ULTRASONIC
mainly two types of Vibration measurement: shaft vibration Bearing Vibration
the hearing range of human being is from 20hz to 20000hz
Ultrasound cannot be heard as it has a higher frequency than audible sound, with a frequency above 20000Hz.
if the vibration is above the range of human hearing which is about 20khz
anything over 20000hz
ultrasonographs
Vibration
The human ear can hear sounds between 20 Hz and 20,000 Hz because of the range of frequencies that the ear's sensory cells can detect and convert into neural signals. These frequencies cover the typical range of sounds produced by the human voice and most musical instruments.
Humans can hear sound frequencies between 20Hz to 20,000Hz because that range encompasses the typical frequencies produced by speech and environmental noise. Our auditory system is specialized to perceive sounds within this range efficiently. Frequencies outside this range are generally not relevant for communication and survival, so evolution hasn't equipped us to perceive them.
Thats the linear range of the probe
A good quality vibration meter can range anywhere from 60 dollars and up. You can find a good quality meter at the website www.coleparmer.com/catalog/product_index.asp?cls=7127.
There are many different ways to get a noise vibration analysis. There are several places that could do this for you, depending on where you live, and they have specialized toolkits you can buy to test it (but they are rather expensive, starting in the $2,000.00 range.)