Thermostat wani nau'i ne na na'ura mai sarrafa zafin jiki ta atomatik, yawanci yana ɗauke da sashin gano yanayin zafin jiki, ta hanyar faɗaɗa ko raguwa don kunnawa da kashe kwararar ruwan sanyaya, wato, daidaita ruwa ta atomatik zuwa cikin radiyo gwargwadon yanayin zafin ruwan sanyaya, canza kewayon zazzagewar ruwan sanyaya, don daidaita tsarin sanyaya ƙarfin watsawar zafi.
Babban ma'aunin zafi da sanyio na injin shine nau'in kakin zuma, wanda paraffin a ciki ke sarrafa shi ta hanyar ka'idar fadada zafi da ƙanƙantar sanyi don sarrafa yanayin yanayin sanyaya. Lokacin da zafin jiki mai sanyi ya kasance ƙasa da ƙimar da aka ƙayyade, ingantaccen paraffin a cikin ma'aunin zafin jiki na zafin jiki yana da ƙarfi, bawul ɗin thermostat ƙarƙashin aikin bazara don rufe tashar tsakanin injin da radiator, mai sanyaya ta cikin famfo na ruwa don komawa cikin injin, injin ƙaramin sake zagayowar. Lokacin da zafin jiki na sanyaya ya kai ƙimar da aka ƙayyade, paraffin ya fara narkewa kuma a hankali ya zama ruwa, ƙarar ƙara yana danna bututun roba don yin raguwa. A lokaci guda kuma, bututun roba yana raguwa kuma yana yin motsi sama akan sandar turawa. Sandan turawa yana da ƙasa a kan bawul don buɗe bawul ɗin. A wannan lokacin, na'urar sanyaya tana gudana ta hanyar radiator da bawul ɗin thermostat, sannan kuma yana gudana zuwa injin ta cikin famfo na ruwa don yawan wurare dabam dabam. Yawancin ma'aunin zafi da sanyio an shirya shi a cikin bututun fitar da ruwa na shugaban silinda, wanda ke da fa'idar tsari mai sauƙi da sauƙin fitar da kumfa a cikin tsarin sanyaya; Rashin hasara shine sau da yawa ma'aunin zafi da sanyio yana buɗewa kuma yana rufe lokacin aiki, yana haifar da yanayin girgiza.
Lokacin da injin aiki ya yi ƙasa da ƙasa (ƙasa da 70 ° C), ma'aunin zafi da sanyio yana rufe hanyar da za ta kai ga radiator ta atomatik, kuma ta buɗe hanyar da ke kaiwa ga famfo na ruwa. Ruwan sanyaya da ke gudana daga jaket ɗin ruwa yana shiga cikin famfo ruwa kai tsaye ta cikin bututun, kuma ana aika shi zuwa jaket ɗin ruwa ta famfo na ruwa don kewayawa. Saboda ruwan sanyaya ba ya bazuwa ta hanyar radiator, ana iya ƙara yawan zafin aikin injin da sauri. Lokacin da zafin aikin injin ya yi girma (sama da 80 ° C), ma'aunin zafi da sanyio yana rufe hanyar da ke kaiwa zuwa famfon ruwa ta atomatik, kuma yana buɗe hanyar da ke kaiwa zuwa radiator. Ruwan sanyaya da ke fitowa daga jaket ɗin ruwa yana sanyaya ta hanyar radiator sannan a aika zuwa jaket ɗin ruwa ta famfo na ruwa, wanda ke inganta ƙarfin sanyaya kuma yana hana injin daga zafi. Ana kiran wannan hanyar zagayowar babbar zagayowar. Lokacin da injin da ke aiki da zafin jiki ya kasance tsakanin 70 ° C da 80 ° C, manyan da ƙananan hawan keke suna kasancewa a lokaci guda, wato, wani ɓangare na ruwan sanyaya don babban zagayowar, da sauran ɓangaren ruwa mai sanyaya don ƙaramin zagayowar.
Ayyukan ma'aunin zafi da sanyio na mota shine rufe motar kafin zafin jiki bai kai ga al'ada ba. A wannan lokacin, ruwan sanyi na injin yana mayar da shi zuwa injin ta hanyar famfo na ruwa, kuma ana aiwatar da ƙananan wurare dabam dabam a cikin injin don sa injin ya yi sauri. Lokacin da yawan zafin jiki ya wuce na al'ada za'a iya buɗewa, don haka ruwan sanyi ta hanyar madaidaicin tanki na radiator don babban wurare dabam dabam, don saurin zafi.
