HELOS/R Series fully compliant with ISO 13320: 2009

Already since the early 90ties Sympatec contributes to the standardisation of laser diffraction (LD), image analysis, photon cross correlation, ultrasonic extinction, sampling etc. in the ISO/TC24/SC4.

The latest release of the updated ISO 13320 for laser diffraction instruments published at the end of 2009 was established with the co-operation of Sympatec. This standard replaces the former ISO 13320-1:1999 and highlights the request for traceablity of the results with respect to the standard metre in a strict sense. This is in-line with Sympatec's repeatedly published demands for accurate and precise LD instruments ([1], [2]).

Consequently our laser diffraction instruments are fully compliant with this new standard. The HELOS/R-series provides particle size data as close to the standard metre as physically possible both for dry and wet dispersion, using outstanding features: The strict operation in the parallel laser beam, where the reported particle size is not depending on the distance of the individual particles to the detector(s), as is the case in the inverse Fourier set-up. A detector integrating over 180° eliminates any errors caused by orientation of non-sphercal particles in the flow of the dispersers. The Sympatec own precision Mie evaluation has been used as an ultimate precise validation tool to proof the correctness of the MIEE code for the size range from <1nm to 10mm and the refractive index range from 0.2 to 3.0 for the real part and 0; 10^-5 to 8.0 for the imaginary part.

WINDOX 5.6 released

The latest WINDOX 5.6 software release supports all Sympatec instruments including those installed in validated environments. It is the first validated release covering the HELOS/R series with its unique new evaluation modes

• FREE (Fraunhofer
  Enhanced Evaluation),
• MIEE (the MIE Extended
  Evaluation) and
• RCM (the combination of measuring ranges).

All evaluations can be applied over the complete size range from 0.1 µm to 8750 µm, unique in the field of Laser Diffraction.

The diffracted light intensity is sampled continuously at 2000 scans per second with highest precision. Thus sophisticated trigger settings including a pre- and post-trigger on optical concentration and special intensity values are realised as well as time-sliced acquisition of particle size distributions down to 0.5ms. Consequently even quantities in the micro gramme range can be measured dry. Using statistical information on the reliability of the measured intensities, the optimisation of the inversion procedure is achieved.

This software also supports all recently released instruments including, e.g. the dynamic image analyser for wet process environments, PICCELL. Further more improvements in the automated evaluation of photon crosscorrelation (PCCS) results via the auto-NNLS mode have been included.

Validation Package with Tight Specifications available for HELOS/R Series

An adapted validation package is now available for the validation of the HELOS/R series. Sympatec's specifications for the Operational Qualification (OQ) exceed the requirements of the new ISO 13320: 2009. The specified quality limits

• ±3% for x₁₀ to x₃₀,
• ±2.5% for x₃₀to x₇₀, and
• ±4% for the x₇₀ to x₉₀)

may be extended by the errors provided with the standard reference materials used (typical in the range of several percent), However Sympatec strictly keeps the tighter limits for the HELOS/R series and Sympatec's reference materials are supplied without any additional tolerances.

Backward Compatibility of New HELOS/R Series Builds Bridges to the HELOS/F Series

Achieving results of particle size analysis as close as possible to the standard metre with the new HELOS/R-series of laser diffraction instruments as one of the much improved performance parameters, Sympatec maintains at the same time the highest degree of coherence to the results of the successful HELOS/F-series instruments. This not only indicates that the F-series instruments provide information very close to reality but also allows for simple migration between the R- and F-series generations.

HELOS/R and HELOS/F series can share the same software WINDOX 5.6 and their results in a common database. Furthermore, the new HELOS/R sensor can be switched to the Backward Compatibility Mode (BCM). In this mode not only the evaluation modes LD, HRLD and MIE are available, the results are almost identical to those of the existing HELOS/F series but with the benefit of latest electronic and mechanical improvements, e.g. high speed changing of measuring ranges and a TCP/IP network link of the instrument to the computer.

Vice versa using the standard WINDOX 5.6 software on a HELOS/F instrument allows for the presentation of measured and evaluated HELOS/R results.

HELOS/R + Range Combination - the Optimum Choice for Geological Samples

Geological samples for soil and sediment analysis often exhibit a very wide size distribution, which can be successfully measured with the HELOS/R series using the range combination option. The range combination has been evaluated as the ideal solution to provide unattended and reliable high resolution information in very short time cycles. The scientists of the Earth Sciences Laboratory at the Faculty of Earth and Life Sciences of Vrije Universiteit (VU) Amsterdam have experienced the HELOS/R-series with Range Combination over a period of six months now. One of their research subjects is to determine the effect of climate change on the environment. For this purpose they have to run thousands of wet soil samples every year.

Laser diffraction instrument HELOS/KR & QUIXEL in the Earth Sciences Laboratory at VU Amsterdam

The HELOS/KR laser diffraction sensor in combination with the suspension dispersing system QUIXEL, covering a particle size range from 0.1 – 3500 micron, was their optimum choice for fast and statistically reliable measurements.

Dynamic Image Analysis for Geological Samples at the Earth and Life Sciences Laboratory of Vrije Universiteit Amsterdam

The Sympatec QICPIC Dynamic Image Analysis instrument in the Earth Sciences Laboratory at VU Amsterdam

For new research projects in soil characterisation, information on the particle size distribution need to be enhanced with information on the particle shape. With Sympatec’s Dynamic Image Analysis instrument QICPIC, the scientists of the Earth Sciences Laboratory at the Faculty of Earth and Life Sciences of VU Amsterdam have found the ideal tool for the concurrent investigation of the shape and size distribution of the particles.This instrument covers a size and shape range between 1µm and 20mm. It can be equipped with dry and wet dispersing modules. Due to the high speed image acquisition rate of 450 frames per second, samples in liquids and dry powders can be run at statistically relevant particle numbers of more than one million in less than one minute.

Numerous particle size and shape parameters can easily be determined and adapted to this special application.

Excellent Traceablity with Lattice Fence Distributions

Sympatec GmbH has proposed a new type of standard reference material (SRM) for primary validation of laser diffraction and image analysis instruments.

A lattice fence distribution covering one decade in particle size composed from 7 (log.) equally spaced spherical monodisperse materials.

For the first time this SRM uses a lattice fence distribution composed from a mixture of precisely qualified spherical, monodisperse materials. It enables much better precision in size and quantity than before independent of the width of the distribution.

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News Validated Mie Evaluation covers Particle Sizes from 1 nm to 10 mm

100 years after the introduction of the fundamental light scattering theory by Gustav Mie, a German physicist, Sympatec GmbH has introduced a new Mie code for its laser diffraction (LD) and photon cross correlation (PCCS) instruments. For the first time this code covers a size range from below 1nm up to 10mm and has been validated with a new extreme precision analysis by applying more than 40.000 precisely calculated data sets for verification.

This code is available for the WINDOX software versions 5.4.1 for PCCS and 5.4.2 for LD, or higher.

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Non-spherical Reference Materials Traceable to the Standard Metre?

Sympatec GmbH has recently published an investigation on non-spherical reference materials comparing the results of laser diffraction and dynamic image analysis. An excellent agreement is obtained even for non-spherical material, if both methods are using the same disperser. The image data of QICPIC have been converted to an equivalent laser diffraction signal by 2D Fourier transformations. Both systems have been set-up using first principles without using a particle size standard for calibration.

This method could be used in the near future to migrate image analysis results to laser diffraction results even for non-spherical particles at high precision.

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