# Tag: time domain

## Analysis of Dynamic Engine Vibration – Angular Vibration in High Performance Engines

The analysis of dynamic engine vibration and the accurate measurement of angular vibration is a non-trivial task, as a more in-depth analysis of boundary conditions reveals. Tools for

## Using Source Contribution Analysis to analyze complex structural dynamics issues

Using Source Contribution Analysis (SCA) and Structural Animation (STA) in the DATS software for the analysis of complex structural dynamics This post uses Source Contribution Analysis (SCA) techniques

## Analysis of Airflow Instabilities in HVAC units

HVAC (Heat Ventilation Air Conditioning) units are devices used in various applications, such as cars, buildings, aircraft etc. They facilitate the transport and conditioning (heating, cooling, changing of

## How Do I Upsample and Downsample My Data?

This post covers how to upsample and downsample data and the possible pitfalls of this process. Before we cover the technical details let us first explain what we mean

## The Effect of the Nyquist Theory on Rotational Order Analysis

Nyquist theory is generally understood, but this understanding usually relates to time sampling and the conversion to the frequency domain. Rotational order analysis and the effect of the

## What is Operating Deflection Shape (ODS) Analysis?

Operating Deflection Shape (ODS) analysis is a method used for visualisation of the vibration patterns of a machine or structure caused by unknown operating forces. This is different from the study

## A Different Way Of Averaging – Time Synchronous Averaging

Assuming one wants a frequency spectrum from an acquired time measurement, it is generally accepted that averaging of a signal in the time domain is not very useful

## Quantifying Signals – Peak, Peak-to-Peak, & RMS metrics

Anytime you measure something which is changing with time, there are multiple ways to quantify the signal. For the purpose of this discussion, we will be talking about how

## Where Does The Noise In A Signal Come From?

When one thinks of noise in a signal, it is generally associated with having been added in some way to the amplitude of a signal.  This is not

## What is Synchronous (Angular) Sampling?

The term synchronous data is usually applied to vibration or acoustic data that is captured from an item of rotating equipment at regularly spaced angle intervals as distinct

## Understanding Filter Characteristics

Recently when discussing with an engineering student the characteristics of filters, it became clear that some confusion exists around this subject area. This note attempts to explain the differences

## Aliasing, Orders and Wagon Wheels

These days most people collecting engineering and scientific data digitally have heard of and know of the implications of the sample rate and the highest observable frequency in

## Amplitude And Energy Correction – A Brief Summary

Amplitude and energy correction has been and is a continuing point of confusion for many people calculating spectra from time domain signals using Fourier transform methods. The first