Recent Advancements in Digital Signal Processing Techniques Have Been Applied to the Science of Noise Control
Most mechanized equipment generates sound, noise and/or vibration in some form that may vary in pitch and volume. Although sound cannot be seen, its effects can be significant, ranging from mildly annoying and distracting to damaging. To ensure healthy work environments unnecessary noise needs to be identified with appropriate control measures put in place.
PAMI is equipped to provide advanced noise and vibration testing by blending the best of both traditional and leading edge technologies to identify the types and characteristics of noise along with identifying appropriate noise-control measures.
About Measuring Noise
Any machine that vibrates radiates acoustical energy that can be measured and quantified in three different ways:
- Sound pressure is created when a sound source radiates a pressure wave, and until recently this was the most widely available means of gathering output data from a source.
- Sound intensity is used to quantify how much noise is coming from a source (sound power per unit area), and to construct a map indicating magnitude and vector direction of acoustic energy.
- Mechanical vibration can be measured to identify and quantify the transmission paths of vibration induced noise.
Noise Measurement and Control Techniques
Different noise measurement and control techniques are available and applicable depending on the source and characteristics of the noise.
Frequency Spectrum: Every noise or vibration has its own frequency characteristic or fingerprint. Some are annoying and some can be damaging. PAMI can quickly and effectively identify and source the frequencies that should be eliminated.
Intensity Mapping: Once the characteristics of the noise are identified, PAMI can localize the critical noise emission areas as well as quantify the noise. Identifying critical areas provide a focus for a solution.
Priority Determination: By isolating and prioritizing critical locations of noise emissions, maximum benefit can be realized by attacking the worst offenders first.
Path Determination: Structural steel members act as an expressway for conveying noise. Any vibrating members can transfer sound over great distances, and this path needs to be broken to realize improvement.
Specialized techniques can be used to differentiate between structure and airborne noise, and to identify the primary contributor. Once the path of noise is determined PAMI can assist in providing the best location and method of noise-path interruption.
Sound Power Measurement: Sound power is an important characteristic used
increasingly to describe the sound emission from machines such as motors, fans, pumps, and hammer mills. PAMI’s equipment is able to measure the sound power of a single machine, even within a noisy environment, by canceling out other external sounds.
PAMI can apply its noise and vibration testing and control program in several situations:
- Sound level readings in any noise environment
- Noise reduction programs in factories
- Vibration level readings of machines and mechanical equipment
- Vibration reduction programs of machines and mechanical equipment
- Specifications and standards testing of products
- Building and structural acoustics.
Although the invisible nature of sound poses challenges in measuring and analyzing noise, the advanced technologies PAMI employs allow for accurately identifying the source and characteristics of noise, which help focus on design solutions.
The impact of design changes can be measured immediately, because PAMI’s measurement equipment provides instant visual interpretation of noise. The equipment is fully portable to measure noise in any environment, and versatile for quick configuration to measure sound pressure, sound intensity, and mechanical vibration. PAMI’s combined knowledge and advanced technology provide services to give clients the edge in the marketplace.