Testing Times : Why & How We Measure Noise & Vibration
We’re going to look today at some of the practical aspects of how we measure noise & vibration and consider why it’s important that you should measure and, more importantly, understand the noise and vibration of your products
The current global economic situation means that times are tough for everyone. It’s now that you need a competitive edge; that little bit extra. You need that advantage that will convince your customers to choose your product over your competitors.
Plainly, there are many factors that influence a buyer. The visual design of an object is obviously very important, but what about the sound? Automobiles are a good example of products that need to sound right. Sure, a potential customer may really love that piece of shiny chrome trim, but perhaps they’ll be more influenced by the sound of the V8 or, maybe, the smooth silent ride.
While we concentrate mainly on automotive examples in this article, it’s the same around the house. Will a buyer really want a dishwasher that makes so much noise they can’t listen to the radio or a fridge that makes them jump every time it switches on and off? It’s all very well having the blackest, shiniest bevel on your 42″ TV, but what if the discerning customer thinks the sound isn’t good enough?
So, without further ado, let’s look at some of the many and varied examples of how we go about testing noise, vibration, harshness & refinement.
Noise is an important consideration when a consumer is selecting a new vehicle. It is therefore imperative that every aspect of the vehicle’s acoustic profile is thoroughly understood and refined.
An investigation was made of a sample of automotive components where some were exhibiting a high frequency “tick” or rattle during each operating cycle. This feature could be heard above the normal operating noise. The problem this posed was to measure and analyze components in an objective fashion and classify components as “good” or “bad”.
This video was sent to us by one of our customers. It shows how a Prosig P8000 was used to measure the vibration transmitted through different configurations of bicycle suspension. Two are traditional setups (a rigid bike and a dual suspension one) and the third is a new interconnected suspension (likened to a railway bogie).
Standards DIN 4150-2:1999-06 and DIN 45669-1:1995-06 provide a means of assessing the effect on human beings of vibration caused by vehicle traffic, trains both above and below ground, construction work and occasional impulsive type vibration caused by, say, blasting and the like.
Road noise (the noise produced by the interaction of tires and road surface) is in many circumstances the dominant noise experienced by vehicle occupants. The requirements for producing quieter roads and tires need to be balanced with the need to ensure that safety is not compromised.
The objective of the brake noise tests was to record the braking events of cars being driven on various types of road and classify those events according to their type (Groan, Creep or Squeal etc) and severity.
So there you have it! A quick tour of just a few of the whys and wherefores of measuring noise & vibration. As we said at the start, the theme of this post is automotive testing, but the same techniques of measurement and analysis are just as valid across a whole range of products from aircraft to mobile phones.
Please leave a comment if you have your own examples, stories or questions. Or if you’d like to know more about any of the above click the ‘Contact Us’ button on the left of this page.
Chris Mason
Latest posts by Chris Mason (see all)
- 5 Cool Acoustics Links - December 18, 2020
- Prosig supply high channel count data acquisition system to new RAL Space NSTF facility - April 16, 2020
- Prosig Student Project Prize for University of Portsmouth – 2018 - August 8, 2018
please send published articles and notes on vibration, noise and silencer designs
with warm regards
anantharaman k
india
Fantastic post, I really appreciated your professional manner of writing this post. Its extremely helpful and informative.