Tuyin tap bao cdo khoa hgc Hgi nghi Khoa hgc ky thuat Do ludng toan qudc Idn thfi IV Hd Ngi, 11 - 2005
, HIEU CHUAN VA KIEM DjNH HAI HOAT DONG KHAC NHAU VE NGUYEN TAC N H U N G CUNG CHUNG N H Q N G THU TUC DO
Nguyin Tiin Luang Hgi Do ludng Viet Nam
Abstract:
CaUbration of the measuring instruments according to the implemented quality system. Verification of the measuring instruments according to legal regulations. Both actions have been established with separate rules, metrogical infrastructures and activities, but are strongly inter-related and based on the same measuring procedures ensuring the correct indications of measuring instruments. This paper makes clear the differences, common bases and the relationship beetween calibration and verification and suggests using the results of verification into calibration purpose
Kilm dinh (KD) nhdm duy tri su dfing ddn cua phuong tien do (ptd) dugc sfi dung vao nhung muc dich quy dinh. Ndi each khdc, KD Id boat ddng dam bao cho su dfing ddn cua ptd ttong do ludng phap quyin.
Cung vdi muc tieu nay - de duy tri su dung ddn cua ptd, nhung hieu chudn (HC) lai dp dung vdi ddi tugng la nhiing ptd khdc, dd la ptd dung trong cdng nghiep. HC cung cdp bdng chthig la ptd da dugc lien kit chudn tdi he don vi SI (dam bao su thdng nhdt do ludng), ddng thdi cho biet "su tin tudng" - chinh xac hon la "dd khdng dam bao do" (DKDBD) cua ptd. Mdt td chfic mudn xdy dung he thdng quan ly chdt lugng (HTQLCL) iheo mdt chudn muc ndo dd, tbi du ISO 9000, hoac ISO/IEC 17025 v.v... thi nhfing ptd sfi dung cdn phai dugc HC.
Nhu vdy, KD vd HC vdi cung mdt muc tieu la dam bao su dfing ddn cua ptd, nhung dp dung cho hai ITnh vuc do ludng khdc nhau dd la do ludng phap quyin (DLPQ) va do ludng cdng nghiep (DLCN). Trong thuc te, cd mdt sd khdng ft ptd cdn sfi dung vao ca hai muc dich neu tren. Vi vdy, viec lim hiiu ddy dii nhiJng md'i lien he chung, cung nhu nhfing dac dilm rieng cua hai loai boat ddng nay la diiu cdn thiet.
Bai vil^t nay, dua tren nhiing tu lieu qudc te (xem tai lieu tham khao) vd ddi chilu vdi thuc tiln hoai ddng do ludng nude ta, tham vgng lam sang td mdi quan he gifia HC vd KD ca vl hai phuong dien ky thudt va phdp ly do ludng, tfi ddy kieh nghi bien phap giam thilu nhihig thu luc ky thudt (technical procedures) khi sfi dung ptd da dugc KD vao viec xdy dung HTQLCL cua doanh nghiep. Sau day ta xem xet tfi cdc gdc dd khdc nhau:
I. XUAT PHAT TLTDINH N G H I A KD VA HC Hieu chuan la gi ?
Theo VIM [1]: HC la ldp hgp cac thao tac dl thilt Idp, trong nhfing diiu kien xac dinh md'i lien he gifia gia tri ciia dai lugng dugc chi thi bdi ptd... va gia tri tuong fing thi hien bdng chudn.
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HC khfing nhdt thiet phai hifiu chinh; HC chi cdn cho hiit "dfi lech" do luofng hoac
"sfi hieu chi'nh" va DKDBD. DKDBD la thfing sfi gdn vfii ket qua do, dac uung cho dfl phan tdn cia cdc gia tri cfi thi quy cho dai lupng do mflt each hpp ly. Nfii dPn gian hon.
DKDBD la "thufic do" cia su "khfing hoan thien" vi gid tri cia dai lupng do. Nhu vdy, HC Id hoat dfing ky thudt do lu&ng nham xac dinh thufic tinh do lu&ng cia ptd, nfi khfing mang ti'nh phap ly quan ly.
Kiem dinh la gi?
Kiim dinh la tap hpp nhttng thao tac thuc hien b6i co quan cfi thdm quyin vi do lufifng di khang dinh phuong tien do da hoan todn thoa man nhung yfiu cdu quy dinh.
Kiim dinh bao gfim nhttng thao tac ky thuat de xac dinh tinh nang do lufing cia ptd da thoa man nhflng yfiu cdu quy dinh hay chua; dfing th&i ca hanh dfing phap ly nhdm
"chimg nhan ptd" da dat dupe mflc yfiu edu - thi hien hfii sai sfi cho phep cua ptd.
II. LICH SiTRA DC3l CUA KIEM DINH VA HIEU C H U A N KHAC NHAU KD ra dfifi cung vfifi su hinh thdnh va phdt triin cia do luftng phdp quyin (DLPQ). Su mau thudn vi quyin lpi cia ngufti mua va ban bdt ddu tfl viec "cdn do" trong Uao dfii, bufln bdn. Xa hfii phdt triin, su mau thudn ndy mfi rfing sang cdc ITnh vuc an toan, sflc khoe, mfli tru&ng; va khfing con chi trong pham vi mfit nufic, mfit khu vuc md trfin pham vi todn the gifii. Su thfi'ng nha't do lufing trufic hit la thfi'ng nhdt vi dpn vi do va cufi'i ciing Id kit qua do: sfi ehl cia ptd phai gdn vfifi gia trj thuc cua dfi'i tupng do. Mfit bien phdp khfing thi ndo khac Id lam cho cdc ptd ciing loai phai dat din mfit dfi chinh xac nhdt dinh dfi la KD. Nha nufic, vfii tu cdch la ngufii quan ly xa hfii, phai cham lo xay dflng he thfing KD vi muc dfch efing bang xa hfii.
Trong khi dfi, cdc ptd dung trong cfing nghiep, tuy theo yeu cdu cfing nghe, yeu cdu vi chdt lupng san phdm md ptd cdn duy tri dfi chi'nh xdc din ddu. Yeu cdu nay do chinh ngufii sfl dung ptd quyit dinh, thfing qua viec HC nfi. Nhu vay, viec HC ptd phai do chinh ngu&i sfl dung ptd quyit dinh. Tuy nhien, di thfing nhdt do lufifng, thuc ddy su phdt triin cia xa hfii, Nha nufic phai hufing ddn, giflp dfi di xay dung he thfing HC ptd. Vfifi cdc nufic cfing nghiep phat triin, he thfing HC ptd dupe xdy dung khd hodn chinh, thi du he thfing DKD cua CHLB Dflc. Nufic ta, nen efing nghiep chua phat triin, chung ta chua cfi " he thfi'ng HC". Khdi niem HC mfii dupe si dung 5-10 nam lai ddy va cfin su nhdm Idn gitta KD va HC. Gdn day, cung vfifi phong trao xdy dung HTQLCL, nhu cdu HC ptd mfii dupe de cap din va ting bufie phan biet nfi vfii KD, lam ro thuc chdt cia hoat dfing nay.
III. MOI QUAN HE GIUA SAI SO CHO PHEP VA D 6 KHONG DAM BAO DO TRONG KIEM DINH
Sai sfi cho phep, hay gpi day di la sai sfi cho phep Ififn nhdt, viit tat bdng tiing Anh la MPE, la chfi dua khfing thi thiiu cia mpi Quy tnnh kiim dinh ptd. "Cho phip" 6 ddy la
"phdp ludt cho phep" hay nfii khdc di la phdp luat quy dinh. Cdn phai nhdn manh rdng, khfing cfi sai sfi cho phep chung chung cho mpi trufing hpp, md phai la sai so cho phep cu thi cho tflng uuang hpp eua ptd. Da biit sai sfi cia phep do bao gfim sai so cia ptd, vd sai sfi eho phep cua ptd trong kiim dinh khac vfii sai so cho phep cua ptd trong si dung. Thfing thu&ng, dfii vfii hdu hit eac ptd, ngufti ta quy dinh sai sdcho phip Irong sii dung, ky hieu id MPE 5 (bao gdm ca Irong thanh lra,kiim Ira pid Irong qud Irinh sic dung) bdng 2 Idn sai sd cho phip trong kiem dinh ptd, ky hiiu Id MPE^, [2], [3]
MPEs = 2 . MPE,
Thf du sai sfi cho phip khi kiim dinh MPEv cia cfit bom nhien lieu la 0,5%, thi sai sfi cho phip trong si dung MPE s (bao gfim thanh tra, kiim tra) la 1%
Tfi nhung diln giai tren, ta hay phdn biet mdt each idng qudt hai hoat ddng KD va HC nhu sau:
Hieu chuan
- Xdc dinh mdi quan he giua gia tri do va nhfing gia tri lucmg fing the hien bang chudn dudi dieu kien xac dinh vd thdi dilm nhdt dinh.
- C6ng bd do lech hoac sd hieu chi'nh va DKDBD.
- cap chfing chi hieu chudn theo ytu cdu ciia khdch hdng
Kiem dinh
- Xem xet vl su phii hop cua phucmg tien do so vdi ySu cdu phdp ly.
+ Cac phep thfi danh gia chdt luong + Sai s6 cho phep l i ^ nhdt (MPEO - Dong ddu, dan tem (chfic nang quan 1;^).
- Cdp gidy chfing nhan kilm dinh theo quy dinh
IV. DO KHONG DAM BAO DO TOONG KIEM BWH
Trong cac Quy trinh kiim dinh thu&ng khfing di cdp din DKDBD, nen trong Gidy chflng nhdn kiim dinh khfing tnnh bay ro rang vi DKDBD. Thue ra thfing qua cac quy dinh vi chpn chudn di KD va quy dinh vi diiu kien KD nhu mfii trufing KD vfii nhiet dfi, dfi dm, dp sudt khi quyin, til tru&ng, dien tru&ng...nam trong mfit gifii han ndo dfi da dn chiia mflt gid tri vi DKDBD. DKDBD dfi thufing dupe coi la di nhfi neu nfi khflng vupt qud 1/3 sai sfi cho phep khi KD [2],[3].
U(k=2) < 1/3 xMPEv.
Trong dfi U Id DKDBD vfii k Id he sfi phi
Hinhl. [2]: Sai so cho phep va DKDBD (k=2)
Hinh ve diin ta cac kit qua do cfi ciing mpt DKDBD Id U = ± 1/3 MPEy. Cdc kit qua do y,, yi, ys vd y. Id dat yfiu cdu KD; vi gid tri sai sfi thu dupe nam trong gifii han sai sfi cho phip khi KD MPEv. Cfin cac kit qua do y^ vi y^ la khfing dat yfiu cdu KD vi Ifin hon sai sfi cho phep khi KD MPEv.
Trong qud trinh su dung phuong tien do, sfi chi cia phuong tien do si bj "trdi di"
ldm cho sai sfi co xu hufing tdng len vd DKDBD cung se tdng Ifin theo th&i gian. Din lie ndo dfi, sai sfi se tang Mn vflpt qua gid tri MPEj. Chi'nh vi vdy, viec quy dinh chu ky KD thfch hop de kip thfii hieu chinh sai sfi cia phucmg tien do nho lai la diiu cdn thiit. Hinh 2 cho thd'y qua trinh trfli cia sfi chi cua phuong tien do theo thfii gian sfl dung. Kit qua Id gia tri sai sfi va DKDBD diu tang Ifin
Hinh 2. Su tang sai so' va tang dp khong dam bao do theo thfii gian
Tfl nhflng phan tfch tren, ta cfi thi so sanh mfit cdch todn difin phdn biet gifla KD vd HC nhu sau, [3]:
Chi tieu so sdnh 1. Can cfi de so sanh
2. Muc dich, pham
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3. Diiu kien tien quylt 4. Hieu luc ciia ket qua
5. Ddnh gid ke't qua 6. Lien ket chudn 7, DKDBD
Kiem dinh - Yeu cdu phdp ly (quy trinh KD) - Dam bao sd chi ndm trong sai sd cho phep MPEs trong sudt chu kj sfi dung ptd.
- Sfi dung ttong pham vi quy dinh (phap ly)
- Chdp nhan duoc KD true tie'p hoac qua phe duyet mdu
- Trong chu ky KD da quy dinh - Td chiic CO thdm quyen - Theo quy dinh - U < 1/3MPEV
Hieu chuan - Quy dinh ky thuat, tieu chudn, yeu cdu cua khdch hang
- Quan he gifia sd chi va gia tri thuc quy udc
- Thfia nhan rdng rai kei qua hieu chudn
- Phuong tien do HC duoc - Tai thdi dilm HC vdi dieu kien cu thi
- Ngudi sfi dung ptd danh gia - Ph6ng HC cung cdp bang chfing - Phu thu6c vdo kha nang ky thuat ciia PTN vd linh nang ciia ptd
Nhu vdy, thitc hien mfit each nghiem tflc mfit Quy tnnh KD ptd la da cfi thi dam bao:
- Tfnh lien kit chudn;
- Cfi can cfl d i ti'nh dupe DKDBD.
Mat khac nhu ta dd biit, vi mat ky thuat do lufing, hai hoat dpng KD va HC diu dua tren nhttng thu tuc do nhu nhau: Cac phip kiim tra, cac phip thfl. Thf du du la KD hay HC mflt cdi cdn cung diu phai thuc hien cdc phep thfl nghiem v i do lufing nhu dfi nhay (hoac dfi dfing), dfi lap lai, dfi lech tdm, dp diing, va nhflng chi tieu do lu6ng khdc tujf theo chung loai edn nhu dfi bfi, dp trfi, dp hfii sai,...
Nhflng thuc t i la cdc chuyfin gia danh gid HTQLCL thuftng khfing chdp nhdn kit qua KD. Vi sao?
Bdi vi, gidy chflng nhdn KD thu&ng khfing cho sfi lieu do cu t h i va khfing ehi ro DKDBD. Vi vay, mufin sfl dung dupe kit qua KD ma khfing phai thuc hifin HC lai ptd dfi thi phai "tai heu hod" ket qua KD mfit cdch day d i (thfing qua Gidy chflng nhan KD hoac Bifin ban KD), cung cdp d i bang chflng v i DKDBD.
So dfi dufii day cho ta bfle tranh toan canh v i qud trinh KD vd qud tnnh HC ptd su dung vdo hai hnh vuc do khdc nhau la Do lufing phdp quyin vd Do lufing cfing nghiep Mufin sfl dung ket qua KD ptd vao ITnh vuc HC (ptd dfing thfii duoc s i dung vao do lufing cfing nghiep de xdy dung HTQLCL...) thi cdn bfi sung bang chflng v i DKDBD
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HC
Cac phep thfi so sdnh vdi ytu cdu sfi dung
Sua chfia hoac ha cdp
Chfing nhan HC
KD
^r Cac phep thfi so sanh vdi
yeu cdu phap ly
• " '
Chfingnhan KD &
dan tem
1
Sfia chfia
'
loai bo
PTD dting Irong
DL cdng nghiep Bdng chiing DKDBD
PTD diing trong DL phdp quyin
V. MOT VAI KET LUAN
- KD va HC ptd la hai boat ddng cd tfnh chdt quylt dinh d i n viec dam bao cho ptd duy tri duge tinh lien ke't chudn va dd ehinh xdc cua ptd trong hai ITnh viic do la Do ludng phap quyin vd Do ludng cdng nghiep. Hai boat ddng nay khdc biet v l mat phap ly va muc tieu phuc vu, nhung diu dua tren nhung thu tuc do (phep thfi, phep kilm tra) tuong tu .
- D l sfi dung dugc kit qua KD vao muc dich dam bao do ludng trong xdy dung he thdng QLCL, cdn bd sung vao hd so KD vl sd lieu KD va chi ro DKDBD.
Tdi lieu tham khdo:
1. International Vocabulary of Terms in Legal Metrology, OIML. 2000
2. Wilfried Schulz, Klaus-Dieter Sommer: Uncertainty of measurement and error limits in Legal metrology.
3. Klaus-Dieter Sommer, (LMET) Germany, Samuel E. chappell (NIST), USA;
Manfred Kocester (PTB), Germany: Calibration and verification: Two procedures having comparable objectives and results.
4. Dai Runsheng, Han Jianping: The relationship between calibration, verification and metrological comfirmmation.
5. Nguyin Tii'n Luang: Sai sd cho phip trong Do ludng Phdp quyen
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