng n phm mi nht cua cactiu chun. Khi cn thit, PTN phai hiu chinh cac tiu chun nay bng nhng chi tit bsung am bao s ap dung thich h p.

PTN cung co th chon cac phng phap thich h p a c cng b trong cac ta pchi, cac sach khoa hoc. Cac phng phap ni b (do PTN t xy dng) cung co thc s dung nu phu h p vi yu cu quy inh va phai c th hin thanh vn ban,c ph duyt theo thu tuc quy inh. i vi cac phng phap cha c tiu chunhoa nay cn phai co s thoa thun cua c quan quan ly chng trinh quan trc. S thoathun nay c th hin bng mt vn ban quy inh ro rang v cac yu cu va muc ichcua phep phn tich, o, th.

b/ Ph duyt phng phap

PTN phai kim tra lai cac phng phap tiu chun, khng tiu chun va cacphng phap mi khng inh cac phng phap nay la phu h p vi muc ich s dung.


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Hinh 1. Hoat ng QA/QC trong phong th nghim

Muc tiu cht lng

La chon phng phap

Xy dng phng phap

Bin soan phngphap

Chp nhn phng phap

- Kim tra hiu qua- anh gia hiu qua

Kim soat cht lng(bao gm bao tri thit bi)

Soat xet/chp nhn lai- Kim tra hiu qua- anh gia hiu qua

Tt Khng tt

Tt Khng tt


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Phai ghi lai cac kt qua cua vic ph duyt va thu tuc thc hin vic ph duyt nay.Vic ph duyt phai da trn cac thng s cua cac ky thut phn tich a c chon. Cacthng s va kt qua ph duyt phai c th hin bng vn ban va phai c lu tr.

S phu h p cua phng phap co th kim tra bng cach so sanh vi cac yu cuc trng cho vic s dung a inh nh khng am bao cua kt qua, gii han phathin, chon loc cua phng phap, tuyn tinh, gii han l p lai hoc tai l p,kha nng chng lai cac anh hng bn ngoai ...

Cac ky thut c s dung ph duyt mt phng phap co th la mt hoc mts trong cac cach sau: s dung cac chun o lng hoc mu chun; so sanh kt qua vicac phng phap khac; so sanh lin phong; anh gia mt cach h thng nhng yu tanh hng n kt qua; anh gia khng am bao cua kt qua da trn hiu bit khoahoc v cac nguyn tc ly thuyt cua phng phap va kinh nghim thc t.

c/ anh gia khng am bao

PTN phai co thu tuc anh gia khng am bao cua tt ca cac phep phn tich,o, th.

Phai quan tm n tt ca cac yu t gop phn vao khng am bao. Cac yu to la:

- Cac chun chinh, mu chun va trang thit bi s dung;- Phng phap phn tich, o th c la chon;

- iu kin mi trng;- c tinh cua i tng phn tich, o, th;- Ngi thao tac.Tai liu c ban anh gia, trinh bay khng am bao o hin nay la

ISO/TAG4/WG3 "Guide to expression of uncertainty in measurement", 1993 va b tiuchun ISO 5725: 1994: chinh xac ( chinh xac va chum) cua phng phap o vakt qua o (ISO 5725: 1994 Accuracy (truness and precsion) of measurement methodsand results).

III. Trang thit bi

a/ Trang thit bi cua phong thi nghim phai ap ng cac yu cu cua tiu chunhoc phng phap tng ng.

b/ Trang thit bi phai c anh du, dan nhan phn bit va nhn dang cd dang, trong o phan anh c tinh trang hiu chun, kim inh va thi han hiuchun, kim inh tip theo cua no.

Phai duy tri va lu gi h s cua tng loai trang thit bi .

c/ Phai thit l p cac thu tuc bao dng va thc hin vic bao dng trang thit bi thng xuyn hay inh ky.


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Trang thit bi sai hong phai c dan nhan phn bit vi cac trang thit bi binh thng. Phai ngng s dung no cho n khi sa cha, hiu chinh xong va vic hiuchun hoc kim inh sau o chng minh thit bi a hoat ng tt.

Khi vi ly do nao o, trang thit bi vt ra ngoai pham vi kim soat trc tip cuaPTN trong mt thi gian nht inh, PTN phai tin hanh kim tra am bao rng thit

bi vn u tt trc khi a vao hoat ng tr lai trong PTN.

d/ Phai am bao tinh lin kt chun o lng cua tt ca cac trang thit bi cuaphong thi nghim.

Thc cht cua yu cu am bao tinh lin kt chun chinh la vic thc hin mtchui phep hiu chun k tip nhau i vi tt ca trang thit bi cua PTN, lam cho cactrang thit bi nay u c so sanh (trc tip hay gian tip), va tip o la hiu chinh,

theo h thng chun o lng quc gia hay quc t, t o am bao cho trang thit bi o,th, phn tich lun tin cy va chinh xac. Cu th phong thi nghim phai thc hin mt svic sau:

+ PTN phai xy dng va thc hin chng trinh hiu chun cho tt ca cac trangthit bi co anh hng ro rt n gia tri va chinh xac cua cac kt qua phn tich, o, thtrc khi a chung vao s dung cung nh trong sut qua trinh s dung chung. Chngtrinh hiu chun phai bao gm ca cac phng tin o dung cho cac phep o phu tr, vidu o cac iu kin mi trng.

+ i vi nhng trang thit bi khng th thc hin c vic hiu chun nu trn,

PTN co th ap dung cac bin phap sau:- Tham gia mt chng trinh so sanh lin phong hoc thi nghim thanh thao co bng chng v s phu h p cua cac trang thit bi lin quan.

- S dung cac mu chun ma cac gia tri v thanh phn va tinh cht cua no ac chng nhn kim tra trang thit bi .

- S dung cac chun hoc cac phng phap a c cac bn lin quan thoa thun.

IV. Tin nghi v iu kin mi trng

a/ Yu cu chung la tin nghi cua PTN, bao gm ca cac iu kin v mi trng,chiu sang va cac ngun nng lng, phai phu h p co th d dang thc hin mt cachung n cac phep phn tich, o, th theo yu cu. Cn co s quan tm c bit khi vicly mu, hoc vic phn tich, o, th c thc hin nhng ni ngoai ia im cinh cua PTN. Phai quy inh thanh vn ban cac yu cu i vi cac tin nghi va iukin mi trng co th anh hng n kt qua phn tich, o, th.

b/ PTN phai co cac thu tuc va thc hin vic giam sat, kim tra chc chn rngmi trng khng tac ng xu ti vic ly mu; vic tin hanh phn tich, o, th. Victhc hin cac phep phn tich phai c dng lai khi cac iu kin mi trng khng phu

h p. Cn c bit kim soat s phu h p vi cac yu cu cua cac yu t nh s v trung


29/41

v mt sinh hoc, bui bn, nhng tin hiu in t gy nhiu, cht phong xa, vic cungng in, nhit , m, rung ng, ting n v.v...

c/ Trng h p co nhng hoat ng anh hng ln nhau, PTN phai phn l p mtcach co hiu qua nhng khu vc nay tranh nhng anh hng xu qua lai.

d/ PTN phai thc hin s kim soat i vi vic s dung va ra vao phong thinghim ma khng co nhim vu han ch nhng anh hng xu n kt qua phn tich,c bit la nhng ni co anh hng trc tip n cht lng cac phep phn tich.

V. Nhn s

a/ Ban lanh ao PTN phai am bao rng tt ca ky thut vin vn hanh trang thit bi co u trinh va nng lc cn thit. Trong PTN cac ky thut vin cn thng xuyn

c nng cao trinh ap ng yu cu thc t.b/ Nhim vu cua can b lanh ao va ky thut vin phai c phn cng ro rang vac th hin bng vn ban.

VI. Qun ly mu phn tch, o, th

a/ PTN phai co cac thu tuc thich h p cho vic quan ly mu i vi tng thng s.b/ PTN phai co cac cach nhn dang va phn bit mu. Nhng ky hiu nhn

dang phai c duy tri trong sut thi gian tn tai cua mu trong PTN am baokhng gy ra s nhm ln cac mu khi phn tich o, th khi lun chuyn, k ca khi a

vao h s, tai liu.c/ Khi tip nhn mu, PTN phai ghi lai moi s khng binh thng hoc sai lch

so vi s m ta trong cac phng phap phn tich, o, th ma PTN s dung; phai thamkhao y kin cua cac b phn lin quan ho cho cac hng dn cu th khi co s nghing v s phu h p cua mu.

d/ PTN phai co cac thu tuc va tin nghi phong tranh cac h hong i vi mutrong qua trinh lu gi, x ly, chun bi va tin hanh phn tich, o, th. Phai tun thu cachng dn kem theo mu.

VII. m bo cht lng cc kt qu phn tch

PTN phai am bao cht lng kt qua phn tich bng cach theo doi lin tuc cackt qua. Vic theo doi phai c l p thanh k hoach va co th bao gm cac cach sau:

Cac s kim tra cht lng ni b bng cach s dung ky thut thng k.

Tham gia cac chng trinh so sanh lin phong hoc th nghim thanh thao.

S dung u n cac mu chun a c chng nhn.

Tai tao lai cac phep phn tich bng cac phng phap ging hoc khac nhau.

Phn tich nghim lai cac mu c lu gi.


30/41

Xem xet s tng quan gia kt qua vi cac c trng khac nhau cua mu.

VIII. Kim sot cht lng trong phong th nghim

QC phong thi nghim chinh la mt chng trinh anh gia an xen vao cac hoat

ng tai hin trng va trong phong thi nghim anh gia chinh xac va ungn cua cac phep phn tich o th (goi vn tt la cac phep o).

Cac qua trinh QC c thc hin bng vic phn tich u n mu kim soat chtlng (mu QC) sau khi mt phng phap a c chng minh la thich h p cho vic sdung thng qua s ph duyt phng phap.

Cac mu QC c dung trong phn tich mi trng gm hai loai: mu QC phongthi nghim va mu QC hin trng.

Mu QC hin trng xem muc 1.4

1. Mu QC phong thi nghim

Mu QC phong thi nghim gm hai loai: mu QC phng phap va mu QC thitbi .

Mu QC thit bi

Cac mu QC thit bi dung anh gia va kim tra cht lng cua kt qua do thitbi mang lai. Mu QC thit bi bao gm: chun kim soat (control standard); chun thmtra (verification standard); mu trng thit bi (instrument blank).

Mu QC hin trng

Mu QC

Mu QC phong thi nghim

Mu QCphong thi nghim

Mu QC phng phapMu QC thit bi

Mu QC thit bi


31/41

+ Mu trng thit bi: mt mu nho dung mi, thng la nc ct, c cho trctip vao thit bi o s nhim do thit bi gy ra. Mu nay thng dung anh gia n inh va nhiu cua thit bi .

+ Chun kim soat: la chun dung kim tra chinh xac cua cac chun cdung chun hoa thit bi .

+ Chun thm tra: la chun theo doi n inh cua thit bi theo thi gian.

Mu QC phng phap:

Mu QC phng phap dung anh gia cht lng tt ca tinh nng s dung cuaphng phap trong phong thi nghim. Mu QC phng phap phong thi nghim gm:mu trng phng phap, mu l p phong thi nghim, mu thm phng phap, mu chunc chng nhn.

Mu trng phng phap: La mu bng vt liu sach c trai qua cac bc x lyging nh vi mu phn tich, o, th. Mu nay c dung anh gia s nhim tao

ra trong toan b mt thu tuc phn tich, o, th.

Mu l p phong thi nghim: Hai hoc nhiu hn cac phn cua cung mt mu t nhin c chun bi va phn tich ring re bng cung mt phng phap. Mu nay dung anh gia t p trung cua kt qua phn tich , o, th trong phong thi nghim.

Mu thm phng phap: Mu, vt liu sach hoc thuc th c cho thm vaomt lng a bit cua mt hay nhiu yu t phn tich va c x ly ging nh khi phntich, o, th. Mu thm anh gia mc sai lch gy ra do anh hng cua nn va sais cua phong thi nghim, cac sai s hiu chun, sai s chun bi muv.v...

Mu chun c chng nhn:

Mu QCphng phap

Mu chun cchng nhn

Mu l pphong thi ghim

Mu thmphng phap

Mu trngphng phap

Chun thm traMu trng thit bi Chun kim soat


32/41

Vic phn tich mu chun trong phong thi nghim trc ht la anh gia sai s, ung, sai s h thng cua phng phap c s dung.

2. Tiu chi chp nhn cua kim soat cht lng va bin phap khc phuc

Kim soat cht lng c thc hin thng qua vic phn tich, o hoc thnghim mt s loai mu QC a nu trn nhn dang cac ngun sai s xac inh. Tuynhin kt qua phn tich, o, th cac mu QC se chi co y nghia khi a ra c cac giihan so sanh vi chung. Vi du khi phn tich mu trng hin trng, mu trng vnchuyn, mu trng thit bi ... cn co cac gia tri inh mc thich h p bit mc nhim gy ra trong qua trinh ly mu, vn chuyn mu, hoc do thit bi gy ra con chpnhn c hay ti mc nguy him, cn truy tim nguyn nhn loai bo no. Hoc khihiu chun thit bi bng cach so sanh vi chun, se xac inh c sai s s chi cua thit

bi nay. Nhng cung vi no phai bit sai s cho phep ln nht cua thit bi la bao nhiu quyt inh xem co cn hiu chinh a sai s v pham vi cho phep hay khng v.v...

Mt vi du in hinh la s dung cac "gii han canh bao" va "gii han kim soat".Nh khi phn tich"mu l p phong thi nghim", ta xac inh c lch chun s ctrng cho s phn tan ( t p trung) cua phng phap (thu tuc) phn tich c s dung.Gii han canh bao c ly la 2s va gii han kim soat c ly la 3s. Gia tri 2s va 3sgoi la gii han canh bao va gii han kim soat trn (ky hiu la UWL va UCL). Gia tri -2s va -3s goi la gii han canh bao va gii han kim soat di (ky hiu la LWL va LCL).Khi s thanh thao cua PTN tng ln, gia tri cua cac gii han nay se nho xung. Cac gii

han 2s va 3s ng vi mc tin cy 95,45% va 99,73%. iu nay co nghia la vi 100phep phn tich ta hy vong nhiu nht la chi co 5 phep phn tich co gia tri vt qua giihan canh bao va c 300 phep phn tich hy vong chi co 1 gia tri vt qua gii han kimsoat. Vi mt gia tri nn xac inh ta co biu kim soat sau y:

Khi gia tri thu c vt ra khoi gii han canh bao, nghia la bt u co nhngvn phai quan tm xem xet va khi gia tri thu c vt qua gii han kim soat, conghia la vn a tr nn nghim trong va nguy him. Cac bin phap khc phuc phai

c ra va thc hin. Bang di y cho mt vi du v cac hanh ng khc phuc trongmt tinh hung cu th.

UCL3s

UWL2s

Nn

LWL-2s

LCL-3s


33/41

K hoach khc phuc cc sai sot cua QC

A. Cc gi thit:

1. Trung binh co 1 trong 20 im o vt qua gii han canh bao (WL) 2 lchchun (2SD) va 1 trong 300 im o vt qua gii han kim soat (CL) 3 lchchun (3SD).

2. ng trung tm la x ln gii han phat hin cua phng phap (MDL) vi x itnht la 20 ln MDL.

3. Tiu chun va cac hanh ng x ly ap dung cho cac im o nm trn va digii han cua tham s va khng ap dung nu cac im o nm trn hai cn cuatham s.

B. Bin php khc phuc

Tham s thng k Tiu chun Hanh ngGii han kim soat(CL) la 3SD (3s)

1. Mt im o vt qua CL2.a. Cac phep phn tich l p lai < CL2.b. Cac phep phn tich l p lai > CL

1. L p lai phep phn tich2.a. Tip tuc phn tich2. b. Dng lai va hiu chinh

Gii han canh bao(WL) la 2SD (2s)

1. 2 hoc 3 im o > WL2.a. im o tip theo < WL 2. b.im o tip theo > WL

1. Phn tich mu khac2. a. Tip tuc phn tich2. b. Dng laiva hiu chinh

lch chun (SD) 1. 4 hoc 5 im o > 1 SD2.a. im o tip theo < 1SD

2.b. im o tip theo > 1SD

1. Phn tich mu khac2. a. Tip tuc phn tich2.b.Dng lai va hiu chinh

ng trung tm(CTL)

1. im o trn CTL2.a. im o tip theo di CTL2.b. im o tip theo trn CTL

1. Phn tich mu khac2. a. Tip tuc phn tich2. b. Dng lai va hiu chinh

C. Sau khi tin hnh cc hoat ng khc phuc

Phn tich lai mt na s mu nm gia im cui cung trong gii han kim soatva im ngoai cung ngoai gii han kim soat.

IX. So snh lin phong th nghim v th nghim thnh thao

Mt trong cac bin phap kim soat cht lng PTN co hiu qua la vic t chc vatham gia so sanh lin PTN va th nghim thanh thao.

So snh lin phong th nghim (Interlaboratory compairison)La vic t chc va thc hin anh gia cac phep phn tich i vi cac mu hoc vt

liu th hoan toan ging nhau hoc tng t nhau bi hai hay nhiu PTN theo s thoathun vi nhng iu kin c xac inh.


34/41

So sanh lin PTN nhm cac muc ich: xac inh nng lc cua PTN i vi cac phepphn tich, o, th nghim; kim tra s tng thich va nht quan cua s liu i vi tngca nhn ky thut vin cua PTN; thit l p cac phng phap phn tich; o, th mi; giaiquyt s khac nhau gia cac PTN; xac inh gia tri cac mu chun c chng nhnv.v...

Th nghim thnh thao (proficiency testing)

La vic xac inh cht lng thc hin vic phn tich bng cach so sanh lin PTN.

Muc ich cua vic th nghim thanh thao chinh la nhm xac inh nng lc cuaPTN i vi cac phep phn tich do cac PTN cng b.

Th nghim thanh thao c thc hin bng chng trinh th nghim lin PTN.

Chng trinh th nghim lin PTN (interlaboratory testing programmes)

La vic so sanh lin PTN trong o cac mu cua mt vt liu th ng nht cphn phat thc hin cac phep phn tich thich h p tai cac PTN tham gia.


35/41

Phu luc 2. X ly s liu theo phn b chun

(phn b Gauss)

1. lch chun cua phng php a bit

Kt qua cua phep o 1 ln c trinh bay nh sau:Q= X ts; vi P = 95%Trong o: Q la gia tri thc cua ai lng;

X la gia tri thu c t phep o 1 ln, c coi la kt qua o (la gia tri cua ai lng o);

P la xac sut (mc tin cy);t la h s phu thuc P (bang 1 va bang 2 cua phu luc).

iu trn co nghia la vi xac sut tin cy P a chon, sai s cua kt qua o (X)nm trong gii han ts, cung co nghia la gia tri thc Q cua ai lng se nm trong

khoang t X - ts n X + ts. Trng h p P c ly bng 95% (0,95), khi o h s t = 2,co nghia la nu ta tin hanh 100 phep o theo phng phap y se hy vong chi co 5 lno co sai s vt ra ngoai gii han 2s. Chon P bng bao nhiu la tuy thuc vao yucu cu th.

V du: Sai s cua phep o mt ln co th bng bao nhiu nu phng phap o acho co s =0,01 n vi va c 100 ln o thi trung binh co 5 ln sai s vt qua gii hanquy inh. Bai toan nay cung co nghia la tim gii han sai s cua phep o vi s =0,01 vva P = 95%.

Bang 2 Phu luc I phn b chun cho ng vi P=95%, ta co t=2. Sai s cua phepo 1 ln trong trng h p nay la:

ts = 2 x 0.01v = 0,02 v

2. Trng hp cha bit lch chun s cua phng php

Thc hin n ln o (th, phn tich) lin tip cung mt ai lng. Tinh gia tri trung binh cng ( x ) va lch chun thc nghim nh sau:

xn

x

n

nxxx

n

i

i==

++= 1

21...

trong o: x1, x2 ....xn la gia tri thu c tng ln o;

n la s ln o l p lai.

=s ( )

1

1

2

=

n

xx

n

i

i

Gia tri trung binh x c ly lam kt qua o. lch chun s c trng cho s phn tan cua cac gia tri o ring re x i xung quanh gia tri trung binh x. Gia tri s ln conghia la cac gia tri o ring re x i phn tan nhiu quanh x, tc phep o co t p trungthp va ngc lai.

Kt qua cua phep o c trinh bay nh sau:


36/41

Q = x sn

ts

Vi P = ....

Trong o: Q la gia tri thc cua ai lng; x la gia tri trung binh;

ts la h s phu thuc s ln o l p n va xac sut tin cy P a chon c tratheo bang 1 va bng 2 phn b Student (phu luc)

s la lch chun thc nghim;P la xac sut tin cy.

iu trn co nghia la vi xac sut tin cy P a chon sai s cua kt qua o ( x)

nm trong gii han

s

n

ts , co nghi a la gia tri th c cua ai lng se nm t

sn

tx

s n

+ sn

tx

s .

V du: xac inh chinh xac khi lng mt mu th, ta cn lin tip 6 ln muo, c cac kt qua sau (n vi g):

72,631 72,34472,357 72,34673,352 72,340

Khi lng thc cua mu bng bao nhiu vi xac xut tin cy la 99%.

Tinh: x=6

ix = 72,350 g

=s ( )16

350,721

2

=n

i

ix

8,06 x 10-3g

Tra bang 1 phu luc I, ng vi n = 6 va P = 99%, co ts = 4,03. Ta co:

sn

ts = gxgxx

3310131086,0

6

03,4

Kt qua o cui cung c th hin la:m =(72,350 0,013)g, vi P = 99%

3. Lm tron sKhi lam tron tri s cua kt qua o, ngi ta cn c vao bc co nghia cua sai s. Tri

s cua kt qua o phai tn cung bng con s cung bc vi tri s cua sai s. Vi du, khi sais la 5, con s tn cung se la con s ng vi hang n vi, khi sai s la 0,02, con stn cung se la s le phn trm...

lam tron s, ap dung cac quy tc sau y:a. Nu k tip con s cui cung cn lai khi quy tron la cac con s nho hn 5 thi

khi quy tron, con s cui cung se khng thay i (quy tron xung hay giam).Vi du:

2,12 2,1

6,343 6,34


37/41

b. Nu k tip con s cui cung cn lai khi quy tron la cac con s ln hn 5 thikhi quy tron, con s cui cung se tng thm 1 (quy tron ln hay quy tron tng).

Vi du: 3,14159 3,14168,248 8,25

c. Nu k tip con s cui cung cn lai khi quy tron la con s 5 va sau con s 5co it nht mt con s khac khng thi khi quy tron con s cui cung o se tng thm 1(quy tron tng).

Vi du:4,3501 4,4

d. Nu k tip con s cui cung cn lai khi quy tron la con s 5 va bit ro con s5 nay a c quy tron nh th nao thi con s 5 o se c quy tron xung theo quy tca nu nh no a c quy tron ln va se c quy tron ln theo quy tc b nu nh no ac quy tron xung.

Vi du: 6,3149 a c quy tron thanh 6,315 nu tip tuc se c quy tron thanh

6,31. 4,1852 a quy tron thanh 4,185, nu tip tuc se quy thanh 4,19.e. Nu k tip con s cui cung cn lai khi quy tron la con s ung 5 (sau no chi

toan la s 0) thi co th tuy y quy tron ln hay quy tron xung. Nhng nu cn s dung squy tron trong khi tinh toan thi nn quy tron nh th nao con s cui cung la con schn. Nh vy, con s cui cung o se khng thay i nu no a la con s chn va setng thm 1 nu no la con s le (quy tc s chn).

Vi du:

06200625016

1,, =

807504

3,, =

f. Nu k tip con s cui cung cn lai khi quy tron la con s 5 nhng khngbit no la con s ung 5 hay a c quy tron, thi xem con s 5 o la con s ung vaquy tron theo quy tc e.

4. Loai bo kt qu o bt thng

Kt qua cua mt ln o ring re trong day n phep o cung mt ai lng c coila bt thng nu no lch mt cach ang k so vi nhng gia tri con lai. Bang phn bchun va phn b Student cho thy xac sut a = 1 - P mt kt qua o ring re lch so

vi gia tri trung binh 3s hoc 4s la rt nho ( a ng vi xi - x > 3s la 0,3% va ng vixi - x > 4s la 0,01% ). Vy co kt qua nao lch vi xqua gii han 3s hoc 4s (tuytheo P c chon) co th coi la mc sai s th va loai bo chung trong qua trinh x ly ktqua o.


38/41

Bang 1

Gi tri tch phn xc sut dte)t(t t

=

0

2

2

2

2theo cc gi tri t cho trc

t F(t) t F(t) t F(t) t F(t)

0,00

0,05

0,10

0,15

0,20

0,250,30

0,35

0,40

0,45

0,55

0,60

0,55

0,65

0,60

0,75

0,80

0,85

0,90

0,0000

0,0399

0,0797

0,1192

0,1585

0,19740,2358

0,2737

0,3108

0,3473

0,3829

0,4177

0,4515

0,4843

0,5161

0,5467

0,5763

0,6047

0,6319

0,95

1,00

1,05

1,10

1,15

1,201,25

1,30

1,35

1,40

1,45

1,50

1,55

1,60

1,65

1,70

1,75

1,80

0,6579

0,6827

0,7063

0,7287

0,7499

0,76990,7887

0,8064

0,8230

0,8385

0,8529

0,8664

0,8798

0,8904

0,9011

0,9109

0,9199

0.9281

1,85

1,90

1,95

2,00

2,05

2,102,15

2,20

2,25

2,30

2,35

2,40

2,45

2,50

2,55

2,60

2,65

2,70

0,9357

0,9426

0,9488

0,9545

0,9596

0,96430,9684

0,9722

0,9756

0,9786

0,9812

0,9836

0,9857

0,9876

0,9892

0,9907

0,9920

0,9931

2,75

2,80

2,85

2,90

2,95

3,03,1

3,2

3,3

3,4

3,5

3,6

3,7

3,8

3,9

4,0

4,,5

5,0

0,9940

0,9949

0,9956

0,9963

0,9968

0,997300,99806

0,99862

0,99904

0,99932

0,99954

0,99968

0,99978

0,99986

0,99990

0,999936

0,999994

0,9999994


39/41

Bang 2Gi tri t theo gi tri tch phn xc sut cho trc

F(t) 1- F(t) t F(t) 1- F(t) t0,50

0,60

0,70

0,75

0,80

0,85

0,90

0,950,96

0,97

0,98

0,99

0,991

0,50

0,40

0,30

0,25

0,20

0,15

0,10

0,050,04

0,03

0,02

0,01

0,009

0,675

0,842

1,036

1,150

1,282

1,440

1,645

2,9602,054

2,170

2,326

2,576

2,612

0,992

0,993

0,994

0,995

0,996

0,997

0,998

0,9990,9995

0,9999

0,99999

0,999999

0,9999999

0,008

0,007

0,006

0,005

0,004

0,003

0,002

0,0015.10-4

1.10-4

1.10-5

1.10-6

1.10-6

2,652

2,697

2,748

2,807

2,878

2,968

3,090

3,2193,481

3,891

4,417

4,892

5,327


40/41

Bang 3.

Gi tri ts ng vi xc sut tin cy Ps v s ln o n khc nhau

Ps

n0,5 0,6 0,7 0,8 0,9 0,95 0,98 0,99 0,999

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

1,000

0,816

0,765

0,741

0,727

0,718

0,711

0,706

0,703

0,700

0,697

0,665

0,694

0,692

0,691

0,690

0,689

0,688

0,688

0,674

1,376

1,061

0,978

0,941

0,920

0,906

0,896

0,889

0,883

0,879

0,976

0,873

0,870

0,868

0,866

0,865

0,863

0,862

0,861

0,842

1,963

1,336

1,250

1,190

1,156

1,134

1,119

1,108

1,110

1,093

1,088

1,083

1,079

1,076

1,074

1,071

1,069

1,067

1,066

1,036

3,08

1,886

1,638

1,533

1,476

1,440

1,415

1,397

1,383

1,372

1,363

1,356

1,350

1,345

1,341

1,337

1,333

1,330

1,328

2,282

6,31

2,92

2,35

2,13

2,02

1,943

1,895

1,860

1,833

1,812

1,796

1,782

1,771

1,761

1,753

1,746

1,740

1,734

1,729

1,645

12,71

4,30

3,18

2,77

2,57

2,45

2,36

2,31

2,26

2,23

2,20

2,18

2,16

2,14

2,13

2,12

2,11

2,10

2,09

1,960

31,8

6,96

4,54

3,75

3,36

3,14

3,00

2,90

2,82

2,76

2,72

2,68

2,65

2,62

2,60

2,58

2,57

2,55

2,54

2,33

63,7

6,92

5,84

4,60

4,03

3,71

3,50

3,36

3,25

3,17

3,11

3,05

3,01

2,98

2,95

2,92

2,90

2,88

2,86

2,58

636,6

31,6

12,9

8,61

6,86

5,96

5,40

5,04

4,78

4,59

4,49

4,32

4,22

4,14

4,07

4,02

3,96

3,92

3,88

3,29


41/41

Bang 4

Gi tri xc sut tin cy Ps tng ng vi cc gi tri ts v n khc nhau

tsn 2 2,5 3 3,5

2

3

4

5

6

7

8

9

10

11

12

13

14

1516

17

18

19

20

0,705

0,816

0,861

0,884

0,898

0,908

0,914

0,919

0,923

0,927

0,929

0,931

0,933

0,9350,936

0,937

0,938

0,939

0,940

0,955

0,758

0,870

0,912

0,933

0,946

0,953

0,959

0,963

0,966

0,969

0,970

0,972

0,974

0,9740,975

0,976

0,977

0,978

0,976

0,988

0,795

0,905

0,942

0,960

0,970

0,976

0,980

0,983

0,985

0,987

0,988

0,989

0,990

0,9900,991

0,992

0,992

0,992

0,993

0,997

0,823

0,928

0,961

0,975

0,983

0,987

0,990

0,992

0,993

0,994

0,995

0,996

0,996

0,9960,997

0,997

0,997

0,998

0,998

0,9995

giáo trình quan trắc mt

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