BO CO THIT B O P SUT1. Cu to nguyn l ca thit b o p sut1.1 Gii thiu Trong dy chuyn sn xut in nng ca nh my nhit in Mng Dng 1 h thng o lng p sut s s dng cc thit b o p sut c s ha chng c nhim v bin i cc tn hiu khng in thnh cc tn hiu in c quy chun t 4-20mA v cc ng h c c lp t trc tip ti hin th gi tr p sut ti v tr lp t.S cu trc ca 1 h thng o lng k thut s

1: i tng o2: Sensor l phn nhy cm bin i cc tn hiu khng in nh p sut, nhit , mcthnh cc tn hiu in sau c a n cc b Transmitter.3: B bin i c nhim v bin cc tn hiu t Sensor (in p, in cm, in tr ) thnh tn hiu in c chun ha t 4-20mA.4: Card I/O l card s dng tn hiu u vo mc ch ca chng l bin i tn hiu t analog thnh digital my tnh c s dng c v a n khi x l.5: Khi x l c nhim v gim st cc tn hiu u vo, so snh v tnh ton x l cc tn hiu u vo a ra gi tr qu trnh Pv cho khi hin th.6: Khi hin th c nhim v hin th cc gi tr tnh ton bi cc b tnh ton trong khi x l ln mn hnh dao din ca ngi vn hnh.1.2 Sensor v Transmitter (B chuyn i)Thit b o p sut thuc h EJA ca hng YOKOWAGA s c dng ti nh my nhit in Mng Dng 1.Cc thit b o p sut thuc h EJA u s dng 1 nguyn l o chung l da vo s chnh lch p sut .

B bin i p sut thng thng s c b phn chc nng.

a.Cm binChnh p sut gia ng xung p sut thp v ng xung p sut cao c cm nhn bi mng cm bin thng qua dung dch in y. Mng cm nhn ny di chuyn in cc ( in cc ng ) ca in dung vi sai t l vi chnh p sut cp vo. S khc nhau v in dung gia hai cc ca in dung vi sai c a n b bin i.

Gi s X l l dch chuyn ca tm mng cm nhn tng ng vi p sut cp vo nh hnh.X = A(-) (1)Vi A l hng s p sut cp vo ng xung cao ca mng p sut cp vo ng xung thp ca mngSau khong cch gia tm ca in cc c nh v tm ca in cc di chuyn ( mng cm nhn ) v l:= + X= + X l khong cch gia mng cm nhn v in cc cu c nh khi chnh p t vo = 0Din dung gia mng cm nhn (in cc di chuyn) vi mi in cc c inh, v tng ng nh sau = = (2) = = (3) hng s in midin tch b mt c nhDng in tng ng vi hai gi tr in dung , v l= = tn s gc in p kch thchKhi = c gi bng hng s bi in p iu khin = c t c nh sau= = hng s.= . (4)T (1) ,(2) ,(3) v (4)Do gi tr u ra t l vi chnh p sut

b.B bin i ( Transmitter )Mch b chuyn i s bin i tn hiu chnh p vo thnh 4-20mA ,tn hiu u ra t l vi chnh p a vo tng ca 2 dng in c gi khng i hiu s ca 2 dng in c bin i thnh tn hiu 4 -20mADCNu gi dng in khng i c iu khin chnh xc trong mch b n nh dng l v gi 2 dng c kch thch bi in p l v th gi tr dng in tng s l .Mch in ny s tnh ton s khc bit gia v thng khc 0Trong trng hp khc nu th mch in ny s thay i in p ca sng do OSC pht ra bng cch tch hp vi b khuch i. Dng in v cng thay i v in p kch thch thay i t l vi dng sng in p pht ra ca OSC. Do v thay i n khi .Mt dng in tng ng vi chy qua in tr iu chnh Span. Dng in u ra t 4-20 mA c c nh bin i hiu dng in trn thnh mt tn hiu in p bi b bin i I/V v sau mt s iu chnh n c bin i thnh tn hiu dng in bi b bin i.1.3 ng h cng h c l loi thit b c kh c thit k o p sut bn trong hoc chn khng ca bnh, b cha hoc h thng.i vi ng h o p sut s dng trong nh my in Mng Dng 1 c 2 loi ng h c chnh l loi da trn nguyn l Bourdon Tube v loi da trn nguyn l kiu mng. Kiu ng Bourdon l thit b o p sut khng cht lng.N c s dng rng ri trong nhng ng dng p sut tnh.Mt ng Bourdon bnh thng c cha 1 ng cong c h u vo p lc bn ngoi v s kt hp vi cc thnh phn c kh vi kim ch th u bn kia nh hnh di y

p lc bn ngoi hng vo ng v lm cho ng cong,dn n thay i cong ca ng.S thay i ny lin kt vi cc ch th s. Ngoi ra 1 mch o c th c km theo ng bin i p lc thnh cc tn hiu in p. a vo cc b chuyn i. ng h o p sut kiu mng da trn s bin dng n hi ca mng thay v mc cht lng o s khc nhau gia p sut khng bit v p sut chun.Mt ng h o kiu mng in hnh c cha 1 capsule chia mng nh hnh di y. Mt pha c m cho p sut bn ngoi Pext, pha cn li c kt ni n p sut bit Pref. S chnh lch p sut PExt-Pref s lm bin dng mng.

Mng c th c coi nh 1 a trong phn b u lc nh hnh di y

lch s ph thuc vo vt liu mng,tnh cht hnh hc v cc iu kin bin v ln ca ti1.4 Transmitter v Pressure Gauge1.4.1. EJA 510E,EJA 530EB chuyn hiu p sut tuyt i v tng i hiu sut cao EJA520E v EJA530E tnh nng cm bin n tinh th v rt ph hp vi o p sut cht lng,kh v hi. Tn hiu u ra 4-20 mA DC tng ng vi p sut o. N cng kh nng p ng nhanh, ci t t xa v gim st thng qua giao tip BRAIN hoc HART v kh nng t phn tch. Nn tng chun truyn thong Fieldbus cng c sn.Tt c lot sn phm EJA-E c cu hnh theo tiu chun ca chng, ngoi tr loi theo kiu Fieldbus c xc nhn tun theo tiu chun an ton SIL 2.a. Tiu chun k thut Gii hn bin v di o (i vi EJA510E,gi tr tuyt i v thp hn gii hn l 0)Bin /DiMPaPsi(/D1)Bar(/D3)Kg/cm2(/D4)

ABin 10 200kpa1.45 - 290. 1- 20.1 - 2

Di-100 - 200kpa-14.5 29-1 2-1 2

BBin 0.1 214.5 2901 201 - 20

Di-0.1 - 2-14.5 - 290-1 20-1 20

CBin 0.5 1072.5 14505 1005 100

Di-0.1 10-14.5 1450-1 100-1 100

DBin 5 - 50720 - 720050 - 50050 - 500

Di-0.1 50-14.5 7200-1 500-1 - 500

Thng s v hiu sutDa trn hiu chnh bin , tuyn tnh u ra, phn vt liu t m S v du silicon tr trng hp c cp n.i vi kiu truyn thng Field, s dng hiu chnh di thay v bin theo nhng thng s di y.Tham kho s chnh xc ca iu chnh bin (bao gm nh hng tuyn tnh ca thit b u cui, tr v kh nng lp li)Bin oABCD

Cp chnh xcBin X0.15% ca bin

Bin X(0.015 URL/bin )%bin (0.024URL/bin )%bin

X20 kpa (2.9 psi)0.2 MPa(29 psi)1 MPa(145 psi)8 MPa(1160 psi)

URL (gii hn trn)200 kpa(29 psi)2 MPa(290 psi)10 MPa(1450 psi)50 MPa(7200 psi)

Khi /HAC c ch rBin oABCD

Cp chnh xcBin X0.075% ca bin 0.1% ca bin

Bin X(0.015+0.006 URL/bin )%bin (0.02+0.0128URL/bin )%bin

X20 kpa (2.9 psi)0.2 MPa(29 psi)1 MPa(145 psi)8 MPa(1160 psi)

URL (gii hn trn)200 kpa(29 psi)2 MPa(290 psi)10 MPa(1450 psi)50 MPa(7200 psi)

nh hng ca nhit mi trng trn mi C (F) (0.15% bin +0.15% ca URL) Tnh n nh 0.1% /1 nm (tt c u vn hnh iu kin bnh thng) nh hng ca ngun cp 0.005%/V (T 21.6 n 32 V DC,350) nh hng ca rungKhuch i ca v m 1 v 3t hn 0.1% ca URL khi kim tra theo yu cu ca IEC 60770-1 hoc ng ng vi mc rung ln (10 60 Hz 0.21 mm di dch /60 2000Hz 3g)Khuch i ca v m 2t hn 0.1% ca URL khi kim tra theo yu cu ca IEC 60770-1 vi ng dng thng thng hoc ng ng c rung thp (10 60 Hz 0.15mm di dch /60 500 Hz 2g) nh hng ca v tr lp tXoay mng cm nhn khng nh hng g.Nghing s lm thay i 0.21 kpa (0.84 in0) c th lm chnh xc bng cch iu chnh im 0. Thi gian p ng90 msKhi phn mm c ci t im zero v bao gm c thi gian tr 45ms(danh nh)b. Thng s k thut: u ra k thut s 2 dy 4-20mA DC vi, chun truyn thng BRAIN hoc HART FSK c t ln tn hiu 4-20mADi u ra 3.0 mA ti 21.6 mAGii hn u ra theo NAMUR NE43 c th thit lp sn bng cch chn chun C2 hoc C3. Cnh bo li (tn hiu u ra chun D hoc J)Tnh trng tn hiu u ra tng t li CPU v phn cngTrn mc thang o:110%,21.6 mA DC hoc hnDi mc thang o:-5%,3.2 mA DC hoc t hn Hng s thi gian (yu cu u tin)Hng s thi gian khuch i t 0.00 ti 100.00 s bi phn mm v c thm vo thi gian p ng. Giai on cp nhtp sut 45ms iu chnh gii hn 0Gii hn 0 c th c nng nn hoc xa b hon ton vi gii hn trn hoc di ca v bc. iu chnh im khng bn ngoiim 0 bn ngoi lin tc iu chnh vi phn gii tng 0.01% ca bin . t li di c th t ti ch s dng hin th k thut s bng cng tc ci t gii. Mn hnh hin th s nguyn(mn hnh LCD ,ngu nhin)Hin th 5 s,6 n v v biu barCh th s c cu hnh hin th 1 hoc n 4 theo chu k sau; Chnh lch p sut c o, %p sut chnh lch, thang o ca p sut chnh lch, n nh ca p sut. S thy phn lp t nh my. Gii hn p sut chu cV dng A,B v C:32 MPa V dng D:132MPa T chun onCPU li, phn cng s c, cu hnh li v vt qu di o i vi p sut chnh p, p sut n nh v nhit v.Cu hnh ngi s dng qu trnh cnh bo cao/thp i vi chnh p v p sut n nh lun sn c. c tnh tn hiu (Tn hiu u ra kiu D v J)Ngi dng c th cu hnh 10 u ra t 4-20 mA Chng ch SILLot b bin i EJA ngoi tr loi theo chun truyn thng Fieldbus c xc nhn ph hp vi tiu chun sau;IEC 61508:2000;phn 1 n phn 7iu kin lm vic bnh thng(vic ty chn c tnh hoc chp thun kiu c th nh hng n nhng gii hn). Gii hn nhit :-40 ti C (-40 ti F)-30 ti C (-30 ti F) i vi hin th LCD Nhit lm vic:-40 ti C (-40 ti F) m gii hn0-100% RH p sut ti a

Kiu vEJA510EEJA530E

A v B4 Mpa abs (580 pisa)4 Mpa abs (580 pisg)

C20 Mpa abs (2900 pisa)20 Mpa abs (2900 pisg)

D60 Mpa abs (8700pisa)60 Mpa abs (8700pisg)

Gii hn p sut lm vicGii hn p sut lm vic ln nht

Kiu vEJA510EEJA530E

A 200 kpa abs (29pisa)200 Mpa abs (29pisg)

B2 Mpa abs (290pisa)2 Mpa abs (290pisg)

C10 Mpa abs (1450pisa)10 Mpa abs (1450pisg)

D50 Mpa abs (7200pisa)50 Mpa abs (7200pisg)

Gii hn p sut lm vic thp nht

Ngun cp v ti yu cu (u ra tn hiu kiu D v J.S la chn chc nng hoc kiu c th nh hng n yu cu thit b in)Vi 24 V DC cung cp, in tr ca ti c th ln n 550 c s dng

in p10.5 n 42 V DC cho s dng thng thng v kiu chng chy10.5 n 32 V DC cho bo v chiu sng (la chn kiu /A)10.5 n 30 V DC cho an ton ni b, kiu n, hocGii hn nh nht 16.6 V DC cho giao tip k thut s, BRAIN v HART Ti (Tn hiu u ra kiu D v J)0 n 1290 i vi vn hnh250 n 600 i vi giao tip k thut s Giao tip yu cuBRAINKhong cch giao tipLn n 2 km (1.25 dm) khi s dng polythilen cch nhit v cp PVCKhong cch giao tip ph thuc vo loi cp s dngDung lng in dung0.22 F hoc t hnDung lng in cm3.3 mH hoc t hnTr khng u vo ca thit b giao tip10 k hoc hn tn s 2.4 kHz

c. Thng s vt l Cc vt liu ch to chnhMng v vt liu kt ni xem bng (mu v tin t m) Cc vt ch to phVHp kim ng nhm vi polyurethane,sn mu xanh l cy m(Munsell 0.6GY3.1/2.0 hoc tng ng) hoc ASTM CF-8M thp khng g. Mc bo vIP66/IP67 ngPolypropylene Bc ca vng 0Nha cao su Buna (ty chn) Bin ghi tn v nhn316 SST Cht lng in voSilicon,du flo ha(ty chn) Khi lngKiu A,B v C: 1.2kg (2.6lb)Kiu D 1.4kg (3.1lb)

1.4.3 SS-3070 (ng h p lc cht lng in y)Di d rung mnh v s va p, ng h cha glycerin c cho l khng th s dng, tuy nhin, by gi, n s p ng vic o p sut ca bn di nhng iu kin k trn v vy ng h ny c th coi l ng h chnh xc nht tng c lm. Hon ton, bt kn bn trong v c in y bi glycerin trong sut v trng lng ring cao. Vi li th c tnh nht ca glycerin lm gim tc thay i v tr ca ng Bourdon, ng thi cng ng dng vo vic bi trn cc chi tit bn trong, s mi mn cng gim ng k, v vy n l ng h bn.

Di o (mm) :63,100,150Kiu < 100 bar : kiu C 100 bar : hnh chn c

1.4.3 SS-3030 ( ng h kiu mng kn)

Thng s k thut Di o (mm) :100,150 Cp chnh xc : 1%FS Di thang o :100 mm :0 0.5bar 40bar150 mm :0 150 mm0 2500 mm0 Nhit vn hnhMi trng: -20 +CTrung binh: ln nht +C Gii hn p sutn nh : gi tr thangDao ng : 0.9 * c thang o