Canjin matakin man fetur/ruwa shine na'ura mai mahimmanci da ake amfani da ita a aikace-aikace daban-daban don gano matakin man fetur ko ruwa a cikin tanki. Yana aiki ta hanyar amfani da hanyar iyo mai tashi ko faɗuwa tare da matakin ruwa. Lokacin da tudun ruwa ya kai matakin da aka riga aka kayyade, yana haifar da canji, yana aika sigina zuwa tsarin sarrafawa. Ana iya amfani da wannan siginar don fara ayyuka kamar fara famfo, kashe bawul, ko faɗakar da mai aiki. The matakin sauya yawanci sanya daga m kayan don jure matsananci yanayi kuma yana samuwa a cikin daban-daban iri, ciki har da inji, capacitive, da ultrasonic, don dace daban-daban ruwa iri da kuma tanki masu girma dabam. Yana taka muhimmiyar rawa wajen hana ambaliya da kuma tabbatar da ingantaccen aiki a masana'antu, motoci, da wuraren zama.