SOLUTION SHEETHiDense PDA system

Flexible PDA solution with powerful and compact lasers

HiDense PDA system

The PDA solution for the most challenging particle sizing applications
Particle Dynamics Analysis (PDA) is a well-established technique to simultaneously
measure the size and velocity of spherical particles. The HiDense PDA is a complete
fiber-based PDA solution to precisely measure particles down to microns, with velocities
up to hundreds of meters per second, even with ultra-high particle densities and in harshenvironments. This makes it the ideal solution for studying particle behavior in complex
applications such as fuel sprays and flows with cavitation.

Key benefits•

Powerful laser and large aperture receiver to detect and accurately measureparticles down to 1 micron moving at up to supersonic velocity.

•

User selectable masks to optimize size range•

User selectable slits to optimize for high particle densities•

Splash-proof fiber based transmitter and receiver optics, ideal for large scale
sprays•State-of-art signal processor handles ultra-high date rates•

User-friendly software with powerful post processing and display options

The HiDense PDA solution in brief
Particle Dynamics Analysis (PDA) is an optical technique for non-intrusive
measurement of diameter and velocity of spherical particles. The transmitter
optics transmit two or more laser beams to the measurement volume,and generate an interference fringe pattern there. When a particle passes
through the interference pattern, it scatters light modulated in intensity.
The receiver optics collect scattered light, which is converted to electricalsignals by photomultipliers. The frequency and phase of this signal contain
information about the velocity and size of the particle.
The solution is based on four core components: Transmitting optics,
Receiving optics, signal processor and software. Each is designed for themost challenging applications.

PDA measurement in a dense fuel spray ina high pressure constant volume chamber(courtesy of LTT Erlangen, Germany)

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HiDense PDA solution

Transmitting optics
Compact, powerful all-in-one FiberFlow laser transmitter
Because the HiDense PDA uses high power lasers and a large aperture
receiver, you will be able to measure micron sized particles even in densesprays.
The laser transmitter is designed to maximize the laser power in themeasurement volume, providing the best possible signal quality.

FiberFlow Laser Transmitter and Probe

The FiberFlow probe can be configured with a range of focusing lenses,
to match the desired velocity and size measurement range. An optional
beam expander can further adapt the measurement range to best fit yourapplication.

Receiving optics
HiDense PDA receiver
The HiDense PDA receiver collects light scattered from the particles tobe processed later. The HiDense PDA receiver is designed with a large
aperture to allow maximum collection of light to improve the signal quality.
This is essential to collect weak signals from micron sized particles.
The HiDense PDA receiver includes a set of interchangeable spatial filters(slits and pinhole), with widths from 25 um to 200 um, mounted on aselector. They allow you to spatially filter the measurement volume in orderto handle different particle concentrations. The 25 um pinhole is designed
to cope with the ultra-high particle concentrations in dense sprays such as
diesel sprays.
The HiDense PDA receiver further includes three easily exchangeable
aperture masks, allowing you to optimize the size measurement range
without changing and realigning any optics.

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HiDense receiving optics with spatial
filter selector

Processor
Fast & powerful all-in-one processor

The Doppler signal collected by HiDense PDA receiver is processed by thesignal processor, to provide size and velocity results. The HiDense PDA
solution includes the new third generation Burst Spectrum Analyzer (BSA),
which uses the latest signal processing technology to be the fastest andmost powerful processor for PDA systems.
The new generation BSA is able to easily process signals with an input
frequency of up to 200 MHz and up to 160 MHz bandwidth. This makes
it possible to measure particles with wide velocity range and up to morethan 2000 m/s. The BSA handles particle rates up to more than 100,000 per
second, using the latest digital technology.
The HiDense PDA solution provides real time measurements and on-line
monitoring of Doppler bursts, spectra, size and velocity data, data rate,validation rate and more.
PDA measurements require accurate measurement of the phase differencesof light signals detected from different perspectives, which is processedby different channels inside the processor. This requires phase calibrationon the electronics. This process is fully automatic, with no effort from you.
In addition, the BSA automatically protects the photomultipliers against
saturation and potential damage from strong light reflections, extending
their lifetime and protecting your investment.

Spray nozzle quality control with
HiDense PDA system (courtesy ofLechler GmbH, Germany)

For further details on the processing performance, please consult separate
data sheet on “Burst Spectrum Analyzer (BSA)” on our website.

Data Analysis
Flexible and user-experience focused software platform
The BSA Flow software is comprehensive, easy to use, and includes
extensive graphics and data exchange features. The system setup including
the optical configuration as well as processor settings is controlled via thesoftware. Tools are provided which enables user-defined data analysis anddisplay, which is dynamically updated during measurements.
Data analysis can be customized with a built-in Calculation module aswell asa MatLab link for ultimate flexibility. Graphical output includes
vector plots, 2D line and scatter plots, and 3D plots. Graphic results can betransferred to a measurement report in pdf or HTML format. Numerical
output includes binary, ASCII, MS Excel, and TecPlot formats.
BSA Flow includes an automatic report function to help you quickly organize
and export the results. The user defines the plots and statistics to beincluded in the report and a PDF or html document is generated.
For further details on the software performance, please consult separate
data sheet on “BSA Flow Software” on our website.

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BSA Flow with Particle Sizingadd-on and Advanced Graphics
add-onTechnical specifications
OpticsLow power

High power

Laser wavelength532, 561 and 553 nm

532, 546 and 520 nm

Laser power				

100, 100 and 100 mW,
300, 300 mW and 200 mW

1 W for each laser

Laser Type		

Diode pumped solid state(DPSS)

Fiber laser

Transmitting optics Fiber Flow probe, (Diameter: 60 mm or 112 mm)
Receiving optics				

HiDense PDA fiber-based receiver probe: Diameter 112mm;
interchangeable spatial filters (3 slits + a pinhole); optionsof three masks to adapt different size range;

Focal lengths

160 mm, 240 mm, 310 mm, 500 mm, 800 mm, 1000 mm;			

All lenses are AchromaticProcessor

BSA P600

BSA P800

Max. input
frequency
Velocity range*)

120 MHz

200 MHz228 m/s

576 m/s

Data rate
Resolution>100,000 bursts/sec>16 bits*) depends on the optics, example for 112 mm probe with 500 mm focal length, 532 nm wavelength

SoftwareFeatures

BSA Flow

Online oscilloscope display of signals
Online display of data validation, data rate,coincidence rate, photomultiplier anode current
Set up of BSA processor
Acquisition of data from BSA,
Control of traversing system
Statistics of results (mean, RMS, Skewness andFlatness)
Listing of results
Set up of analysis sequences
Export of data

AdvancedGraphics Add-on

X-Y plots, vector plots, 3D plots, velocity profileplots

Particle Sizing Add-on

Add on for PDA measurement, data analysis andresult presentation

Solution Sheet SS_0494_v4. Subject to change without notice. Copyright © 2019.
Dantec Dynamics. All Rights Reserved. www.dantecdynamics.com