CTRL Systems UL101, Operator'S Manual, Page: 6 / 28

PRODUCT OVERVIEW
What is Ultrasound?
The UL101 Receiver uses the properties of ultrasound for inspection.
Ultrasound is sound with a frequency above the human hearing range.
Humans can hear sound with frequencies between 20 Hz (Hertz) and
20,000 Hz. Ultrasound is all sound above 20,000 Hz and cannot be heard
by humans. Ultrasound is created when there is:
•
Vibration
•
Impact
•
Turbulence
•
Friction
•
Electrical arcing or corona discharge
The UL101 Receiver has a reception with the center of frequency at 40
kHz, the optimal frequency for listening for different kinds of industrial
defects. The CTRL UL101 converts ultrasound into audible sound so the
user can diagnose the condition of critical equipment. The primary
properties of ultrasound that make it useful for diagnostic tools are the
following:
•
Rate of Attenuation – Ultrasound has a high frequency and
accordingly shorter wavelength, therefore ultrasound waves attenuate
more quickly than sound waves and do not travel as far as audible
sound.
•
Directionality – The reception of ultrasound waves with the UL101
Receiver is directional, which allows the user to pinpoint the exact
location of the problem.
•
Shielding - Ultrasound waves in air can be easily shielded and do not
travel easily around corners.
•
Early Detection - Ultrasound can be detected prior to audible sound,
allowing problems to be detected earlier than with other methods.
These properties allow the user to distinguish and isolate the ultrasound
of individual components and leaks for better equipment diagnosis. For
example, if there are two bearings that are next to each other, because
ultrasound attenuates rapidly, it allows the user to listen to each bearing
individually. If the user is looking for a gas leak and other ultrasounds are
competing, a simple piece of cardboard typically allows the user to block
competing sound so that only leaks in the area being tested are heard. It
is also possible to then pinpoint the exact source of the leak because of
directionality.
- 3 -