SOLUTION SHEETFlexPDA system

Particle size and velocity measurement solutions

PDA system for particle dynamics measurement applications
PDA (Particle Dynamics Analyzer) – also known as PDPA (Phase Doppler Particle Analyzer)
and PDI (Phase Doppler Interferometer) – is a well-established technique for thesimultaneous measurement of particle size and velocity. PDA works as an extension toLaser Doppler Anemometry (LDA). Both are optical techniques ideal for non-intrusive
point measurement in a wide range of fluid dynamics applications.
The FlexPDA solution inherits the best of PDA and LDA technology, resulting in a compact
best-value system for simultaneous particle size and velocity measurement applications.

Key benefits•

Factory aligned transmitter optics•

Receiving probe with optical fibers for maximum flexibility•

Wide particle size measurement range, from 1 - 500 µm•

State-of-art signal processor to handle the most demanding applications•

Advanced, flexible, and feature rich software platform with a user-friendly interface•

Automatic phase calibration for accurate size measurements•

Attachment rail and mounting mechanisms for alignment in any PDA application•Possibility to work completely as a standalone LDA system in backscattering mode•

Upgradable to other solutions

The FlexPDA solution
This solution is designed to deliver a complete entry-level PDA/LDA platform forparticle size and velocity measurement. The system can be configured for 1D or2D velocity measurements, and integrated with a 1D, 2D, or 3D traversing unit
for spatial mapping.
The solution is based on four core components: transmitting optics, receiving
optics, signal processor and software.
The transmitter optics convey two or more laser beams to the measurement
volume, generating an interference fringe pattern where the “point” measurement is made. When a particle passes through these fringes, it scatters light
modulated in intensity. The receiver optics collects the scattered light andsends it to the signal processor using optical fibers. Inside the processor, thelight signal is converted into an electrical one via photomultipliers, where thedigitized version of this signal in time is identified as a Doppler burst. Signal
processing techniques extract the frequency and phase of these bursts, whichcontain information about the velocity and size of the particle that can beanalyzed in software.

Frte
flFlexPDA system – basic setup for 1D and 2D solutions.

Various options are available for advanced synchronization, analog inputs,
velocity/particle size monitoring, independent processor control, and moreallowing additional flexibility to customize the solution to meet uniquemeasurement requirements.

Transmitting optics
FlowExplorer – turnkey, compact and calibrated laser transmitter

The FlowExplorer is a compact, turnkey LDA/PDA transmitter which uses diodelasers of 70 or 90 mW for each component.
Since the optics are factory aligned and calibrated, the system is the ideal solution
for applications requiring documentation of the measurement uncertainty.
The velocity calibration uncertainty is 0.11% (coverage factor 2). The velocity
resolution is better than 0.002% of the chosen velocity range. The FlowExplorer
can also be used as transmitter/receiver for pure LDA applications, giving theFlexPDA solution maximum flexibility.

FlowExplorer laser transmitter unit
with rotation support for alignment
with PDA receiver.

Receiving optics
Fiber PDA receiver

The FiberPDA receiving probe is designed to make PDA measurements acrossa wide range of applications. The FiberPDA employs a three-aperture mask anddetector configuration integrated into a single compact fiber-optic probe. A
fiber cable guiding three receiving fibers connects the receiving probe to thesignal processor, which contains the photomultipliers.
A compact, lowight-weight design makes the FiberPDA probe easy to handle.
It is factory aligned and requires no maintenance. A rugged fiber optics design
with sealed optical fibers prevents dust contamination for an extended lifetime.
An achromatic composite lens is used to focus the detected scattered light fromeach individual aperture onto a separate receiving fiber. This solution ensures
excellent transmission efficiency and signal quality.
Page 2FiberPDA receiver probe with rotation, tilt and translation support foralignment with LDA transmitter.

Measurement distances up to 400 mm are possible with standard front lenses.
Through an eyepiece, the user can see the spatial filter and the laser probe
volume, allowing precise and easy alignment of the PDA optics. The probe
is mounted on a support allowing quick coarse positioning as well as fineadjustment of rotation, tilt, and translation for perfect overlapping.

Processor
Burst Spectrum Analyzer (BSA) – fast and powerful all-in-one processor
The BSA F100 processor is a fast and powerful all-in-one processor. With
Ethernet, Wi-Fi and USB interfaces included, the processor can be connected
to a PC via a local area network, or a wireless or cabled connection. In large
facilities or in situations where remote access is required, these features makeit easy to have the processor near the experiment while keeping the PC at agreater distance away for safety and/or convenience. System setup is very easy
and user friendly: the setup is done directly in velocity units, based on a center
velocity and a velocity span value.
The BSA P100 processor has a maximum bandwidth of 5 MHz, making
it the right choice for a wide range of applications in sprays and particle
measurement. Depending on the optical configuration, the processor covers avelocity range up to more than 68 m/s. The BSA can handle date rates up to 100
kHz continuously and peak rates of 1 MHz.
Since the signals are analyzed by hardware/firmware inside the processor, theFlexPDA solution can provide real-time measurements. The user can monitor
Doppler bursts, spectra, size and velocity data, data rate, validation rate andother information on-line and in real time.
PDA systems require an accurate measurement of the phase differences oflight signals detected from different perspectives, which are then used toprovide the particle size measurements. Therefore, calibration of the electronics
is required to find and store the phase delays before data acquisition. This
process is handled automatically by the BSA processor whenever required.
The BSA processor includes an automatic overload protection feature for thephotomultipliers (PM’s). This protection quickly reduces the high voltage to
the PM’s when too much light is detected to prevent damage and extend thelifetime of these sensitive components. Please refer to the separate data sheet
for further details on the BSA processor.

Data analysis
BSA Flow Software – The most flexible and comprehensive software for PDA
measurements
The FlexPDA solution includes the latest and most modern acquisition andanalysis software for LDA/PDA applications, BSA Flow Software.
BSA Flow Software acquires, post processes, and presents data with extensivegraphical features. Measurement results can be displayed on-line duringacquisition in several formats such as Histograms, 2D/3D plots, Lists (individualresult statistics), and a software signal monitor to verify the measurement
quality.
The BSA Flow Software is intuitive and easy to use, thanks to its workflowbased user interface. Starting from the system setup, optical configuration andprocessor settings are controlled via software. Tools are provided which enableuser-defined data analysis and display, updated during PDA measurements.
Data analysis can be customized with a built-in Calculation module, withPython or via a MatLab link for ultimate flexibility. Graphical output includes
vector plots, 2D line and scatter plots, and 3D plots. Both plots and numericalresultscan be transferred to a measurement report in PDF or HTML format.
Numerical output includes binary, ASCII, MS Excel, and TecPlot formats. For
further details on the software performance, please see the data sheet on “BSAFlow Software” available at our website.
Page 3

Real time display of signals, datarate, valiation rate etc. with theSystem Monitor.

The Dantec Dynamics BSA Flow
Software is the most flexible andcomprehensive software for PDA
measurements.

Configurations
Item no.

Item name

Description

9061N0051

FlexPDA 1D

FlowExplorer 1D 90 mW
BSA P100 1D 660 nm
FiberPDA Receiving Probe 60 mm Diam., 5 m cable
Probe Support, Rotation for FlowExplorer transmitter
Probe Support, Rotation/Translation/Tilt for FiberPDA
receiver
L-Shaped Mounting Bench 1200 mm x 800 mm
BSA Flow Software
Advanced Graphics Add-on
Particle Sizing Add-on
Laser Alignment Eyewear
Laser Protective Eyewear
Front Lens for FlowExplorer (300 mm or 500 mm)
Front Lens for FiberPDA (160 mm or 400 mm)

9061N0061

FlexPDA 2D

FlowExplorer 2D 90/70 mW
BSA P100 2D 660/785 nm
FiberPDA Receiving Probe 60mm Diam., 5m cable
Probe Support, Rotation for FlowExplorer transmitter
Probe Support, Rotation/Translation/Tilt for FiberPDA
receiver
L-Shaped Mounting Bench 1200 mm x 800 mm
BSA Flow Software
Advanced Graphics Add-on
Particle Sizing Add-on
Laser Alignment Eyewear
Laser Protective Eyewear
Front Lens for FlowExplorer (300 mm or 500 mm)Front Lens for FiberPDA (160 mm or 400 mm)

Options
The FlexLDA system offers several options to meet the requirements of the application. The options include:
Processor upgrade: The BSA P100 processor can be upgraded to BSA P600 with
120 MHz max. frequency, or to BSA P800 with 200 MHz max. frequency, allowing formeasurements of higher velocities.
Software add-ons: Spectrum/Correlation Add-on, Cyclic Phenomena Add-on,
Scripting and MATLAB link Add-on, LIF and Parametric Analysis Add-on. Please see
the separate data sheet on our website.
Traverse: A software controlled automatic traversing mechanism with 1D, 2D or 3D
capability for flow mapping can be added to the system. Several standard traverse
controllers are supported in the software. Please see the separate data sheet on
our website.
Page 4

Technical specifications
Transmitter Optics

FlowExplorer

Laser

Diode

Laser power

90/70 mW (1D/2D)

Laser wavelength

660/785 nm (1D/2D)

Focal length

300 or 500 mm

Measurement volume dimensions

0.09 x 0.09 x 0.92 mm3 (300 mm focal length)0.15 x 0.15 x 2.55 mm3 (500 mm focal length)

Optics weight (excl. laser controller)

5 kg

Receiver Optics

FiberPDA
FiberPDA 60 mm receiver probe
Aperture masks for easy selection of size range
Maintenance free optical fibres

Focal length

160 or 400 mm

Optics weight (excl. fiber)

0.8 kgProcessor

BSA P100

BSA P600

BSA P800

Max. Velocity>40 m/s (300 mm
focal length)>68 m/s (500 mm
focal length)>130 m/s (300 mm
focal length)>220 m/s (500 mm
focal length)>390 m/s (300 mm
focal length)>660 m/s (500 mm
focal length)

Data rate>100,000 bursts/sec

Resolution>16 bitsParticle size range

from 0.5 µm >1 mm**Depends on the optical setup, scattering angle and fluid properties.

SoftwareFeatures

BSA Flow

Workflow-based user interface
Real-time oscilloscope display of signals
On-line display of data validation, data rate, coincidence
rate, photomultiplier anode current
Real-time end results thanks to multi-threading and decimation of displayed data
Set up of BSA processor
Acquisition of data from BSA
Control of traversing system
Statistics of results (mean, RMS, Skewness and Flatness)
Listing of results
Export of data

Advanced GraphicsAdd-on

Includes profile plots with confidence interval, vector
plots, contour plots, 2D plots, and more

Particle Sizing Add-on

Enables PDA measurement, data analysis and result
presentation

Solution Sheet SS_0738_v4. Subject to change without notice. Copyright © 2020.
Dantec Dynamics. All Rights Reserved. www.dantecdynamics.com