Superior Signal Company LLC AccuTrak
®
VPE
User’s Manual
© 2015
9
BACKGROUND NOISE
The AccuTrak
®
VPE detects a narrow band of ultrasonic sound, therefore
although there may appear to be overwhelming background noise, the sound
may not be within the detection range of the instrument. Notice that you can
yell directly into the sensor and your voice will not be translated in the
headset.
The patented circuitry of the AccuTrak
®
VPE is capable of reproducing the
sound signature of the signal it detects. This means that the sound you hear
is closely related to the actual sound. It is an actual translation, not an
electronically synthesized tone, or “beep”.
Leaks
sound like a “hiss” or rushing sound, while
compressors
“chatter” a
rhythmical mechanical pattern. Fans should not produce enough wind noise
to interfere with leak detection. The fan motor
may produce a “buzz” or “hum”
which is a different sound than that of the leak.
Example: Mechanical vibrations sound very different from leak
sounds. Shake a set of keys, then take a short quick breath through
your nose. Listening to both sounds through the AccuTrak
®
is a good
example of how the direct translation process of the AccuTrak
®
helps
you to distinguish the difference between the two signals.
Practice listening to different components of your system, as this will help you
to identify the sound of a leak from other normal operational sounds.
Methods of reducing background noise interference:
Placing the flexible wave guide into the sensor port makes the reception of the
AccuTrak
®
more directional. This shields the sensor from competing sounds
entering from other directions. You can further shield background noise by
using something as simple as a clipboard or piece of foam from inside the
carrying case. Your angle of approach also effects results in loud areas. If
possible, always aim the instrument away from the source of background
noise and toward the suspected leak area.
Reducing the sensitivity suppresses the effect background noise has on the
display and headset. This helps make the leak sound more identifiable.
The most difficult background sounds come from areas of high turbulence
within a pipe. This can be where high velocity flow changes direction, or is
restricted such as within a partially closed valve. These situations naturally
produce high frequency sound which is very similar to the sound of the leak.
Use the standard methods for reducing background noise. If you are still
unsuccessful, then shut the system down. Although the pressure may be
somewhat reduced, it should still be sufficient for leak testing.
