Yanayin zafin gas yana rinjayar saurin ultrasonic a cikin gas, don haka matakin mita yana buƙatar gano zafin gas a wurin aiki. Don haka mita matakin kayan yana buƙatar gano zafin gas a wurin aiki, biyan kuɗi don saurin sauti.
Na'urar firikwensin mita yana jujjuyawa zuwa saman saman samfurin. A can, ana nuna su a baya kuma ana karɓar su ta hanyar firikwensin.