Konke ukufakwa kukagesi nezinhlelo ezisebenzayo zidinga ukwenziwa kwezilinganiso eziphoqelekile zikagesi ukuze kutholakale isimo jikelele, ukuphepha nokusebenza kwamanethiwekhi kagesi, kufaka phakathi ukuqinisekiswa kwamapharamitha wokulwa nokufakwa. Kulezi zilinganiso, uzodinga ukusebenza nge-megohmmeter, idivaysi eyakhelwe ukutholwa kwesikhashana kokulimala kokufakwa. Ukuze usebenzise i-megaohmmeter, kuyadingeka ukutadisha izici zayo zobuchwepheshe, imigomo yokusebenza, ithuluzi kanye nezici ezithile.
Idivaysi ye-Megaohmmeter
I-megaohmmeter yithuluzi elakhelwe ukukala amanani amakhulu wokumelana. Isici sayo esihlukanisayo ukusebenza kwezilinganiso ngamazinga aphezulu akhiqizwa yisiguquli sawo esingama-2500 volts (ubukhulu bevolumu buhlukahluka kumamodeli ahlukene). Idivayisi livame ukusetshenziselwa ukukala ukumelana kokufakwa kwemikhiqizo yekhebula.
Noma ngabe uluhlobo luni, idivaysi ye-megohmmeter iqukethe izinto ezilandelayo:
- umthombo wamandla kagesi;
- ammeter enesikali sensimbi;
- buza lapho i-voltage evela ku-megohmmeter idlula iye entweni elinganiswayo.
Ukusebenza nge-megaohmmeter kungenzeka ngenxa yomthetho ka-Ohm: I = U / R. Idivayisi ilinganisa amandla kagesi phakathi kwezinto ezimbili ezixhunyiwe (ngokwesibonelo, izintambo eziwumbili ezi-2, umhlabathi oyinhloko). Izilinganiso zenziwa ngevolumu eyilinganisiwe: icatshangelwa amanani akhona wamanje nawamandla, idivaysi inquma ukumelana kokufakwa.
Iningi lamamodeli we-megaohmmeter anezikhala ezi-3 zokuphuma: umhlabathi (3), umugqa (L); isikrini (E). Ama-terminals Z no-L asetshenziselwa zonke izilinganiso zedivayisi, u-E wenzelwe ukukalwa phakathi kwezingxenye ezimbili ezifanayo eziphethe manje.
Izinhlobo zama-megaohmmeter
Kunezinhlobo ezimbili zama-megohmmeter emakethe namuhla: i-analog neyedijithali:
- I-Analog (pointer megaohmmeter). Isici esiyinhloko sedivayisi yi-generator eyakhelwe ngaphakathi (dynamo), eqalwa ngokujikeleza kwesibambo. Amadivayisi we-Analog afakwe esikalini ngomcibisholo. Ukumelana kokufakwa kukalwa ngenxa yesenzo se-magnetoelectric. Umcibisholo ubekwe kwi-eksisi ngekhoyili yozimele, ethintwa yinsimu yamazibuthe angapheli. Lapho i-yamanje ihamba phezu kwekhoyili yozimele, umcibisholo uphambuka nge-engeli, ubukhulu bawo obuhambisana namandla namandla kagesi. Uhlobo olubonisiwe lokulinganisa kungenzeka ngenxa yemithetho yokufakelwa kwe-electromagnetic. Izinzuzo zamadivaysi e-analog afaka ukulula kwazo nokuthembeka, ukungathandeki kuyisisindo sazo esikhulu nosayizi ocabangelayo.
- Digital (megaohmmeter kagesi). Uhlobo oluvame kakhulu lwamamitha. Ifakwe ngejenetha elinamandla lokudonsa elisebenza kusetshenziswa ama-transistors ensimu. Amadivayisi anjalo aguqula ukuguqula okukhona kube okwamanje ngqo; ibhethri noma inethiwekhi ingasebenza njengomthombo wamanje. Ukusampula kwenziwa ngokuqhathanisa ukwehla kwamandla kagesi kwisekethe nokumelana kweleveli kusetshenziswa i-amplifier. Imiphumela yokulinganisa iboniswa esikrinini sedivayisi. Izinhlobo zamanje zinomsebenzi wokugcina imiphumela kwimemori yokuqhathanisa eminye imininingwane. Ngokungafani ne-megaohmmeter ye-analog, i-elekthronikhi inezici ezibumbene nesisindo esiphansi.
Sebenza nge-megaohmmeter
Ukuze usebenze nedivaysi, udinga ukwazi ukukala ukumelana kokufakwa nge-megohmmeter.
Yonke inqubo ingahlukaniswa ngombandela ngezigaba ezi-3.
Ukulungiselela. Ngalesi sigaba, kuyadingeka ukuthi kuqinisekiswe izimfanelo zalabo abasebenza (ochwepheshe abaneqembu lokuphepha likagesi okungenani abangama-3 bavunyelwe ukusebenza ne-megohmmeter), baxazulule ezinye izindaba zenhlangano, bafundisise umjikelezo kagesi futhi bacime imishini kagesi, balungiselele amathuluzi nemishini yokuvikela.
Eyokuqala. Uhlaka lwalesi sigaba, ukuze kukalwe ngendlela efanele futhi ngokuphephile ukumelana kokufakwa, inqubo elandelayo yokusebenza nge-megohmmeter inikezwe:
- Ukulinganiswa kokumelana kokufakwa kocingo kokuxhuma. Inani elicacisiwe akufanele lidlule i-VPI (umkhawulo wokulinganisa ongenhla) wodivayisi.
- Ukubeka umkhawulo wokulinganisa. Uma inani lokumelana lingaziwa, kubekwe umkhawulo omkhulu kakhulu.
- Ihlola into ngokuntuleka kwamandla kagesi.
- Ikhubaza amadivayisi we-semiconductor, ama-capacitor, zonke izingxenye ezinokufakwa okuncishisiwe.
- Ukusula isekethe ngaphansi kokuhlolwa.
- Ukulungisa okufundwe ngemuva komzuzu wokulinganisa.
- Ukufundwa kokufundwa lapho kulinganiswa izinto ezinomthamo omkhulu (ngokwesibonelo, izintambo zobude obukhulu) ngemuva kokuqiniswa komcibisholo.
- Ukususa inkokhiso eqoqiwe ngokufika phansi ekugcineni kwezilinganiso, kepha ngaphambi kokunqamula ukuxhumana kwemikhawulo ye-megohmmeter.
Owokugcina. Kulesi sigaba, imishini ilungiselelwe ukusebenzisa i-voltage futhi kudotshwa imibhalo yokuthatha izilinganiso.
Ngaphambi kokuqhubeka nokukalwa, kufanele uqiniseke ukuthi idivaysi isebenza kahle!
Kukhona indlela yokubheka i-megaohmmeter ukuthola ukuthi iyasebenza. Kuyadingeka ukuxhumeka izintambo kwizikhungo zedivayisi futhi kufinyeze okuphumayo kokuphela. Ngemuva kwalokho ukuthunyelwa kwe-voltage kuyadingeka futhi imiphumela idinga ukubhekwa. I-megohmmeter esebenza lapho kulinganiswa isekethe efushane ibonisa umphumela "0". Ngemuva kwalokho iziphetho ziyaxoshwa bese kwenziwa izilinganiso eziphindaphindwayo. Inani "∞" kufanele liboniswe esikrinini. Leli nani ukumelana kokufakwa kwegebe lomoya phakathi kwemikhawulo yokuphuma yento. Ngokusekelwe kumanani walezi zilinganiso, singaphetha ngokuthi idivaysi isilungele ukusebenza nokusebenziseka kwayo.
Imithetho yezokuphepha lapho isebenza nge-megaohmmeter
Ngaphambi kokuqala ukusebenza ngemitha yokumelana, kufanele uzijwayeze ngokuphepha lapho usebenzisa i-megohmmeter.
Kunemithetho eminingana eyisisekelo:
- Izinketho kufanele zibanjelwe kuphela izindawo ezingazodwa ezivinjelwe iziteshi;
- Ngaphambi kokuxhuma i-megaohmmeter, kubalulekile ukwenza isiqiniseko sokuthi awukho ugesi ocingweni nokuthi akukho bantu abangagunyaziwe endaweni yokusebenza.
- Kuyadingeka ukususa i-voltage eyinsalela ngokuthinta umhlabathi ophathwayo wesekethe olulinganisiwe. Ukusongela akumele kunqanyulwe ngaphambi kokuthi kufakwe ama-probes.
- Wonke umsebenzi nge-megaohmmeter ngokuya ngemithetho emisha wenziwa kumagilavu wokuvikela ama-dielectric.
- Ngemuva kokulinganisa ngakunye, kunconywa ukuthi ama-probes axhunywe ukukhulula amandla asele.
Ukuze wenze umsebenzi nge-megaohmmeter ekufakweni kukagesi, idivaysi kufanele idlule ukuhlolwa okufanele futhi iqinisekiswe.
Ukulinganiswa kokumelana kokufakwa kocingo nentambo
I-megohmmeter ivame ukukala ukumelana kwemikhiqizo yekhebula. Noma abasebenza ngogesi be-novice, bekwazi ukusebenzisa le divayisi, akunzima ukuthi babheke ikhebula elingumgogodla owodwa. Ukuhlola ikhebula le-multicore kuzoba isikhathi, njengoba izilinganiso zenziwa ngakibo ngayinye. Ngasikhathi sinye, amathambo asele ahlanganiswa abe yinqwaba.
Uma ngabe ikhebula selivele lisebenza, ngaphambi kokuqhubeka nokulinganiswa kokungalingani kokufakwa kokufakelwa, kufanele linqatshelwe ekunikezelweni kwamandla kanye nomthwalo oxhunyiwe osuswe.
Amandla kagesi okulawula lapho ikhebula ligaywe yi-megohmmeter kuya ngevolthi yenethiwekhi esebenza kuyo ikhebula. Isibonelo, uma ucingo lisebenza ngevolumu yama-volts angama-220 noma angama-380, khona-ke uma kukalwa kubalulekile ukubeka i-volts yama-volts ayi-1000.
Ukuze wenze izilinganiso, iproco elilodwa kufanele lixhunywe engxenyeni yekhebula, elinye liye engalweni yezikhali, bese lisebenza ngogesi. Uma inani lokulinganisa lingaphansi kwama-500 kΩ, khona-ke ukufakwa kwe-wire kulimele.
Ihlola ukumelana kokushayela kwemoto
Ngaphambi kokuqala ukubheka imoto kagesi nge-megohmmeter, kufanele inikezwe amandla. Ukuze wenze umsebenzi, kuyadingeka ukunikeza ukufinyelela eziphethweni ze-windings. Uma i-voltage yokusebenza kwemoto kagesi ingu-1000 volts, kufanelekile ukubeka ama-volts angama-500 ukuthola izilinganiso. Okokukala, iphenyi elilodwa kufanele lixhunywe ezindlini zezimoto, elinye liphumele ekuphumeni ngakunye. Ukubheka ukuxhumana kwe-windings komunye nomunye, ama-probes afakwa kanyekanye ku-windings. Ukuxhumana kufanele kube nensimbi ngaphandle kokulandela upende nokugqwala.
Le i-athikili yolwazi eyisiqondisi kuphela. Imininingwane eningilizayo nenembayo itholakala emiyalweni yokusetshenziswa kwama-megohmmeter, amadokhumenti obuchwepheshe nawokulawula.
