Zingaphi iingcali zenzululwazi ezifunekayo ukulinganisa ibhalbhu yesibane ye-LED? Kubaphandi beZiko leSizwe leMigangatho kunye neTekhnoloji (NIST) eUnited States, eli nani sisiqingatha sento ebiyiyo kwiiveki ezimbalwa ezidlulileyo. NgoJuni, i-NIST iqalile ukubonelela ngokukhawuleza, ngokuchaneka ngakumbi, kunye neenkonzo zokulinganisa umsebenzi wokuvavanya ukuqaqamba kwezibane ze-LED kunye nezinye iimveliso zokukhanya eziqinileyo. Abathengi bale nkonzo baquka abavelisi bokukhanya kwe-LED kunye nezinye iilebhu zokulinganisa. Umzekelo, isibane esilungisiweyo sinokuqinisekisa ukuba ibhalbhu ye-LED elingana nama-60 eewathi kwisibane sedesika ngokwenene ilingana neewathi ezingama-60, okanye iqinisekise ukuba umqhubi wenqwelo-moya yokulwa unombane ofanelekileyo wokukhanya.

Abavelisi be-LED kufuneka baqinisekise ukuba izibane abazenzayo ziqaqambile ngokwenene njengoko ziyilelwe. Ukufezekisa oku, linganisa ezi zibane ngefotometer, esisixhobo esinokulinganisa ukuqaqamba kuwo onke amaza obude ngelixa kuthathelwa ingqalelo ubuntununtunu bendalo beliso lomntu kwimibala eyahlukeneyo. Kangangamashumi eminyaka, ilabhoratri yeefoto ze-NIST ibihlangabezana neemfuno zeshishini ngokubonelela ngokuqaqamba kwe-LED kunye neenkonzo zokulinganisa ifotometric. Le nkonzo ibandakanya ukulinganisa ukuqaqamba kwe-LED yomthengi kunye nezinye izibane eziqinileyo, kunye nokulinganisa ifotometer yomthengi. Ukuza kuthi ga ngoku, ilabhoratri ye-NIST ibilinganisa ukuqaqamba kwebhalbhu ngokungaqiniseki okusezantsi noko, ngempazamo phakathi kwe-0.5% kunye ne-1.0%, ethelekiseka kwiinkonzo zolungelelwaniso oluqhelekileyo.
Ngoku, enkosi kuhlaziyo lwelebhu, Iqela le-NIST likuphindaphinde kathathu oku kungaqiniseki ukuya kwi-0.2% okanye ngaphantsi. Le mpumelelo yenza ukukhanya okutsha kwe-LED kunye nenkonzo yokulinganisa ifotometer ibe yenye yezona zibalaseleyo emhlabeni. Izazinzulu zikwalenze mfutshane kakhulu ixesha lokulinganisa. Kwiinkqubo ezindala, ukwenza ulungelelwaniso kubathengi kunokuthatha phantse imini yonke. Umphandi we-NIST uCameron Miller uthe uninzi lomsebenzi lusetyenziselwa ukuseta umlinganiselo ngamnye, ukubuyisela imithombo yokukhanya okanye ii-detectors, ukukhangela ngesandla umgama phakathi kwezi zibini, uze uphinde uhlengahlengise izixhobo zokulinganisa okulandelayo.
Kodwa ngoku, ilabhoratri ineetafile ezimbini zezixhobo ezizisebenzelayo, enye iyeyomthombo wokukhanya kwaye enye iyeyomtshina. Itheyibhile ihamba kwindlela yomzila kwaye ibeka i-detector naphi na ukusuka kwi-0 ukuya kwi-5 yeemitha kude nokukhanya. Umgama unokulawulwa kwiinxalenye ezingama-50 kwisigidi semitha enye (micrometer), emalunga nesiqingatha sobubanzi beenwele zomntu. UZong kunye noMiller banokucwangcisa iitafile ukuhamba ngokuzalana ngaphandle kwesidingo sokungenelela kwabantu okuqhubekayo. Yayidla ngokuthatha usuku, kodwa ngoku inokugqityezelwa kwiiyure ezimbalwa. Akusekho mfuneko yokutshintsha nasiphi na isixhobo, yonke into ilapha kwaye ingasetyenziswa nangaliphi na ixesha, inika abaphandi inkululeko enkulu yokwenza izinto ezininzi ngexesha elinye kuba i-automated ngokupheleleyo.
Ungabuyela e-ofisini ukuya kwenza omnye umsebenzi ngelixa iqhuba. Abaphandi be-NIST baqikelela ukuba isiseko sabathengi siya kwanda njengoko ilabhoratri yongeze iimpawu ezongezelelweyo. Umzekelo, isixhobo esitsha sinokulinganisa iikhamera ze-hyperspectral, ezilinganisa ubude bokukhanya ngakumbi kuneekhamera eziqhelekileyo ezibamba imibala emithathu ukuya kwemine kuphela. Ukusuka kwimifanekiso yezonyango ukuya kuhlalutyo lwemifanekiso yesathelayithi yoMhlaba, iikhamera ze-hyperspectral ziya zithandwa kakhulu. Ulwazi olunikezwa ngamakhamera e-hyperspectral asekelwe kwindawo malunga nemozulu yoMhlaba kunye nezityalo zenza ukuba izazinzulu ziqikelele iindlala kunye nezikhukhula, kwaye zinokunceda uluntu ekucwangciseni uncedo olungxamisekileyo kunye neentlekele. Ilabhoratri entsha inokwenza kube lula kwaye isebenze ngakumbi kubaphandi ukulinganisa imiboniso ye-smartphone, kunye nemiboniso yeTV kunye nekhompyuter.

Umgama ochanekileyo
Ukulinganisa ifotometer yomthengi, ooSonzululwazi kwi-NIST basebenzisa imithombo yokukhanya kwebroadband ukukhanyisa ii-detectors, ezikukukhanya okumhlophe okunobude bamaza amaninzi (imibala), kwaye ukuqaqamba kwayo kucace kakhulu kuba imilinganiselo yenziwa kusetyenziswa iiphotometers eziqhelekileyo ze-NIST. Ngokungafaniyo ne-laser, olu hlobo lokukhanya okumhlophe aluhambelani, nto leyo ethetha ukuba konke ukukhanya kwamaza ahlukeneyo akudityaniswanga. Kwimeko efanelekileyo, kowona mlinganiselo uchanekileyo, abaphandi baya kusebenzisa i-laser ezitshintshwayo ukuvelisa ukukhanya okunokulawulwa kwamaza okukhanya, ukuze kube mnye kuphela ubude bokukhanya obufakwe kwi-detector ngexesha. Ukusetyenziswa kwe-laser eziguqulwayo kwandisa umlinganiselo wesignali ukuya kwingxolo yomlinganiselo.
Nangona kunjalo, kwixa elidlulileyo, iilaser ezinokuthi zisetyenziswe ukulinganisa iiphotometers kuba i-laser ye-wavelength enye yaziphazamisa ngokwazo ngendlela eyongeza izixa ezahlukeneyo zengxolo kumqondiso osekwe kubude bobude obusetyenzisiweyo. Njengenxalenye yokuphuculwa kwelabhoratri, iZong yenze uyilo olulungiselelweyo lwefotometer enciphisa le ngxolo ukuya kwinqanaba elingahoywanga. Oku kwenza kube nokwenzeka ukuba kusetyenziswe iilaser ezinokutya okwesihlandlo sokuqala ukulinganisa iifotomitha ngokungaqiniseki okuncinci. Inzuzo eyongezelelweyo yoyilo olutsha kukuba yenza izixhobo zokukhanyisa zibe lula ukucoceka, njengoko i-aperture egqwesileyo ngoku ikhuselwe emva kwefestile yeglasi evaliweyo. Umlinganiselo wobunzulu ufuna ulwazi oluchanekileyo lokuba umkhangeli-lwazi ukude kangakanani nomthombo wokukhanya.
Ukuza kuthi ga ngoku, njengezinye iilabhoratri zephotometry, ilabhoratri ye-NIST ayikabinayo indlela echanekileyo ephezulu yokulinganisa lo mgama. Oku kungenxa yokuba indawo yokuvula yesixhobo sokulinganisa, ekuthi ukukhanya kuqokelelwe khona, kuchubeke kakhulu ukuba kungaphathwa sisixhobo sokulinganisa. Isisombululo esiqhelekileyo kukuba abaphandi baqale ukulinganisa ukukhanya komthombo wokukhanya kwaye bakhanyise umphezulu wendawo ethile. Okulandelayo, sebenzisa olu lwazi ukumisela le migama usebenzisa i-inverse square law, echaza ukuba ubunzulu bomthombo wokukhanya buhla njani ngokunyuka komgama. Lo mlinganiselo wamanyathelo amabini akulula ukuwusebenzisa kwaye wazisa ukungaqiniseki okongeziweyo. Ngenkqubo entsha, iqela ngoku linokuyeka indlela yesikwere eguquliweyo kwaye limisele ngokuthe ngqo umgama.
Le ndlela isebenzisa ikhamera esekelwe kwi-microscope, kunye ne-microscope ehleli kwinqanaba lomthombo wokukhanya kwaye igxininise kwiindawo zokumakisha kwinqanaba le-detector. I-microscope yesibini ibekwe kwi-workbench ye-detector kwaye igxile kwiimpawu zendawo kwi-workbench yomthombo wokukhanya. Qinisekisa umgama ngokulungelelanisa indawo yokuvula i-detector kunye nendawo yomthombo wokukhanya ekugxininiseni kwiimicroscopes zabo. Imakroskopu zinobuntununtunu ekungagxininisi, kwaye ziyakwazi ukubona nokuba kude kweemicrometer ezimbalwa. Umlinganiselo omtsha womgama uvumela abaphandi ukuba balinganise "ubukhulu bokwenene" bee-LEDs, okuyinombolo eyahlukileyo ebonisa ukuba ubuninzi bokukhanya obukhutshwe yi-LED buxhomekeke kumgama.
Ukongeza kwezi mpawu zintsha, izazinzulu ze-NIST zongeze izixhobo ezithile, njengesixhobo esibizwa ngokuba yi-goniometer ekwazi ukujikelezisa izibane ze-LED ukulinganisa ukuba kungakanani na ukukhanya okukhutshwa kwii-engile ezahlukeneyo. Kwiinyanga ezizayo, uMiller noZong banethemba lokusebenzisa i-spectrophotometer kwinkonzo entsha: ukulinganisa i-ultraviolet (UV) ukuphuma kwee-LED. Ukusetyenziswa okunokubakho kwe-LED ekuveliseni imitha ye-ultraviolet kubandakanya ukutya okufakwa kwi-irradiation ukwandisa ubomi bayo beshelufu, kunye nokubulala iintsholongwane emanzini kunye nezixhobo zonyango. Ngokwemveli, iradiation yorhwebo isebenzisa ukukhanya kwe-ultraviolet okukhutshwa zizibane zomphunga zemercury.