By　way　of　vibration　transducer　and　demodulation　device,　the　parameter　of　the　electric　current,　the　pressure,　the　flow　and　the　temperature　of　nitrogen　and　water　of　the　equipment　can　be　monitored,　comprehensively　and　the　goal　of　fault　diagnosis　and　maintenance　decision,　the　management　of　equipments　can　be　achived.　As　a　practical　example　described　the　monitoring　and　diagnosis　system　was　described　for　gear　box　pot　type　furnace　top　of　No.　5　BF　at　the　Ironmaking　Plant　of　WISCO.