Single Particle Optical Sizing

The AccuSizer 780 uses the method of single-particle optical sizing (SPOS) to quickly count and size a large number of particles, one at a time, thus constructing the true particle size distribution (PSD). This approach is in sharp contrast to "ensemble" methods, such as laser diffraction and sedimentation, which must process information produced simultaneously by many particles. These alternative techniques require the use of complex mathematical algorithms to invert the data and yield only rough approximations of the PSD, with limited accuracy and very poor resolution. The AccuSizer determines PSDs with resolution and accuracy comparable to those produced by the classical resistive-pore, or electrozone, method. The 780 does not miss the "details", which are often critically important in determining the quality of many products. A wider size range, higher count rate, compatibility with any liquid or gas, and relative immunity to clogging make it an instrument in a class all its own.

The SPOS particle sizing method requires that concentrated suspensions be diluted, in order to eliminate particle coincidences in the sensing photozone. Excessive dilution results in too low a count rate and poor statistical accuracy of the PSD, while overly concentrated suspensions produce distortions in the distribution. The AccuSizer 780 uses AutodilutionPat, which quickly and automatically dilutes the starting sample to the optimum concentration, resulting in efficient and accurate analysis. Trial-and-error manual dilution is eliminated, paving the way for single-keystroke operation; a complete analysis and flush cycle can be completed in less than 3 minutes.

The 780*s single particle sensitivity detects the important features in the size distribution which other techniques usually miss. Single particle optical sensing makes the measurement accurate, while AutodilutionPat and leading-edge electronics make it fast and easy to use. Trading off accuracy and resolution for speed and ease of use no longer have to be made with the AccuSizer 780.

The AccuSizer 780 delivers reliable size and count data for even the largest particles.A few outliers can spell the difference between product success and failure; however traditional laser diffraction particle size analyzers cannot detect large particle outliers in a sea of smaller particles.The AccuSizer 780 reveals particle size differences that previously went unnoticed.The 780 is a stable, sensitive instrument that uses Single Particle Optical Sizing (SPOS) to count and size particles one at a time, eliminating missed particles while allowing:

• Particle sensitivity of 10 PPT

• Particle size accuracy of 2%

• Particle count accuracy of 10%

Recently,an independent study proved that SPOS analyzers were 1,500 to 25,000 times more sensitive in detecting outliers than light scattering and accoustical sizing instruments.

The AccuSizer 780 can also resolve fine particle distributions that are directly related to the materials' properties. It is a proven and valuable tool that laboratories around the world are already using to reformulate their product lines from R&D to production.

A modular solution to meet your most challenging applications

The AccuSizer 780 AD Autodiluter is the cornerstone of the modular family of instruments. The AccuSizer 780 AD incorporates a series of wide dynamic range sensors with a single stage exponential diluter to provide a flexible high resolution, accurate, sensitive particle sizer. It provides particle size information with unprecedented resolution and accuracy. It is especially suited to providing information on particle size distributions (PSDs) that are on scale but is not limited in the statistical information that it can provide on tails of mostly submicron distributions. This patented module eliminates the need for manual dilution of concentrated samples. Autodilution makes particle size analysis quick and easy, with no training required. Results are highly reproducible.

AccuSizer 780/APS Automatic Particle Sizer

The APS has been called the bolder detector by many of our customers because of its ability to detect low levels of aggregates several standard deviations away from the mean of the distribution. Often these aggregates are the difference between a good and bad sample. One independent study showed the APS was 1,500 to 25,000 times more sensitive in seeing outliers in the CMP slurry than commonly used laser light scattering and acoustical sizing instruments. The same sensitivity will apply to other applications such as inks, pigments, drug emulsions where a few large particles spell the difference between success and disaster.

AccuSizer FX Focused Extinction

The AccuSizer FX is a new breed of particle size monitoring system designed to go from the R&D lab to the process line with minimum system reconfiguration. The FX utilizes a patented focused beam technology that allows the sensor to focus on a specific area of the flow channel to count and size individual particles at concentration levels that are hundreds of times higher than traditional sensors. Although this type of approach has been tried by other techniques it has been plagued by low resolution and accuracy. The new FX sensor technology utilizes a patented electro-optical configuration that maintains the same levels of resolution and accuracy found in traditional SPOS sensors.

The AccuSizer 780/LVS Large Volume Sizer

The AccuSizer 780/LVS Large Volume Sizer is specifically designed to analyze large volumes of liquid with particles as large as 2000 microns. Often it is imperative to pass large amounts of diluted dispersion through an SPOS sensor. The key to the AccuSizer LVS system is its large volume dilution chamber that combines the ease of use of autodilution with the speed of a quick flushing fluidics system.
The AccuSizer 780/LVS allows the user to introduce a spoon full of material into the large volume dilution chamber and immediately start taking data. Ease of use of a fully automated dilution system is combined with SPOS to provide fast, high resolution, high sensitivity particle size distributions.

AccuSizer 780/SIS Syringe Injection Sampler

When volumetric sampling is paramount, the SIS sampler fits the bill. With syringes ranging from 0.5 to 25 ml and a precision stepper motor with over 25000 steps per pull the SIS sampler is a perfect addition to the family of modular instruments. It is specifically suited to applications in the pharmaceutical industry such as USP <788> small and large volume injectables. Now available for use with the AccuSizer 780/SIS is 21 CFR Part 11 compliant software, Calibration and Validation SOPs.

AccuSizer 780/OL Online

Our patented Autodilution technology has allowed us to take our laboratory instrumentation known for high precision, accuracy, resolution and reproducibility,ａnd carry it to the

process line. Simple customizable computer controlled fluid-sampling devices are used to grab a precise aliquot of concentrated in-line dispersion and automatically inject it into the Autodilution system. Then, just as in our laboratory systems, the sample is diluted to the optimal concentration for an SPOS measurement, without regard to its initial concentration or particle size distribution (PSD). The resulting PSDs, with unique single particle resolution are identical to those that historically could only be obtained in the research laboratory. No longer must correlation algorithms and complex statistical tools be developed to compare laboratory findings with online results.

The Autodilution module is an integral part of both of our laboratory instruments- the AccuSizer 780 Single Particle Optical Sizer and the Nicomp 380 Submicron Particle Sizer. These laboratory instruments have been modified to meet the rigors imposed by online process monitoring. They have been redesigned utilizing ruggedized com-ponents and are housed in different classes of NEMA enclosures, depending on the application. These vary from dust and waterproof enclosures to explosion-proof modules that can handle even the most aggressive environments, including high pressures and sub-zero temperatures.

Multi-port systems are available with specialized software to monitor multiple points in an online process. These reduce costs while maximizing coverage to ensure that quality control requirements are met. Users have a choice of using either an embedded mode Windows based controller or a Programmed Logic Controller (PLC) which are often found in process control systems. In either case the resulting data can be displayed on screen or passed to a Laboratory Information Management System (LIMS) as an ASCII file. It provides for limitless posbcapture data analysis that can easily be customized by the user with common programs found on all modern computer systems.

The AccuSizer 780/OL system is able to detect minute amounts of oversized particles in the tail of the process dispersion. It has produced results where the difference between a good and bad sample is determined by a few hundredths percent in volume fraction above a particular critical particle diameter, several standard deviations above the main peak of the distribution. It is also able to detect very small percentages of “fines” in the presence of larger particles. These fines often play an important role in determining the viscosity, flowability and other characteristics of both the process dispersion and the final product.