FFT Spectrum Analyzer
Vibration and Frequency Analysis

The Dewesoft FFT spectrum analyzer has it all: top performance, real-time FFT analysis, advanced cursor and marker functions, high freely selectable line resolution, flexible averaging, and advanced functions for in-depth frequency analysis. 

And, in addition to great performance, the Dewesoft FFT analyzer includes lifetime free software upgrades and the industry’s best 7-year warranty.

IEPE
IEPE
Charge
Charge
Voltage
Voltage
Sound
Sound
Sound pressure
Sound pressure
Pressure
Pressure
Counter and Encoder
Counter and Encoder
Torque
Torque
RPM
RPM
Acceleration
Acceleration
Strain and Stress
Strain and Stress
Video
Video
High-speed video
High-speed video
Thermal video
Thermal video
IP67
IP67
Shock rating 100g
Shock rating 100g
USB 2.0
USB 2.0
USB 3.0
USB 3.0
EtherCAT
EtherCAT
Ethernet
Ethernet
Wi-Fi
Wi-Fi

Highlights

  • REAL-TIME FFT SPECTRUM ANALYSIS: Dewesoft spectrum analyzers offer real-time FFT analysis on unlimited input channels. Flexible instruments from 1 - 1000's of channels are available.
  • UNLIMITED INPUT CHANNELS: Our DAQ systems offer virtually unlimited input channel configurations, and our DAQ software can perform FFT analysis on any or all of them at the same time.
  • GREAT FREQUENCY RANGE and FREQUENCY RESPONSE: DualCoreADC® technology boosts dual 24-bit delta-sigma ADC's with an anti-aliasing filter on each analog channel, achieving an astonishing 160 dB dynamic range in the time and frequency domains, with 200 kHz sampling rate per channel. 
  • AVERAGING: Overall (averaged) FFT with linear, peak, and exponential averaging or block-based calculation is available. Everything is enabled with the simple point-and-click user interface.
  • ANY LINE RESOLUTION: Selectable FFT line resolution up to 64k lines. This allows you to handle even the most demanding tasks.
  • CURSORS AND MARKERS: The FFT visual control can display values of the currently selected point with the markers. Available markers: maximum, free, zoom, sideband, harmonic, RMS, delta, and more. All markers create new channels that can be stored and used for additional analysis
  • CURSOR VALUE ESTIMATE: Innovative window interpolation technique allows precise amplitude and frequency estimation. Available in real-time as well as during post-processing and data review.
  • KINEMATIC MARKERS: Advanced envelope detection is used to identify the bearing frequencies and bearing faults, kinematic markers simplify fault detection during measurement. Create your own bearing sets in the database.
  • ADVANCED MATH: Auto spectrum, cross-spectrum, complex spectrum, waterfall spectrum, cepstrum (for bearing faults, speech processing), two-sided full FFT (for rotor whirl analysis), STFT (for non-stationary signals), envelope detection (for bearing fault analysis).
  • RICH VISUALIZATIONS: Our software offers real-time visualization widgets, such as 2D and 3D graphs with full customization options.
  • DEWESOFT QUALITY: Enjoy Dewesoft’s industry-leading 7-year warranty and world-class quality assurance. Your investment in the Dewesoft modal testing and analysis solution is protected.
  • DEWESOFT FLEXIBILITY: Connect additional sensors (strain gauge, force, temperature, CAN bus, GPS, and countless other data sources) and measure additional parameters simultaneously, with all data perfectly synchronized.
  • LIFETIME FREE SOFTWARE UPGRADES AND SUPPORT: Future-proof application and investment. Our award-winning DewesoftX software offers lifetime free software upgrades and support. Our FFT spectrum analysis solution is being constantly improved.

FFT Spectrum Analyzer Overview
Performance and Flexibility

Dewesoft FFT spectrum analyzers provide all main functions for spectral frequency analysis with advanced averaging, selectable resolution (64.000 lines and more), or direct specification of the bandwidth (e.g. 0.01 Hz). Multiple channels can be displayed and analyzed in real-time in a single FFT analyzer instrument. It also allows comparing FFT data easily. 

Dewesoft FFT analyzers offer either real-time direct online frequency spectrum analysis during the measurement or offline frequency analysis on the stored data. 

Check the video on the left to get a brief overview and see why our spectrum analyzer is the best performing and most flexible spectrum analyzer in the world. 

FFT Spectrum Analyzer OverviewPerformance and Flexibility

FFT Analysis
Application Overview

FFT analysis is one of the most often used techniques when performing signal analysis across one or more application domains. The FFT  transforms signals from the time domain to the frequency domain. FFT is the abbreviation of Fast Fourier Transform.

Using FFT analysis, numerous signal characteristics can be investigated to a much greater extent than when inspecting the time domain data. In the frequency domain, the signal characteristics are described by independent frequency components, wherein the time domain is described by one waveform, containing the sum of all characteristics. 

You can learn more about FFT analysis in our complete guide to FFT analysis.

FFT Analysis
Application Overview

FFT Analyzer Applications
Practical Uses for FFT Analysis

Inspecting measured data in the frequency domain is often the primary part of analyzing and monitoring signals. Data from a variety of sensors are used across virtually all industries in order to solve problems, optimize designs, test prototypes, monitor machinery, and many other jobs like the ones listed below:

FFT Analyzer Applications
Practical Uses for FFT Analysis

FFT Spectrum Analyzer Hardware
Vibration Meters and Sensors

Dewesoft offers flexible data acquisition systems with signal conditioners for the connection of any type of sensor that can record data and perform real-time FFT analysis. Amplifiers for connecting IEPE/ICP®, MEMS, charge accelerometers, strain gauges, microphones, tacho sensors, encoders, and other sensors are available.

Dewesoft FFT analyzers are available in many configurations:

  • Portable, all-in-one vibration analysis equipment: FFT analyzers with a built-in display, keyboard, processing computer, SSD data logger, and battery power supply.
  • Single- or multi-channel FFT analyzers: configure any number of input channels and perform FFT analysis in real-time.
  • Rack-enabled FFT systems: for large channel system and structural dynamics applications we offer 19” rack-mountable DAQ systems.
  • Benchtop FFT systems connected to PC: our benchtop FFT analyzers offer a simple connection to your PC computer via USB or Ethernet connection. From the smallest SIRIUS mini to inter-connectable modules with 8 channels each, and more.
FFT Spectrum Analyzer Hardware
Vibration Meters and Sensors

Typical Configurations
Of Dewesoft FFT Analyzers

Basic 4 channel vibration FFT analyzer:

  • SIRIUS Mini 3xACC, 1xACC+ data acquisition system
  • Up to four single-axis or one triaxial IEPE/ICP® accelerometers
  • Microphone (1x-4x)
  • 1x Tacho

Standard 8 channel vibration FFT analyzer:

  • SIRIUS DualCoreADC 6xACC, 2xACC+ DAQ system
  • Up to 8 single-axis or two triaxial IEPE/ICP® accelerometers
  • Microphones (1-8)
  • Tacho sensors (1-2)

Portable 8-16 channel vibration FFT analyzer:

  • SIRIUS R1DB or R2DB DAQ systems with SIRIUS DualCoreADC 6xACC, 2xACC+ signal conditioning slice
  • Up to 16 single-axis or 5 triaxial IEPE/ICP® accelerometers
  • Microphone (1-16)
  • Tacho (1-4)
  • Built-in computer and SSD data logger
  • Built-in display and keyboard
  • Li-ion battery powered

Advanced vibration FFT analyzer:

Typical Configurations
Of Dewesoft FFT Analyzers

FFT Analysis Software
Configuration and Setup

The DewesoftX FFT analyzer module allows several parameters to be set up before the calculation:

  • Output channels - complex, amplitude, overall RMS, and total RMS for user-defined frequency ranges
  • Calculation type - free, block history or overall
  • Windowing - Rectangular, Hanning, Hamming, Flattop, Triangle, Blackman, Exponent down, Transient, Blackman-Harris
  • Resolution - up to 64k lines 
  • Amplitude type - peak, peak-peak, RMS, PSD, Power, ESD, ASD
  • DC cutoff - removal of DC or low-frequency components
  • Overlap - define the percentage of time signal that has already been calculated and used it again for calculation
  • Weighting - Conversion of the output quantity from e.g. acceleration to displacement, and calculate the sound weighting in the frequency domain (A, B, C, D)
  • Averaging type - linear, exponential, peak-hold
FFT Analysis Software
Configuration and Setup

Cursors and Markers
Multipurpose Frequency Cursor Functions

The Dewesoft FFT analyzer allows setting multiple processing markers for automatic detection of different parameters. Our frequency analyzer offers the following markers:

  • Free marker: Free markers can be freely added. The marker shows us the axis position and the amplitude of the selected graph location.
  • Maximum marker: The maximum marker finds the highest amplitude in the spectrum.
  • RMS marker: RMS markers will sum up all the FFT lines in the selected band and calculate the RMS value.
  • Sideband marker: The sideband marker monitors the modulated frequencies to the left and right from the selected centerline.
  • Harmonic marker: Shows harmonics of the fundamental frequency, and can be used to investigate signal distortion and non-linearities. 
  • Damping marker: Damping markers are best to use in modal testing when we want to find out how our transfer curve is damped. We select it when we are interested in the quality factor, damping ratio, or attenuation rate of a selected peak.
  • Delta marker: shows the difference in channel values between two positions of the marker.
  • Kinematic marker: Advanced envelope detection is used to identify bearing frequencies and bearing faults. Kinematic markers simplify fault detection during measurement. Create your own bearing sets in the database. 
  • Zoom marker: Easily zoom in the selected region of the channel(s).
  • Vector cut marker: Outputs a user-defined region of a spectrum as a new channel.
  • Trigger marker: Outputs 0 or 1 depending on if the user-defined trigger level is exceeded by the related signal.

All processing markers work as derived math channels and will create new channels that can be stored and used for additional analysis.


Cursors and MarkersMultipurpose Frequency Cursor Functions

Window Functions
Spectral Leaking Reduction

Windowing functions reduce “spectral leaking,” which is caused by frequency components that fall outside or between spectral lines. DewesoftX FFT analysis software provides several popular and powerful Window type functions:

  • Hanning
  • Hamming
  • Blackman
  • Exponent Down
  • Flat Top
  • Rectangular
  • Blackman-Harris
  • Triangle
  • Transient
Window Functions
Spectral Leaking Reduction

Bearing Fault Detection
With Envelope Detection

Envelope detection is a standard procedure for the early detection of faults on ball bearings.

When a failure of the ball bearing occurs, it will produce ringing with a frequency that corresponds to its natural frequency. This ringing will repeat each time when a damaged part of the ball hits the ring or vice versa. In addition, the inner ring, outer ring, cage, and balls have different typical repeating frequencies depending on the geometry of the bearing and the rotational frequency. 

With DewesoftX data for bearing components are automatically managed by a bearing database. Using envelope detection and the bearing database simplifies pin-pointing critical frequency components related to specific bearing components and enables kinematic cursors to be used. 

Download Bearing Envelope Analysis brochure​​​​​​​.

Bearing Fault DetectionWith Envelope Detection

STFT
Short-Time Fourier Transform

Short-time Fourier transform or shorter STFT is a well-known technique in signal processing for analyzing non-stationary signals. STFT segments the signal into narrow time intervals and takes the Fourier transform of each segment. 

When the signal changes quickly, there is only a short time to calculate the frequency spectrum. But you still need good frequency resolution, and STFT is the solution. Using STFT better frequency resolution can be achieved during the same time frame compared to FFT.

STFT
Short-Time Fourier Transform

Full Spectrum Math
Two-sided Fourier Transform

Full Spectrum transform (aka “two-sided Fourier”) changes complex input signals from the time domain to the complex frequency domain. The input signal should be in the form of complex synchronous data (real & imaginary). Real and imaginary parts are usually gathered from two proximity probes installed along the X and Y axes. Traditional spectrum calculations provide no information regarding the direction of motion of individual frequency components on rotating shafts, but full-spectrum fills that gap.

Full-spectrum is used for signal modulation, signal demodulation, and rotor whirl analysis. 

The full spectrum transform can be performed on:

  • A single value or block history
  • Windowing
  • Overlap and DC cutoff
Full Spectrum Math
Two-sided Fourier Transform

Cepstrum Analysis
Determine Vibration Signatures

The cepstrum analysis calculation can be used to determine characteristics in speech analysis, and to enhance the analysis of vibration signatures such as gearbox and bearing frequencies. Dewesoft provides mirror spectrum, low and high-frequency outputs.

Dewesoft Cepstrum math offers settings for:

  • Selectable block size
  • Windowing
  • Liftering
  • Overlap and averaging

The video on the right side shows Cepstrum math being used on a microphone input signal to determine the speaker's name.

Cepstrum Analysis
Determine Vibration Signatures

Cross-spectrum and Auto Spectrum

The typically used results from FFT analysis are the Power spectra (Autospectra) determined from single individual input channels. If characteristics across multiple channels are required for analysis of correlation and phase relations, then cross power spectra are used.

With cross-spectra a reference channel is selected and cross-spectra is calculated for all channels relative to that reference channel.

Cross-spectrum and Auto Spectrum

PSD
Power Spectral Density

Power spectral density (PSD) is the measure of the signal's power content versus frequency.  

A PSD is typically used to characterize broadband random signals. The amplitude of the PSD is normalized by the frequency resolution.

Vibration Monitoring
And Machine Condition Monitoring

Dewesoft also provides great tools for long-term vibration and machine condition monitoring.  What Faults Can We Detect?

  • Bearing faults
  • Overheating
  • Shaft unbalance
  • Detached mounting
  • Gear-tooth failure
  • Load misalignment
  • Stator eccentricity
  • Other machine catastrophic failures

The Historian software package provides a time-series database for long-term data storage. The database can be either located locally, on the remote server, or in the cloud. The solution is based on the InfluxDB time-series database. Historian provides several features for your historic data:

  • Raw and reduced data: while raw data is always stored on the measurement unit for an in-depth analysis, a Historian takes the role of long-term reduced data storage into the cloud database.
  • Data safety and retransmit: if the connection between the measurement hardware and the database is lost, the data is safely stored locally on the measurement unit and then retransmitted to the database when the connection is available.
  • Trending and Analysis: Historical data can always be recalled and downloaded from the Historian database and used for trend analysis as well as for in-depth analysis and root cause identification.
Vibration Monitoring
And Machine Condition Monitoring

Sound Spectrum Analyzer
Additional Acoustics Analysis Options

Dewesoft FFT analyzer can also be used with sound and noise applications for sound spectrum analysis. Support for IEPE microphones makes sound measurement a breeze.

You can also freely mix FFT analysis features with other acoustics modules such as:

Sound Spectrum AnalyzerAdditional Acoustics Analysis Options

Great Investment
Future-Proof Application

Dewesoft FFT analyzers are a great investment for the future. Our solutions are constantly being improved, and new features are being added all the time. All updates to our FFT analysis software suite are free of charge. We offer lifetime free software updates and free software technical support.

Our industry-leading 7-year warranty on Dewesoft data acquisition systems means worry-free measurements for you. We are committed to ensuring that your investment in our measurement equipment was a good one - even when the unexpected occurs. 

Together with world-class data acquisition technology, Dewesoft provides the best FFT analysis solution your money can buy.

Great Investment
Future-Proof Application

FFT Analysis Resources
Training, Manuals, and Brochures

Check the following links for additional resources and material regarding our FFT spectrum analysis solution:

Brochures:

Manuals:

Training courses:

FFT Analysis ResourcesTraining, Manuals, and Brochures

FAQ

What is frequency analysis?

Frequency analysis is just another way of looking at the same data. Instead of observing the data in the time domain, frequency analysis decomposes time data in the series of sinus waves. Fast Fourier transform is a mathematical method for transforming a function of time into a function of frequency.
 

What is FFT (Fast-Fourier Transform)?

Fast Fourier transform is a mathematical method for transforming a function of time into a function of frequency. It is described as transforming from the time domain to the frequency domain.
 

Why are windowing functions used?

Window functions are used to reduce the effects of spectral leakage. Windowing is used to assign a weighting coefficient to each of the input samples, reducing those samples that cause spectral leakage. In effect, samples at the beginning and at the end of the sampling period are reduced to zero so that the discontinuities in the periodized sampled signal are removed.
 

Why should we use a Bearing cursor?

Bearing cursors are used to identify the bearing frequencies and bearing faults.

What kind of warranty do Dewesoft FFT Analyzers include?

All Dewesoft FFT analyzers come with an industry-leading 7-year warranty. We build our equipment to last. We guarantee you that your hardware will be free from defects and functional. Our warranty covers that the instruments function as promised for a period of 7 years from the day of the delivery.

Is signal recording and FFT analysis software included?

Yes! All Dewesoft FFT analyzers include DewesoftX Professional software with FFT analysis features free with no extra charge.
DewesoftX Professional includes advanced features for data storing, visualization, export, and also includes an extensive math library for signal processing.

Do Dewesoft DAQ systems really include lifetime free software updates?

Yes. All the updates to our software are free forever. We release a new major version every two months. All the performance updates, new features, and bug fixes are available for free to all existing Dewesoft users by simply download our installer from the website.

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