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5/18/2015
1
5/18/2015
CHO MNG CC BN N VI MN
HIU CHUN THIT B O LNG
KHOA IN - T NG HA
TRNG CAO NG NGH DU KH
5/18/2015
GII THIU
CONTROLLER
PROCESS
FINAL CONTROL ELEMENTS
MEASURING MEANS
5/18/2015
TM QUAN TRNG CA VIC HC/HC
HC, HC l so snh cc gi tr ca thit b ovi thit b chun bit nh gi sai s, cc c trng k thut o lng v c thchnh li
Vn hnh thnh cng mt qu trnh phthuc vo chnh xc v c tnh ca tngthit b o trong mch iu khin
HC, HC thit b gip cho qu trnh cngngh vn hnh an ton trong phm vi kthut cho php
5/18/2015
TM QUAN TRNG CA VIC HC/HC
HC, HC cn thit khi thay i cc thng s ca qu trnh cng ngh hay thit b.
Hiu chun, hiu chnh l t nguyn. Mt h thng o lng, iu khin m
bo tin cy khi tng phn t trong h thng phi tin cy.
5/18/2015
HC, HC li c thc hin trong mt s trng hp sau:
l Sau mt thi gian vn hnhl Thit b mi trc khi a vo lp
tl Thit b sau khi sa chal Khi thay i v tr lp t thit b ol
TM QUAN TRNG CA VIC HC, HC
5/18/2015
Mt thit b c HC, HC hon ho th ctnh ca n nm trong m t k thut canh ch to
Tng thit b o trong mch iu khinc HC, HC hon ho m bo cho hthng hot ng chnh xc v an ton
S vn hnh ca tng thit b o trongmch iu khin nh hng ti tt c ccthit b o khc trong cng h thng
S CN THIT PHI HC, HC TNG THIT B O
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2
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PHM VI O V SPAN
Phm vi o: Tp hp cc gi tr ca i lng o m sai s ca PT c xem l nm trong gii hn quy nh
Span l s chnh lch gia gi tr gii hn trn v gi tr gii hn di ca thang o ng dng.
5/18/2015
PHM VI O V SPAN
V d: Mt transmitter nhn gi tr vo t 0 50 psi, tn hiu ra ca n l 4 20 mA. Ta c:
l Phm vi o tn hiu vo: 0 50 psil Phm vi o tn hiu ra: 4 20 mAl Span tn hiu vo: 50 psil Span tn hiu ra: 16 mA
5/18/2015
S DNG SPAN HC, HC
INPUTSPAN
GI TR INPUT %
GI TR OUTPUT
OUTPUT SPAN
50 PSI
50 PSI 100 % 20 mA
16 mA25 PSI 50 % 12 mA
0 PSI 0 % 4 mA
5/18/2015
CHNH XC
chnh xc ni n mc gn nhau gia gi tr o v gi tr chun
chnh xc thng c th hin bng % span ca thit b o
Nu thit b o c sai s ln hn sai s cho php th cn phi sa cha, hiu chun, hiu chnh li.
5/18/2015
TNH TON CHNH XC
chnh xc = ( lch/span) x 100% V d: mt transmitter c di o 0 50 psi,
ng ra 4 20 mA. p sut vo l 25 psi, ng ra lc ny l 13,6mA. chnh xc c tnh nh sau: chnh xc = [(13,6 12)/16] x 100%
= 10%
5/18/2015
H S KHUCH I
H s khuch i = Output span / Input span
H s khuch i nh hng n chnh xc ca thit b
H s khuch i cao cho php HC, HC chnh xc hn
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3
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H S KHUCH I
V d: Mt transmitter nhit c thang o input 0 5000C v thang o tn hiu ra l 4 20mA. H s khuch i c tnh nh sau:l Span tn hiu vo: 5000Cl Span tn hiu ra: 16mAl H s khuch i = 16/500 = 0,032mA/0C
5/18/2015
CHM
chm c ngha l lp li hoc mc ti to sau cc ln o c lp ca cng mt gi tr thc
Kh nng to ra cc gi tr ra ging nhau vi cng mt gi tr vo cc ln o khc nhau
chnh xc thit b o cng cao th chm cng cao
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CHNH XC V CHM
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CHUN
xc nh chnh xc v chm ca thit b o, n phi c so snh vi chun bit.
Chun l thit b dng HC, HC cc thit b o khc m n c HC, HC v cp giy chng nhn bi cc t chc tiu chun quc gia hoc quc t:l ISA: International Standard Associationl NIST: the Nation Institute of Standard and
Technologyl ANSI: American National Standard Institute
5/18/2015
CHUN
Di o. Cp chnh xc. khng m bo o. n v. phn gii.
5/18/2015
SAI LCH ZERO
L trng hp tn hiu ng ra ca thit b o cao hn hoc thp hn gi tr mong i khi tn hiu vo t gi tr zero.
Kim tra sai lch zero thng d pht hin khi tin hnh HC/HC.
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4
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SAI LCH ZERO
V d: Mt transmitter c range: 0-500C
Gi tr input Gi tr outputim th Input Mong mun Thc t
10% 50C 5,6mA 5,8mA30% 150C 8,8mA 9,0mA50% 250C 12,0mA 12,2mA70% 350C 15,2mA 15,4mA90% 450C 18,4mA 18,6mA
5/18/2015
20mA 100%
80
60
40
20
4mA 0%0% 10 20 30 40 50 60 70 80 90 100%00C 500C
L tng
Thc t
SAI LCH ZERO
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SAI LCH SPAN
Xy ra khi span ca tn hiu ra khng tng ng vi span ca tn hiu vo
V d: Mt transmitter nhit c di o t 0 n 50oC, sai lch Span xy ra khi tn hiu vo l m tn hiu ra khng l
5/18/2015
20mA 100%
80
60
40
20
4mA 0%0% 10 20 30 40 50 60 70 80 90 100%00C 500C
L tng
Thc t
SAI LCH SPAN
5/18/2015
20mA 100%
80
60
40
20
4mA 0%0% 10 20 30 40 50 60 70 80 90 100%00C 500C
L tng
Thc t
SAI LCH SPAN
5/18/2015
S KHNG TUYN TNH
L trng hp m th quan h vo ra khng phi l ng thng
Khc phc s khng tuyn tnh khng phi l nhng iu chnh n gin m i hi phi sa cha
C th nhn bit s khng tuyn tnh nh bng s liu hoc th quan h vo/ra
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5
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20mA 100%
80
60
40
20
4mA 0%0% 10 20 30 40 50 60 70 80 90 100%00C 500C
L tng
Thc t
S KHNG TUYN TNH
5/18/2015
20mA 100%
80
60
40
20
4mA 0%0% 10 20 30 40 50 60 70 80 90 100%00C 500C
L tng
Thc t
S KHNG TUYN TNH
5/18/2015
20mA 100%
80
60
40
20
4mA 0%0% 10 20 30 40 50 60 70 80 90 100%00C 500C
L tng
Thc t
S KHNG TUYN TNH
5/18/2015
S KHNG TUYN TNH
Kh nhn dng Thng khng iu chnh c, i khi
vic iu chnh dn ti sa cha thit b
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Gi tr input Gi tr output
im th Input Mong mun Tng Gim
10% 20 psi 5,6mA 5,4mA 5,6mA
30% 60 psi 8,8mA 8,6mA 9,0mA
50% 100psi 12,0mA 11,5mA 12,5mA
70% 140psi 15,2mA 14,4mA 16,0mA
90% 180psi 18,4mA 17,0mA 19,0mA
SAI S HI SAI
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SAI S HI SAI
Ti cng mt gi tr ng vo, thit b s cho cc gi tr ra khc nhau ty thuc vo hng cp tn hiu vo (tng hay gim)
Sai s hi sai ch yu xut hin cc thit b o bng c kh.
Sai s hi sai nh hng n chm trong mt thit b o
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VNG KHNG NHY
L phm vi m tn hiu vo thay i nhng khng thy s thay i ng ra
Vng khng nhy c th nh hng n chm
C th gim vng khng nhy bng cch tng h s khuch i.
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V D - QUAN TRC GC
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V D - QUAN TRC GC
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V D - BO CO HIU CHUN
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V D - BO CO HIU CHUN
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V D - CHNG NHN KIM NH
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V D - CHNG NHN CHUN
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V D - CHNG NHN CA CHUN
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V D - CHNG NHN CA CHUN
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B TR THIT B CHO VIC HC, HC
Vic HC, HC phi ti to tn hiu vo ph hp vi cc thng s ca qu trnh cng ngh thc t
Thit b c HC, HC phi c lp t khi HC phi ging nh chng c lp t trong qu trnh thc t.
Mi lin h gia cc thit b trong h thng l hp l
Chun vo v chun ra phi ph hp
5/18/2015
B TR THIT B CHO VIC HC, HC
Ngun cp cho cc thit b trong h thng ph hp
u ni in phi m bo tip xc tt Phn p sut phi m bo khng r rCh : vic b tr lp t c hon ho,
phi hiu bit tt c chc nng ca thit b c HC trong qu trnh cng ngh ca n
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Ngun cp
Chun ng vo
Ngun cp
Thit b cn HC-HC
Chun ng ra
B TR THIT B CHO VIC HC, HC
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NGUYN TC HIU CHUN
Xc nh cc chun vo ra cho ph hp Tin hnh kt ni cc thit b theo ng s
HC To ra tn hiu vo th hin bin qu trnh
v a n ng vo ca thit b cn HC Ng ra ca thit b s hin th gi tr tng
ng
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NGUYN TC HIU CHUN
Thay i gi tr ng vo cc im khc nhau trn ton thang o
Ghi li cc gi tr ra tng ng v v th quan h vo ra
Da vo th nh gi sai lch v thc hin hiu chnh nu cn
Xc nhn li vic HC, HC bng cch kim tra li cc im va kim tra.
5/18/2015
NGUYN TC HIU CHUN
Ch : Tt nht l kim tra 5 im chia u trn
ton thang o theo chiu tng v chiugim: 0%, 25%, 50%, 75% v 100%
Phi bao gm im th 50%, im cao nhtv im thp nht
5/18/2015
NGUYN TC IU CHNH THIT B
iu chnh zero trc. Zero l im thp nht ca thang o ng dng
iu chnh span im cao nht ca thang o ng dng
iu chnh span c th nh hng ti zero, do sau khi iu chnh span phi kim tra li zero
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CHUN VO
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CHUN VO
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CHUN RA
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THIT B TO P SUT
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MT S THIT B CHUN
Lnh vc p sut d: Hin nay chun cao nht ca nc ta l p k pittng chun Ruska, di o
0.5-1000 bar chnh xc 0.004%
5/18/2015
MT S THIT B CHUN
Lnh vc chn khng v p sut tuyt i: Hin nay chun cao nht ca nc ta l p k pittng chun Ruska 2465, di o 14 mbar -70 bar tuyt i,
chnh xc 0.0008%
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MT S THIT B CHUN
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HIU CHUN NG H O P SUT KIU L XO V HIN TH S
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10
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ng h p sut dng ch p sut ti chca qu trnh
p sut tc ng vo phn t cm bin nhi lm n gin n v dui ra.
Ma st, s mi mn c th gy ra cc sailch nh sai lch zero, sai lch span, tr vs khng tuyn tnh
Hiu chun ng h p sut bao gm vichiu chnh cc b phn sao cho kim ch thch ng p sut vo.
HIU CHUN NG H O P SUT KIU L XO V HIN TH S
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Kim tra bn ngoi Kim tra cc ch tiu k thut Kim tra o lng
HIU CHUN NG H O P SUT KIU L XO V HIN TH S
5/18/2015
Kim tra bn ngoip k cn hiu chun phi tnh trng tt:
khng b n mn, bn, nt vMt knh trong sut khng c vt nt v cc
khuyt tt khc
HIU CHUN NG H O P SUT KIU L XO V HIN TH S
5/18/2015
Kim tra ch tiu k thutKim tra n v o, phn gii, cp chnh xc ca p k cn hiu chun
HIU CHUN NG H O P SUT KIU L XO V HIN TH S
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Kim tra o lngChn chun v cc phng tin phChun c gii hn o trn khng nh hn ca
p k.
khng m bo o hoc SSCBCP SSCBCP PT
Nhit mi trngt = 20 2 0 C vi PT c k < 0,4t = 20 5 0 C vi PT c k 0,4
HIU CHUN NG H O P SUT KIU L XO V HIN TH S
5/18/2015
Kim tra o lngXc nh s im hiu chun:k < 0.25 chn t nht 10 im0.25 k < 1 chn t nht 6 imk > 1 chn t nht 5 im
HIU CHUN NG H O P SUT KIU L XO V HIN TH S
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Ngun cp
Chun ng vo
ng h p sut
Ngun p sut
U NI
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U NI
5/18/2015
Kim tra o lngTrnh t thao tc:T t tng p sut n gii hn o trn caPT sau kha cc van li v gi nguyntrong 5 pht kim tra s r r p suttrong h thng.X p sut t t tr v trng thi ban u.iu chnh im 0 nu c th.Tng v gim p sut theo cc im nh
HIU CHUN NG H O P SUT KIU L XO V HIN TH S
5/18/2015
Kim tra o lngGhi cc kt qu vo bin bn hiu chun
Tnh ton s b v iu chnh li nu cn thitTnh ton khng m bo o ca PT
HIU CHUN NG H O P SUT KIU L XO V HIN TH S
5/18/2015
S DNG COMMUNICATOR CU HNH CHO TRANSMITTER
Commu-nicator
Transmitter 24VDC250 mA
+
-
Chun ng rap sut vo
Transmitter 24VDCmA +
-
Chun ng ra
p sut vo
S kt ni
5/18/2015
S DNG COMMUNICATOR CU HNH CHO TRANSMITTER
Cc chc nng chnh: t di o cho transmitter Chnh zero, chnh span Xem gii hn trn v di ca cm bin La chn kiu sensor vo i vi
transmitter nhit Loop test
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12
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HART V SMART DEVICES
Highway Addressable Remote Tranducer Cho php trao i tn hiu gia hai thit b,
cng vi tn hiu tng t (analog). c pht trin u nhng nm 80 bi
Rosemount Inc. Nay do HART Communication Foudation qun
l. Cc thit b hin trng c h tr HART =>
Smart Devices 5/18/2015
BT200 BRAIN TERMINAL
L thit b kt ni ring ca hng Yokogawa. C cc tnh nng v kt ni tng t nh HART
Communication. Khng c s ng h rng ri ca cc hng sn
xut thit b trn Th gii bng HART Communication.
5/18/2015
HC CHO TRANS. P SUTKIU IN T, TN HIU ANALOG
PV=p sut ti ng vo Span = URV LRV Output = 4mA khi PV = LRV Output = 20mA khi PV-URV
5/18/2015
U NI CHO TRANS. P SUT KIU IN T, TN HIU ANALOG
Ngun cp
Chun ng vo
Ngun cp
Transmitterp sut
Chun ng ra
Ngun p sut
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CHUN VO / RA
Chun vo l mt ng h p sut dng o vhin th p sut cp cho transmitter
Chun ra l mt ng h mA, dng o tn hiura tng ng vi cc gi tr p sut vo
Ngun p sut c cp t bm to p hoc tngun kh sau khi qua regulator
Cc chun vo ra phi c di o ln hn hoc bngdi o ca transmitter
Cc chun vo ra phi chnh xc cao hntransmitter theo quy nh
Ngun cp thng thng l 24VDC
5/18/2015
Kim tra bn ngoi Kim tra k thut Kim tra o lngCc mc trn yu cu tng t nh quy trnh
hiu chun p k l xo, hin th sChun ampe k c cp chnh xc cao hn t
nht 2 ln so vi b chuyn i.
QUY TRNH HIU CHUN
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Tnh ton s b chnh xc ca transmitter, nu khng t th tin hnh hiu chnh
HC zero trc, sau l span v kim tra li zero. C th phi chnh li zero sau khi iu chnh span
Sau khi zero v span tha mn, kim tra li cc im ln cui
HC CHO TRANS. P SUT KIU IN T, TN HIU ANALOG
5/18/2015
Ch : Ngun p sut c tng t t trnh p
sut vt qu di o ca transmitter Khi p sut tin gn n im mun kim
tra th dng nt chnh tinh ca bm to p iu chnh.
HC CHO TRANS. P SUT KIU IN T, TN HIU ANALOG
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TRANSMITTER P SUT CHNH LCH
5/18/2015
PV = PH - PL Span = URV LRV Output = 4mA khi PV = LRV Output = 20mA khi PV-URV
TRANSMITTER P SUTCHNH LCH
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U NI TRANSMITTER P SUT CHNH LCH
Ngun cp
Chun ng vo
Ngun cp
Transmitterp sut
Chun ng ra
Ngun p sut
5/18/2015
HC TRANSMITTER P SUT CHNH LCH
Ch : Cc yu cu i vi chun vo, ra tng t
nh trng hp ca transmitter p sutbnh thng
Qu trnh kim tra 5 im v hiu chnhging nh trng hp transmitter p sut 1 ng vo
p sut c cp vo ng p sut cao catransmitter
Ng vo p sut thp c thng vikhng kh
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HC LT BNG CT P TNH-NGUYN L
DP = rghr : Khi lng ringg : gia tc trng
trng (g = 9,8 m/s2)
h : cao ct p
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0m
10m
2m
HC LT BNG CT P TNH-NGUYN L
PV = DP LRV = 0mH20 URV = 8mH20
PV = DP LRV = 0mH20 URV = 10mH20
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HC LT BNG CT P TNH-NGUYN L
Bn xng, h=10mr = 737 kg/m3Py = 7.37 mH20Span = 7.37 mH20URV = 0 mH20LRV = 7.37 mH20
0m
10m
5/18/2015
Ngun cp
Chun ng vo
Ngun cp
Transmitter mc
Chun ng ra
Ngun p sut
HC LT BNG CT P TNH- U NI
5/18/2015
HC LT BNG CT P TNH- U NI
Ngun p sut c cp t bm hoc t ngun kh sau khi qua regulator
Ngun p sut ng thi c a n ng vo p sut cao ca transmitter v n chun vo ch th
Ng p sut thp ca transmitter c thng vi kh quyn
u ra ca transmitter c ni n chun ra
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CHUN VO RA
Chun vo l mt ng h o p sut Chun ra l ng h mA chnh xc ca chun phi ln hn
chnh xc ca transmitter
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KIM TRA 5 IM
Kim tra 5 im: Vic kim tra 5 im cng c thc hin
ging nh cc trng hp khcCc lu : Phi ch xc nh im zero v span
cho ng trong trng hp transmitter c lp t cao hn hoc thp hn mc ti thiu.
Transmitter o mc ch c th o c mc t v tr lp t tr ln 5/18/2015
HC FT THEO NGUYN L CHNH P
Nguyn l: Khi cht lng c lu lng khng i i
qua vng gii hn s tng vn tc v gim p sut
o p sut pha trc v pha sau vng gii hn s xc nh c lu lng nu bit trc c tnh ca cht lng
Ng vo p sut cao v thp ln lt c lp pha trc v pha sau thit b gim p
5/18/2015
HC FT THEO NGUYN L CHNH P
5/18/2015
HC FT THEO NGUYN LCHNH P
V d: Lu lng: 0 100 m3/h p sut to ra: 0 30 psi Span = 30 psi URV = 0 psi LRV = 30 psi
5/18/2015
Ngun cp
Chun ng vo
Ngun cp
Transmitter lu lng
Chun ng ra
Ngun p sut
U NI
5/18/2015
KIM TRA 5 IM
Xc nh cc im cn hiu chun v tnh ton cc P tng ng
P thc cht l p sut PH t vo ng p sut cao do ng p sut thp thng vi kh quyn
Qu trnh kim tra v hiu chnh hon tonging vi cc trng hp khc.
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HiU CHUN DISPLACER LEVEL TRAMSITTER
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HiU CHUN DISPLACER LEVEL TRAMSITTER
Gm hai phn chnh: B phn th ch (displacer): t trong mt bnh cha Ngp trong cht lng cn o mc
B chuyn i (transmitter) c ni vi displacer thng qua
mt n by
5/18/2015
HIU CHUN DISPLACER LEVEL TRAMSITTER
B phn th ch (displacer): Khi lng thay i khi mc cht lng thay i Khi lng ln nht khi mc cht lng thp
hn im thp nht ca n Khi lng nh nht khi ngp hon ton trong
cht lng B chuyn i (transmitter)
o khi lng ca displacer v chuyn ithnh tn hiu in u ra
Tn hiu in u ra t l thun vi mc chtlng trong bn
Di o: Bng vi chiu di ca displacer5/18/2015
HIU CHUN DISPLACER LEVEL TRAMSITTER
Khi mt vt c nhng vo cht lng, ditc dng ca lc y, khi lng ca vt sb gim i mt lng ng bng khi lngca th tch cht lng m vt chim ch.
Cng thc xc nh khi lng ca mt vt:m = d.v, trong y:m: khi lng ca vtd: khi lng ring ca vtv: th tch ca vt
5/18/2015
HIU CHUN DISPLACER LEVEL TRAMSITTER
Khi mt vt c nhng vo cht lng, ditc dng ca lc y, khi lng ca vt sb gim i mt lng ng bng khi lngca th tch cht lng m vt chim ch.
Cng thc xc nh khi lng ca mt vt:m = d.v, trong y:m: khi lng ca vtd: khi lng ring ca vtv: th tch ca vt
5/18/2015
HC NHIT K
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Kim tra bn ngoi Kim tra k thut Kim tra o lng
HIU CHUN NHIT K
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Cc mc tng t nh kim tra phn p kCh vic tng gim nhit Hiu chun nhit k cn thi gian tin hnh
tng i lu.
HIU CHUN NHIT K
5/18/2015
Ngun cp
Chun ng vo
Nhit k
Ngun to nhit
U NI
5/18/2015
U NI
5/18/2015
U NI
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ng h mV TC
Nhit k chun 1
Ngun nhit
Nhit k chun 2
HIU CHUN TC
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CHUN VO/RA
Nhit k chun 1 v TC cng c a vo khoang to nhit ca thit b to nhit
ng h mV o in p ra trn TC Nhit k chun 2 o nhit mi trng
ti u quy chiu. Gi tr ny dng b tn hiu ra ca TC
Cc chun ny phi c chnh xc v thang o ph hp
5/18/2015
KIM TRA 3 IM
TC khng th iu chnh, do ch kim tra v hiu chun
Thng ch thc hin kim tra 3 im:Nhit mi trngNhit gia thang oNhit gi tr trn ca thang o
Phi xc nh nhit mi trng trc khi a TC vo bn to nhit
nh gi chnh xc ca TC
5/18/2015
TNH TON B NHIT
Ghi li in p ch th trn ng h mV (tng ng vi nhit u o khi nhit mi trng cha c b v 0)
Tra bng tm mV tng ng vi nhit mi trng (c trn nhit k chun 2)
Cng hai gi tr trn ta c mV tng ng vi nhit u o khi nhit mi trng c b v 0
5/18/2015
KIM TRA HIU CHUN TC
Ch : Dy dn ko di ni TC vi ng h
o phi cng vt liu vi TC Cc yu t bt li nh hng n TC:
l S khng ng nht trong cu trc ca TC
l Tnh nguyn vn ca cc mi nil S r t nhin ca dy TC sau thi
gian di lm vic
5/18/2015
HIU CHUN RTD
m k RTDNhit k
chun
Ngun nhit
Vi RTD 3 dy hoc 4 dy, ta ni chung cc dy cng mu li khi ni vi m k
5/18/2015
CHUN VO RA
Nhit k chun v RTD cng c a vo khoang to nhit ca thit b to nhit
m k o in tr u ra ca RTD Cc chun ny phi c chnh xc v
thang o ph hp
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HC RTD KIM TRA 3 IM
RTD khng th iu chnh, do ch kim tra v hiu chun
Thng ch thc hin kim tra 3 im:l Nhit mi trngl Nhit gia thang ol Nhit gi tr trn ca thang o
Tnh ton chnh xc
5/18/2015
HC TT U VO TC U NI
Ngun cp
Chun ng vo
Ngun cp
Transmitternhit
Chun ng ra
Nhit (t bn to nhit
hoc t simulator)
5/18/2015
HC TT U VO TC U NI
CH : Nu dy TC c ni n transmitter th
u quy chiu nm transmitter Nu dng ngun pht mV thay TC th
ch cc tnh
5/18/2015
CHUN VO RA
Nu transmitter c ni n TC th chun vo l nhit k. Lc TC v nhit k c t chung vo bn nhit.
Nu dng ngun mV thay cho TC th chun vo l ngun pht mV
Chun ra l ng h mA Dng thm nhit k o nhit ti u
quy chiu dng vo tnh ton b nhit
5/18/2015
KIM TRA 5 IM
Xc nh 5 im kim tra (nhit u vo)
Xc nh in p tng ng vi 5 im nhit u vo ( b nhit)
Cp cc in p va tnh n u vo ca transmitter ln lt theo chiu tng ri chiu gim, ng thi ghi li gi tr u ra tng ng.
5/18/2015
TNH TON B NHIT
Dng bng tra TC tnh in p tng ng vi tng im o.
Dng bng tra TC tnh in p tng ng vi nhit u quy chiu.
Hiu s hai in p ny chnh l in p cp n ng vo transmitter cho im nhit ang xt.
Khi s dng calibrator cp thng tn hiu nhit th khng cn b nhit.
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20
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HC TT U VO RTD U NI
Ngun cp
Chun ng vo
Ngun cp
Transmitternhit
Chun ng ra
5/18/2015
CHUN VO RA V KIM TRA 5 IM
Chun vo l mt ngun pht tn hiuging nh tn hiu RTD tht
Chun ra l mt ng h mAKim tra 5 im: Vic kim tra 5 im c thc hin
ging nh trng hp hiu chuntransmitter thng thng khc.
5/18/2015
LOOP CHECK4-20mA signals (Conventional, HART)
Mc ch: Xc nhn cc tham s ng dng l
chnh xc (span, alarm set point)
5/18/2015
LOOP CHECK4-20mA signals (Conventional, HART)
Analog Input Ti field:
l Dng Hart m phng tn hiu vo: 0%, 50%, 100% of span
l Dng thit b m phng m phng tnhiu vo: 0%, 50%, 100% of span
Ti trm iu khin:l Xc nhn gi tr c ca h thng K
(Control graphics / Faceplate)l Xc nhn cc gi tr thit lp alarm (HH,
Hi, Lo, LL)
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LOOP CHECK4-20mA signals (Conventional, HART)
Analog Output Ti trm iu khin:
l M Control Faceplate. l Chuyn sang ch Manuall Xut tn hiu ra: 0%, 50%, 100% of span
Ti field:l Xc nhn tn hiu nhn: 4, 12, 20 mA.l Xc nhn tc ng i vi thit b cui
(nu c)
5/18/2015
21
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LOOP CHECK Digital Input/Output signals
Mc ch: Xc nhn cc gi tr alarm set-point l
chnh xc (0 or 1 to alarm)
5/18/2015
LOOP CHECK Digital Input/Output signals
Digital input Ti field:
l Tc ng vo thit b (v d switches level, pressure, temperature, flow, Remote/Local, Start/Stop, etc.) nu c.
Ti trm iu khin:l Xc nhn gi tr ch th ti h thng
(Control graphics / Faceplate)
5/18/2015
LOOP CHECK Digital Input/Output signals
Digital output Ti trm iu khin:
l M Control Faceplatel Xut tn hiu ra ng, m thit b cui
Ti field:l Xc nhn tn hiu in p nhn cl Xc nhn tc ng ca thit b cui.
5/18/2015