Ukulungisa Iqiniso: Iziproblemi Ezibalulekile Nokulungisa

Iziphumo Zokwenza Amandla Neziphumo Zokubona Isinyathelo

Akukhona Ngcono Noma Isinyathelo Esiphazanyayo: Ukufundwa Kwamandla, Ukuxhuma, Nenkinga Yeloopu

Izinkinga eziningi ze-transmitter zihlala zisuka kumaqondo amabili: ukungabi nalo umlando noma izwire elimiselwe. Kabefore konke okunye, qinisekisa ukuthi ivolti evela khona iyalingana nokuthi kufanele. Uma ishaya ngaphezulu kungaba ngu-10% noma ngaphansi, lokhu kungenza i-unit ikhulule kabeha. Thatha i-multimeter futhi ujonge uma kune-fuses epholile, amacircuit breakers ethuthile, noma lezi zikhathi ecorrode kahle esithandeni ukuzenzelela. Uma isiqiniseko siqale sishintshana kanjalo, kungenzeka kuyinto ethile engaqedi kangako. Jonga kabengelela lezi zikhathi noma lezi junction boxes apho izivibrashi zingasusa izinto ngomnyaka. Ukuphela kwezimali kuchaza ukuthi kukhona indlela yokuhlanganiswa ehlatshwayo. Faka imiphihlelo yokuqhubeka phakathi kwesilinganiso xa i-transmitter ayixhunyiwe. Konke okuphakade kungaphezulu kuka-50 ohms kusho ukuthi kungenzeka kube khona i-wire ebishiwe noma into ethile enhlelekile. Abasebenzisa izinhlelo ze-4-20 mA kuphela, qinisekisa kabeshuku ukuthi ivolti ye-loop iqinisekise ukuthi ithuthela i-transmitter inqobo yokusebenza kakade. Hlalani ukuthi uvavanye kuqala ngalo loop simulator ukuze ubone ukuthi ingcamango iphila kwi-wiring yasefield noma kwisebenzo esebenzayo. Ukuwubhala wonke lokhu kusukela ekufakeni izixhumanisi kususa amakhanda ayinkimbilibili emva kwalokho uma kudingeka ukulungisa izinkinga.

Ukucindezeka Kwesigina, Ukungcola, Nenkayizi: Ukubona I-Ground Loops, I-EMI, Namaqondo Amadoda

Imiphumela yombuzo wokungahleli kakhulu ihlanganisa izizathu ezimbili eziphakeme: amandla okugcina kancane kanye nomthwalo womoya (EMI). Uma uhlola izindawo zokugcina, qaphela ukuthi kunezinkinga zokuphazanyika kwesiseko esingaphezu kwe-volt 1 ngoba lezi zinkinga zingakha izindlela zezimali ezingavumelekileyo ezihlukunyeza ubumfihlo bokuthumeka. Ukuze uhlekele umphumela wezinkinga zokucindezela isiseko, ukufaka izigwebo esivumelekileyo sizothinta kabani. Noma kutheni ngokulungisa umthwalo womoya, abasebenzi basekhanda kumele bathintathe ukuthi icable ivale noma izinto ezifana ne-motors noma izinye i-drives (VFDs). Ukubuyisela ngaphandle kwefooti eyodwa kusosource sokuvula kakhulu kuthinta phansi kakhulu. I-twisted pair cable enenqobile iyasebenza ngokuhle uma umgca ohlolwayo ungagcinwa kuphela endaweni eyodwa. Ukulungisa izicathulo, mitha izilinganiso zokuxhumana kanye nezinkinga. Uma izilinganiso zibuyekeka ngaphezu kuka-15% kusuku sisetshenziselwe ngu-manufacturer, lokhu kusho ukuthi umfula wedwa wayede emva noma kukhona ukuchithwa kwesayensi. Ukufaka amandla e-ferrite emasango ye-input/ne-output ayethinta phansi izimfunzo eziphakeme. Kuzindawo ezikhona khona izimpahla zomoya, ukuthatha iqiniso eliqediwe kabili endleleni yamayeza engafakiwa akho kulayini yayikwenzela ukuthi ithinte phansi umthwalo ngaproximately 40 decibels. Abasebenzi basekhalenda balazi lokhu kuthinta phansi konke kakhulu ekugcineni ukuthumeka kwesiseko esihle.

Ukungapheli kukaCalibration nokuphula kukaAnalog Output

Izizathu Ezimbiliyo zokungapheli kukaZero/Span ku-4–20 mA Transmitters: Umbiko, Ukuwela Kwesikhathi, nokunqamula Kukungcola

Xa ukulinganiswa kuhlukumeza, kube kube kubonakala njengamaphutha wokuzero apho ivuli yeqiniso lingahlukile, noma amaphutha wokuspan apho amavuli wangaphandle akunye kuyiyingcwele ngaphandle. Lokhu kuhlukumeza kubekwe khona ngokushesha ngokuguquguquko kwegalimoto nezinkinga zezimoto ekhanda kumqondo. Amagugu kuyisidingo kakhulu ngoba izinto zihlukumeza zingaphakathi noma zingaphandle xa zihlangothi noma zingaphandle. Sibonile izimo apho ukuguquguquko kwegagasi ngaphezu kwezingu-30 ze-Celsius kungasebenzisa izikhungo ezingahlukumeziwe ngaphezu kwezingu-0.5% ngaphandle kwawo wonke umlando. Izinto zihlukumeza futhi ngexesha. Icapacitors ye-electrolytic zihlukumeza ngamazingu-20% ngexesha, okwenzekayo kungaba yinto ebalulekile ekwenzeni kazo. Ukufaka okungavumelekile kwenza indaba ehlukile. Uma izikhungo azifakwa ngendlela eyihambe ngayo, nokuhlukumeza okuncinane kumele kubaluleke kakhulu. Ngokwesithathu se-millimeter esingaphandle kwenye kungasebenzisa ivuli lezulu ngamazingu-1%. Konke lokhu kuhlukumeza kwenza amaphutha angavulekile ngaphandle kwemigaqo yokulinganisa, kwenza kungcono ukulungisa amavuli nezimodi zokulawula eziyingcwele emgangathweni.

Inqubo yokusebenza yokufaka inombolo: Ukulungiswa kwe-zero ne-span nge-loop verifier validation

Yenza ukulinganisa usebenzisa le nqubo eqinisekisiwe:

1. Ukuhlukanisa transmitter bese uxhuma i-loop umhloli ngochungechunge
2. Sebenzisa ingcindezi noma okufakwayo okuyi-zero point; lungisa ukufakwa kwe-zero trim kuze kube yilapho okuphuma kufundwa i-4.00 mA
3. Faka isicelo sokungena kwe-span-point; lungisa i-span trim ukuze iphume ngo-20.00 mA
4. Qinisekisa ukulandelana kwamazinga ku-25%, 50% no-75% wendawo
5. Imibhalo yemiphumela enedatha efana naleyo etholakele/engekho

Abahloli be-loop baqinisekisa ukuhlolwa ngaphansi kwezimo zangempela, bethola izinkinga ezifihliwe ezifana ne-ground loops ezibangela ukushintshashintsha kwe-±2 mA. Njalo yenza ukuhlolwa kokushisa okubandayo/kwesimo lapho izinga lokushisa liyinto eyaziwayo yokudonsa.

Ukuhluleka Kwezokuxhumana Kwe-Smart Transmitter

Izinkinga ze-HART Protocol: Izikhathi, Izingxabano Zamakheli Amadivayisi, Nezidingo Zokuvimbela I-Loop

Imiphango engaphezu kwesimo seHART ihluka kakhulu kusindiso sendlela esikhulunywa ngayo okungukuthi isiqinisekiso sesinyathelo kunokuba yizinto eziphazanywayo. Ithaimbhuwezi linjalo lasebenza xa isinyathelo siphansi kakhulu njengoba amakhabheli aphinde phezu kwe-1,500 imitha noma senzekile ukuthi kukhona ukumelana okuningi kwezinhlayiya ezimandla ekushintshaneni umugqa. Ingenhla eyijwayelekile yenzeka xa izinto ezimbili ziyenzela idilesi efanayo kuqaleketo elilodwa, okwenzela ukuthi isimo singalibuzi ngokwethu. Okubalulekile konke ukukhumbula ngamaphasi aseHART ukuthi kudinga ukuqhathaniswa okuphathelene okwanele phakathi kwe-250 ne-600 ohms ukuze kube khona ukuxhumana okuhle phakathi kwezimpawu. Uma izinombolo zingena ngaphandle kalesi simo, siqala sibone idatha ethulile noma nokungafanele kubiza izinto ngokuphelele. Kukhona indlela eqondene yokujonga ukuthi zonke izinto zinezihloko ezigcwele kusuku lokufakwa, futhi ukuchaza kuphela ukuqhathaniswa kwegama ngokusheshayo usebenzisa imetri yesilinganiso yokulinganisa ukucopheleka okuhle ukuze kube yisimo esikuphazanywayo.

Ukuchithwa Kwezimali Nokuhluka Kwemithetho Yomshini

Ukungena Kwamanzi, Ukucubeka, Nekushisa Kwesilinda: Isiphumo Esinika Emaziningeni Nezigaba Zokuphila Kwesithuthi

Ukuthi amanzi afula kusidenge kanye nokuthi kube khona ukuthi kuvela ubuchopho kuzinto zokusebenza kuyashisa kakhulu indlela equkile kanye nesimo sokwamukela izishayamano phakathi kwesikhathi. Xa izilinda zikaqala ukusheshwa, amanzi afika kugumba likhomba izinkinga eziningi. Sibona i-PCBs zikhubazeka kanti futhi lezinto eziphathelene kakhulu ziphinde ziphinde ziphinde ziphinde ziphinde ziphinde ziphinde ziphinde ziphinde ziphinde ziphinde ziphinde ziphinde ziphinde ziphinde ziphinde ziphinde ziphinde ziphondeka, lokhu kuyakhiqiza ukuthi izilinganiso liyekwe emuva ngeminyaka yemihla nezinsuku njengoba abaphatheleni bomlando bakhombisa emsebenzini wabo. Ukucopheka kwegazi kuyindlela enzima kakhulu ngoba kudla amakhonkco akhe elekthrikhili kanti futhi kahlelisa imithombo yesensori, kuyakhiqiza ukuthi ukulungiswa kungabi nemilo futhi kuhlale kuhlaselwa izinto zezinkane ngokushesha kunemilo. Izirhiswa zomphakathi ziqinisekisa ukuthi izixhumanisi eziqukethwe ziyingo ebuyiselwa ngaphezu kuka-40% okungenani kunazo ezenziwe ngendlela efanelekile ukuzivikela kumehluko. Ukuze kubeke kulezinkinga, abasebenzi basebenzisa kumele bakhethe izigaba ezigcwelewe IP66 noma okuphezulu kwezindawo apho kungafanele kube khona amanzi. Ukuthatha izinto ezijikelezayo njenge-316L stainless steel kuhlanganisa kunceda ukuvikela ukucopheka. Ukubheka ngokuthutshana kwebuthixo kwezilinda kufanele kube khona njengenye indlela yokuphila. Kanti futhi kumasevisi amakhulu apho ukulinganisa kuyisidingo esibalulekile kakhulu, ukufakwa kwe-O-rings ezimbili kanye nothando oluthile oluvikela amanzi kwenza izigaba eziningi zokuvikela kakhulu ukuthi amanzi angafuni ayafika. Lokhu okunjalo kokuvikela kuyakugcina ukulinganisa okuthembekile kusuku lokuqala kangangekusuku lokuphela kwesikhathi sokusebenza.

Isikhombisi Sokuqala

Kutheni okungcono kusobala noma ukukhanya okuphazamisekile kumthwaleri?

Okungcono kufana nokhudlwa kwesayizi, izikhwama ezingalungileyo, ifuse ezilahlwayo, iziqhamo ezivuthelayo, noma izikhungo ezithuthayo. Izinkinga ze-loop zingakha kakhulu izinkinga yosiko.

Ukusabalala kwe-signal kanye nomshumbi kusenzeka kanjani ekhishweni lezimali?

Ukuze ususe ukusabalala kwe-signal kanye nomshumbi, uqaphele izindlela zokugcina, sebenzisa i-cables enezikhungo neziphaphaza, sebenzisa izitholakalo ezifanelekileyo, kanti ungahle ngaphandle kwezixhumanisi ezinodonga omkhulu.

Kutheni ukuguquka kokulinganiswa kwi-4-20 mA systems?

Ukuguquka kokulinganiswa kwi-4-20 mA systems kukhona ngokumelene ngokuguquka kwesithunzi, izinto ezenzekile, kanye nodumo olwakhiwe.

Kutheni izinkinga ze-HART protocol communication?

Izinkinga ze-HART zisenzeka ngokungcolana kwe-signal njengezilingo eziphakeme, ukumtambozelwa kwegogo, izinkinga zegama leqhaweka, noma ukulinganiswa okungafanelekile kwe-loop.

Ukungena kwamanzi kushintsha kanjani ubaluleka kanye ubude bezinsuku zomthwaleri?

Ukungena kwezibubhu kungalenga ekucopheleleni, ukuphazamisa kwegasketi, ukusobala kwe-PCBs, ukuxidwa kwemikhangeli, futhi ekugcineni izilinganiso ezingavamile nokuphakama okufutshane kweekhontlelo.