## Vibration Control and Isolation: A Comprehensive Guide for Engineers

[An Introduction To Vibration Analysis – Part 4] Welcome to the fourth part of our ongoing introduction to the world of vibration and acoustic measurement and analysis. In this post,…

## Modal Analysis in the Real World

[An Introduction To Vibration Analysis - Part 3] Modal analysis is one of the most widely adopted vibration measurement techniques for studying the dynamic behaviour of structures and mechanical components.…

## Vibration Measurement Techniques: A Comprehensive Guide

[An Introduction To Vibration Analysis - Part 2] Introduction This post on vibration measurement techniques is the second in our series, introducing vibration analysis. Future posts will continue the exploration…

## Measure Vibration – Should we use Acceleration, Velocity or Displacement?

When using vibration data, especially in conjunction with modelling systems, the measured data is often needed as an acceleration, as a velocity and as a displacement. Sometimes different analysis groups require the measured signals in a different form. Clearly, it is impractical to measure all three at once even if we could. Physically it is nigh on impossible to put three different types of transducer in the same place.

## Impact Hammer Double Hit – An Investigation

An Impact Hammer double hit is viewed as a common problem, and most hammer impact testing software offers a "Double hit" rejection function. Signals captured with double impacts are not…

## What Is A Hammer Test Or Hammer Impact Test?

A Hammer Impact Test is also known as a Modal Test, Impulse Test, Tap Test, Bump Test or, simply, a Hammer Test. It is a method of testing that allows…

## Some Basic Vibration Signal Qualities

This article discusses quantifying basic vibration signals from three aspects: signal type, signal level, and signal display format. Mathematical expressions and typical applications are also introduced. A simple harmonic vibration…

## Are My Hammer Impact Results Valid? (3) Time Invariance

As mentioned in our previous two articles, when performing experimental modal testing of a structure or component using impact (or ping) testing, it is important to consider and verify the…

## Accelerometer Selection – How To Choose An Accelerometer

Since DJB joined Condition Monitoring Technology Group (CMTG) in 2021 we have been able to bring new knowledge and capability to the group, especially when working alongside Prosig. We have…

## Accelerometer Cable Selection

The difference between Low noise and Non-Low noise accelerometer cables. It is important to use the correct cable when using accelerometers. A charge output accelerometer must be used with a…

Mass loading is the phenomenon whereby the mass of the Accelerometer alters the natural frequency of the test subject The video below demonstrates the phenomenon of mass loading and the…

## How Do I Calibrate An Impact Hammer?

The intention of this article is not to present any new scientific theories or ground breaking techniques, but to introduce new users to hammer impact testing and remind seasoned technicians of a method…

## How Do I Convert To Decibels?

Much confusion revolves around linear and non-linear numbers. The following outlines the mathematical process to convert from a number expressed in dB to a linear quantity. How do we convert to decibels and back again? (more…)

## What Type of Accelerometer Should I Use? IEPE, Charge or Bridge-based?

#### What type of accelerometer should I use? What are the advantages/disadvantages of a charge mode accelerometer, an IEPE accelerometer and a bridge based accelerometer?

There are so many types of accelerometer that is often difficult to know what type of accelerometer to use. An IEPE accelerometer will have a high pass filter at about 5Hz. The charge type will, by it’s nature have what is effectively a high pass filter at about 0.1Hz. Therefore neither type will show DC levels. The charge type will usually have a lower frequency bandwidth than the IEPE type. Charge accelerometers can be used at higher temperatures however. (more…)

## How do I find the natural frequency of an inlet manifold?

There are a number of ways to find the natural frequency (resonance) of a part like an automotive inlet manifold. Here are three different types of popular test techniques. But which one should you use and why?

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## How do I perform vibration analysis on a cylinder head and inlet manifold?

We were asked the following question…

I want to perform some cylinder head and inlet manifold vibration analysis, what should I do?

First we need to consider sensor selection (more…)

## Calibrating an Accelerometer with a Prosig P5000 system

Here we look at how to calibrate an accelerometer using a Prosig P5000 system. Put the wax on the shaker top. Place the accelerometer in the axis you wish to…

## How do I balance a shaft?

“How do I balance a shaft?” seems like a fairly straightforward question, but there are a number of things that we need to understand first. Here we look at a number of key concepts that need to be understood in order perform balancing.

### What does balance mean?

Well broadly speaking to balance a shaft, mass must be added or removed at certain angles. The concept being that the centre of gravity and rotational centre of the shaft will be equal when the shaft is balanced. (more…)

## New Hammer Impact Software – Preview coming soon

After listening to customer feedback, we have completely re-engineered the DATS Hammer Impact software. The new version will ship with the next DATS update (not the soon-to-be-released V7.0.23). In the meantime you will be able to download and preview the new package. You will of course need a P8000 system and a DATS licence with the Hammer Impact option enabled. (more…)

## How Do I Get An XYZ Resultant Waterfall

A user has three signals captured using a triaxial accelerometer and asked “What is the simplest way to get the XYZ resultant from run-up file?” He had tried forming a resultant of the raw time histories, but didn’t fully understand the resultant time history.

Of course, the correct way of processing the data is to calculate the individual waterfalls from the x, y & z data and then calculate a resultant waterfall. (more…)

## What is Source Contribution Analysis (or SCA)?

How do you measure the causes of a noise or vibration with respect to several sources? Which source is causing what part of the response?

For example, how does the noise inside the cabin of a vehicle relate to the engine noise or wheel hub noise and vibration? (more…)

## A Simple Step-by-step Guide To Bearing Vibration Analysis

Generally. when developing and testing bearings a simple step by step procedure should be followed.

## How To Calculate A Resultant Vector

When we are dealing with multiple measurements we often need to calculate a resultant vector to understand their combined effect. What do we mean by this? And how do we…

## [Video] How To Calibrate Microphones & Accelerometers

Here are two videos on a relatively simple, but sometimes misunderstood procedure – how to calibrate microphones & accelerometers (more…)

## Video: How To Calibrate Microphones & Accelerometers

Here are two videos on a relatively simple, but sometimes misunderstood procedure – how to calibrate microphones & accelerometers (more…)