消(xiao)(xiao)聲(sheng)(sheng)(sheng)器(qi)(qi)（圖4-62）通(tong)常用于介(jie)質(zhi)放(fang)空管的(de)終(zhong)端，以消(xiao)(xiao)除可能因高壓高速(su)介(jie)質(zhi)的(de)放(fang)空而(er)產生的(de)噪聲(sheng)(sheng)(sheng)。通(tong)常包括蒸汽排氣消(xiao)(xiao)聲(sheng)(sheng)(sheng)器(qi)(qi)、氣體排空消(xiao)(xiao)聲(sheng)(sheng)(sheng)器(qi)(qi)、油浴式消(xiao)(xiao)聲(sheng)(sheng)(sheng)過濾器(qi)(qi)、電(dian)機(ji)消(xiao)(xiao)聲(sheng)(sheng)(sheng)器(qi)(qi)等。

  視鏡(jing)（圖4-63）通常用于冷(leng)卻(que)水(shui)管(guan)道(dao)和潤(run)滑(hua)(hua)油管(guan)道(dao)等，通過其透明(ming)的視窗可以觀察到管(guan)道(dao)內循環冷(leng)卻(que)水(shui)或潤(run)滑(hua)(hua)油是(shi)否在流動(dong)。