A cikin injunan konewa, duka tanadin mai da maganin iskar gas ba zai yiwu ba tare da kasancewar binciken lambda. Godiya ga waɗannan na'urori masu auna firikwensin, gurɓataccen injin yana raguwa sosai kuma yana da daɗi don amfani.
Binciken lambda, wanda kuma aka sani da firikwensin oxygen, yana da aikin auna bambanci tsakanin abun da ke cikin iskar iskar gas da iskar oxygen a cikin muhalli.
Wannan firikwensin yana da sunansa ga harafin λ (lambda) daga haruffan Helenanci, waɗanda ake amfani da su don wakiltar daidaici tsakanin ainihin ma'aunin iskar man fetur da ma'aunin da aka yi la'akari (ko stoichiometric) na cakuda. Lokacin da ƙimar ta ƙasa da ɗaya ( λ ) yana nufin cewa yawan iska ya kasance ƙasa da manufa, don haka cakuda yana da wadata. Lokacin da akasin haka ya faru ( λ > 1 ), don samun iska mai yawa, an ce cakuda ba shi da kyau.
Madaidaicin ma'auni ko stoichiometric, ta amfani da injin mai a matsayin misali, yakamata ya zama sassa 14.7 iska zuwa sashi ɗaya mai. Duk da haka, wannan rabo ba koyaushe bane. Akwai masu canji waɗanda ke shafar wannan alaƙa, daga yanayin muhalli - zafin jiki, matsa lamba ko zafi - zuwa aikin abin hawa kanta - rpm, zafin injin, bambancin ƙarfin da ake buƙata.
Binciken lambda, ta hanyar sanar da tsarin sarrafa lantarki na injin game da bambancin abun ciki na iskar oxygen a cikin iskar gas da kuma waje, yana ba shi damar daidaita yawan man da aka saka a cikin ɗakin konewa.
Manufar ita ce a cimma daidaito tsakanin wutar lantarki, tattalin arzikin man fetur da hayaki, kawo cakuda kamar yadda zai yiwu zuwa dangantakar stoichiometric. A takaice dai, samun injin yin aiki yadda ya kamata.
Ta yaya yake aiki?
Binciken lambda yana aiki sosai a yanayin zafi mai zafi - aƙalla 300 ° C - wanda ya ƙaddara cewa wurin da yake da kyau yana kusa da injin, kusa da ma'auni. A yau, ana iya samun binciken lambda kusa da na'ura mai canzawa, saboda suna da juriya da ke ba su damar yin zafi ba tare da zafin iskar gas ba.
A halin yanzu, injuna na iya samun bincike biyu ko fiye. Misali, akwai nau'ikan da ke amfani da lambda probes da ke gaba da bayan mai kara kuzari, don auna ingancin wannan bangaren.
Binciken lambda ya ƙunshi zirconium dioxide, kayan yumbu wanda idan ya kai 300ºC ya zama jagorar ions oxygen. Ta wannan hanyar, binciken zai iya gano ta hanyar bambancin ƙarfin lantarki (wanda aka auna a mV ko millivolts) adadin iskar oxygen da ke cikin iskar gas.
Wutar lantarki har zuwa kusan 500 mV yana nuna haɗaɗɗen raɗaɗi, sama da cewa yana nuna haɗuwa mai wadata. Ita wannan siginar lantarki ne ake aikawa da na’urar sarrafa injin, kuma ita ke yin gyare-gyaren da ya kamata ga adadin man da aka saka a cikin injin din.
Akwai wani nau'in bincike na lambda, wanda ke maye gurbin zirconium dioxide tare da semiconductor na tushen titanium oxide. Wannan baya buƙatar yin la'akari da abubuwan da ke cikin iskar oxygen daga waje, saboda zai iya canza juriya na lantarki dangane da ƙwayar iskar oxygen. Idan aka kwatanta da na'urori masu auna firikwensin zirconium dioxide, na'urori masu auna firikwensin titanium oxide suna da ɗan gajeren lokacin amsawa, amma a gefe guda, sun fi hankali kuma suna da tsada.
Bosch ne ya kirkiro binciken lambda a karshen shekarun 1960 karkashin kulawar Dr. Günter Bauman. An fara amfani da wannan fasaha a kan abin hawa a cikin 1976, a cikin Volvo 240 da 260.
Kurakurai da ƙarin kurakurai.
A zamanin yau, binciken lambda ba shi da mafi kyawun suna, kodayake buƙatunsa ba za a iya jayayya ba. Maye gurbinsa, sau da yawa ba dole ba, ya fito ne daga lambobin kuskuren da injin sarrafa lantarki ya haifar.
Waɗannan na'urori masu auna firikwensin sun fi juriya fiye da yadda suke bayyana, ta yadda, ko da lokacin da lambobin kuskure suka bayyana kai tsaye, suna iya haifar da wata matsala a cikin sarrafa injin, suna yin tunani game da aikin firikwensin. Don yin taka tsantsan da gargaɗin yiwuwar lalacewar abin hawa, sarrafa injin lantarki yana haifar da kuskuren firikwensin.
A cikin yanayin musanya, yana da kyau koyaushe a zaɓi na asali ko sanannen sassa masu inganci. Muhimmancin wannan bangaren yana da mahimmanci don ingantaccen aiki da lafiyar injin.