Ka'idar firikwensin zafin ruwa:

Na'urar firikwensin zafin ruwa wani muhimmin sashi ne na tsarin sarrafa injin mota, wanda zai iya juyar da zafin jiki zuwa siginar lantarki kuma ya watsa shi zuwa tsarin sarrafa injin mota. Lokacin da zafin ruwa ya tashi, ruwan yana faɗaɗa, kuma takamaiman ƙarfin zafi na ruwa ya fi girma, yana haifar da juriya mai girma na firikwensin zafin ruwa. Ana gano wannan canjin juriya ta injin sarrafa injin, wanda ke sarrafa sigogi kamar allurar mai da lokacin kunnawa. A lokaci guda kuma, na'urar firikwensin zafin ruwa na iya gano yanayin zafi na antifreeze, yana taimaka wa direba ya fahimci yanayin aikin injin da yanayin aiki na tsarin sanyaya.
A takaice dai, ka'idar aiki na firikwensin zafin ruwa yana dogara ne akan haɓakar thermal da yanayin ƙanƙantar sanyi na ruwa. Lokacin da zafin ruwa ya tashi, haɓakar ruwa yana haifar da juriya na firikwensin zafin ruwa ya zama mafi girma, kuma ana gano canjin juriya ta hanyar sarrafa injin, don haka yana sarrafa yanayin aiki na injin.
Na'urar firikwensin matakin ruwa a cikin akwati yana isar da siginar matakin ruwan da aka ji ga mai sarrafawa, kuma kwamfutar da ke cikin mai sarrafa tana kwatanta siginar matakin ruwa da aka auna tare da siginar saita don samun karkacewar, sannan ta ba da umarnin "bude" da "kusa" zuwa bawul ɗin lantarki na samar da ruwa bisa ga yanayin karkatacciyar hanya don tabbatar da cewa kwandon ya kai matakin ruwan da aka saita. Bayan an kammala aikin shan ruwa, kwamfutar da ke cikin sashin kula da zafin jiki ta ba da umarnin "buɗe" ga bawul ɗin lantarki wanda ke ba da matsakaicin zafi, don haka tsarin ya fara dumama ruwan da ke cikin akwati. Don saita zafin jiki. Mai sarrafawa ya ba da umarni don rufe bawul, yanke tushen zafi, kuma tsarin ya shiga yanayin adana zafi. A cikin aiwatar da shirye-shirye, don tabbatar da cewa tsarin bai kai matakin ruwa mai aminci ba, mai sarrafa wutar lantarki na tushen zafi mai sarrafa ba ya buɗe bawul, don guje wa asarar zafi da haɗari.
Ruwan zafin jiki da firikwensin matakin ruwa sun ƙunshi sashin kula da yanayin zafin jiki da sashin kula da matakin ruwa, kuma an daidaita shi da na'urar ragewa a gaban bawul ɗin lantarki da na'urar dumama rotary don dumama. Ana shigar da firikwensin zafin ruwan motar akan jaket ɗin ruwa na toshewar injin ko kan Silinda kuma yana cikin hulɗa kai tsaye tare da mai sanyaya don auna zafin mai sanyaya na injin. Na'urar firikwensin zafin jiki da aka yi amfani da shi a cikin ma'aunin zafi da sanyio shine madaidaicin ma'aunin zafin jiki (NTC), wanda juriyarsa ke raguwa yayin da yawan zafin jiki ke ƙaruwa, tare da wayar da aka haɗa da ECU. Dayan kuma waya ce ta cinya