Ultrasound is now considered the perfect complimentary tool for other predictive maintenance technologies such as vibration analysis and infrared thermography. There is also an increase in the number of individuals who are using ultrasound as a first line of defence to predict faults and failures in rotating equipment and electrical inspections.
Simply put, the instruments are listening devices. Airborne ultrasound instruments detect sounds that are not heard by normal human hearing. Average human hearing detects sound in the 16 to 17 kHz range. Ultrasound instruments listen for and detect sounds that are in the range of 20 kHz and above. The instruments actually listen for sounds that are above the threshold of normal human hearing. Ultrasonic sound waves are high frequency, low energy waves that are received by the instrument. The instruments then change or heterodyne the high frequency sound wave into an audible sound that is heard by the user through the headset which is plugged into the instrument. Since ultrasonic waves are high frequency and low energy, sources of ultrasound can easily be located amidst all of the ambient noise in a typical industrial facility. This allows us to identify a number of potential maintenance issues including:
- Mechanical bearing and greasing issues
- Air/gas leaks
- Electrical arching and tracking
- Steam trap and valve issues