Emkhakheni wokusebenza ngokuzenzakalelayo kwezimboni kanye nokulawula izinqubo, umkhiqizo ongu-4 - 20mA uyindinganiso evame kakhulu futhi ebalulekile yokudluliselwa kwesignali ye-analog. Ukuqonda izimiso zayo, izici, kanye nezinhlelo zokusebenza kubalulekile kochwepheshe kulezi zinsimu, kanye nanoma ubani onentshisekelo ekusebenzeni okuyinkimbinkimbi kwezinhlelo zezimboni zanamuhla.
Umphumela we-4 - 20mA ubhekisela ohlelweni lwe-electric current loop lapho isignali imelelwa ugesi wamanje oqondile (DC) ohluka phakathi kwebanga eliphakathi kwama-milliamperes ama-4 (mA) nama-20mA. Lapha, i-“mA” imele ama-milliamperes, iyunithi yamandla kagesi. Kulesi simiso, i-4mA ivame ukumelela inani elingu-zero noma elincane le-variable elinganisiwe, kuyilapho i-20mA ihambisana nenani eliphezulu. Isibonelo, ekusetshenzisweni kokuzwa izinga lokushisa, i-4mA ingase ibonise izinga lokushisa elingu-0 degrees Celsius, kanti i-20mA ingabonisa izinga lokushisa elingu-100 degrees Celsius, kuye ngokulinganiswa kwenzwa kanye nesistimu.
Isimiso ngemuva kokukhishwa kwe-4 - 20mA sisekhonweni layo lokudlulisa ulwazi emabangeni amade ngokuzwela okuphansi komsindo kagesi kanye nokuphazamiseka. Ngokungafani nezibonakaliso ze-analog ezisekelwe ku-voltage, ezingathinteka kalula ukumelana ezintanjeni zokudlulisa kanye nezinsimu zangaphandle ze-electromagnetic, izimpawu ze-current-loop zigcina ubuqotho bazo kangcono. Lokhu kungenxa yokuthi ugesi ogeleza ku-loop uhlala ungaguquki kungakhathaliseki ukumelana kwentambo, uma nje ukunikezwa kwamandla kunganikeza ugesi owanele ukunqoba ukumelana ku-loop. Inzwa ekugcineni komthombo we-loop, njengenzwa yokucindezela noma imitha yokugeleza, iguqula inani elibonakalayo elililinganisayo (ingcindezi, ukugeleza, njll.) libe ugesi ngaphakathi kobubanzi be-4 - 20mA. Lo gesi ube usuhamba ngesekethe yezintambo ezimbili noma ezine uye ekugcineni kokwamukela, lapho uguqulwa khona ube isignali esebenzisekayo, njengokufunda esibukweni noma okokufaka kohlelo lokulawula.
Enye yezinzuzo ezibalulekile zomkhiqizo ongu-4 - 20mA yikhono layo lokusekela amadivayisi “asebenza nge-loop”. Ekusethweni okusebenza nge-loop, izintambo ezimbili ezifanayo ezithwala isignali yamanje nazo zinikeza amandla ku-sensor noma ku-transmitter. Lokhu kwenza kube lula ukuxhuma futhi kunciphisa izindleko zokufaka, ikakhulukazi ezitshalweni ezinkulu zezimboni ezinezinzwa eziningi namathuluzi. Ngaphezu kwalokho, indinganiso engu-4 - 20mA ivumela ukuhlonza kalula amaphutha ohlelweni. Njengoba i-0mA ingeyona ingxenye yebanga lokusebenza elijwayelekile (ubuncane bungu-4mA), ukufundwa kwe-0mA noma ugesi ngaphandle kwebanga elingu-4 - 20mA ngokuvamile kubonisa inkinga, njengentambo ephukile, inzwa engasebenzi kahle, noma inkinga ngokuhlinzekwa kwamandla.
Umkhiqizo ongu-4 - 20mA uthola ukusetshenziswa okubanzi ezimbonini ezahlukahlukene. Embonini kawoyela negesi, usetshenziselwa ukudlulisa idatha kusuka kumapharamitha okuqapha izinzwa njengokucindezela kwephayiphi, amazinga okugeleza koketshezi, kanye namazinga ethangi kuya emakamelweni okulawula aphakathi. Ezimbonini zokukhiqiza, kusiza ekulawuleni nasekuqapheni izinqubo ezifana nokushisa, umswakama, kanye nokugcwala kwamakhemikhali kuma-reactor. Emkhakheni we-automation yokwakha, amasignali angu-4 - 20mA asetshenziswa ukuphatha izinhlelo zokushisa, ukungenisa umoya, kanye ne-air-conditioning (HVAC), ukulungisa amapharamitha ngokusekelwe ekufundweni kwezinzwa zemvelo.
Ekuphetheni, umkhiqizo ongu-4 - 20mA uyindlela eyisisekelo nethembekile yokudlulisa isignali ye-analog ezindaweni zezimboni nezokulawula izinqubo. Ukuqina kwayo ngokumelene nomsindo, ukusekela amadivayisi asebenza nge-loop, kanye nokulula kokuthola amaphutha kuye kwenza kwaba ukukhetha okuthandwayo kwezinhlelo eziningi, okuqinisekisa ukusebenza okubushelelezi nokulawulwa okuphumelelayo kwezinhlelo zezimboni emhlabeni jikelele. Njengoba ubuchwepheshe buqhubeka nokukhula, indinganiso engu-4 - 20mA ingahlanganiswa nezinqubo zokuxhumana zedijithali ezintsha, kodwa ukubaluleka kwayo endaweni yokwenza izinto ngokuzenzakalela kwezimboni okusekelwe ku-analog kusalokhu kuzinzile.
Isikhathi sokuthunyelwe: Ephreli-30-2025