The Principle of Reproducibility of A Particle Size Analyzer
The "reproducibility" of a Laser Particle Size Analyzer is an important indicator to determine the measurement result and instrument performance. Repeatability of particle size measurement result refers to the deviation between the average value and the result, under the same conditions, the same instrument, and the same operator. Good repeatability in a laser particle size analyzer represent the accuracy of the instrument, as well as the reliability.
The performance of a laser particle size analyzer must comply with the international standard ISO13320: 2009. The repeatability error from the cumulative statistics which is presented by three particle size distribution percentage values, D10, D50, and D90. The allowable error has to be better than 5%, 3%, 5%.
Distribution of Particles
A superior Laser Particle Size Analyzer must be designed by different factors to improve the repeatability of the measurement results. Here are some key factors for your reference:
De-agglomeration
Generally, using ultrasonic to pre-disperse the powder sample in liquid suspension for 3 to 5 minutes, while adding dispersant and stirring. To those ultra-fine samples, it is better to extend the dispersing up to 10 minutes.
Liquid Selection
To those powder samples which are clumped together may require sample preparation. Mix and stir the powder sample in liquid suspension results indicative of the size distribution of the individual particles. Choose the liquid which will not dissolve nor swell the sample is necessary. The common liquid is usually water or ethanol. If there is no proper liquid for your sample, you can choose dry method for particle size measurement. Sometimes comparing the wet versus dry results can find out optimal dispersing conditions.
Hardware & Software
The instrument's light source, signal transmission system, software parameters & settings, data processing methods, cleanliness of sample cell, focusing, and other instrument factors, can influence the repeatability, too. Ensure the good HW & SW conditions on an instrument is important.
Environment
In a high humidity environment leads a foggy window. And if there are sources of electromagnetic, vibration, direct light, or other interference sources around the instrument, may influence the repeatability. Besides, the stability of input voltage of the instrument will also affect the repeatability.
Sample
The instability of the sample itself, such as dissolution, agglomeration, may also affect the repeatability of the particle size testing.
Shading
Shading is caused by the absorption of the sample, after light source passed through it. The degree of absorption by the sample is typically represented by the equation, (I0-Ii) / I0 × 100%. I0 is the intensity of the light, passing through the pure liquid suspension. And Ii is the intensity of the light, passing through the sample mixed liquid. An over-shaded sample will aggravate the multiple scattering phenomenon of the particles. However, a too little shaded liquid sample will affect the representativeness, and will reduce the signal-to-noise ratio, which will affect the repeatability, too.
The Calculation of Shading Percentage
Precipitation: The larger or heavier particles may precipitate in the circulation pipeline and results the measurement of particle size getting smaller and smaller and further influence the repeatability. This phenomenon is related to the design of the path of pipeline, and the path of sample flow, as well as the design of the efficiency of mechanism.
Those Particle Size Analyzer manufacturers are doing their best and insert better design ideas and method to improve the above major factors, which influence the performance of the instrument, and enhance the precision.
ACTTR Technology selects the best fitting Laser Particle Analyzer for you among various brands, and brought to you the best price-performance instrument to find your requirement and helps to create a highest value.
Bettersize, a professional Laser Particle Analyzer manufacturer, developed a full range of particle size analyzer products. The repeatability can achieve 1/5 or 1/10 of the errors which are defined by the internal standards, and the repeatability is ideally better than 1%, and typically better than 0.5%. There are numbers of patented related to the improvement of precision, automation, user interface, and shows you unprecedented excellent experiences. To learn more about the advantage of Bettersize's full range of Laser Particle Size Analyzers, please visit ACTTR Technology "Laser Particle Size Analyzer" Product Page. Or "Contact ACTTR" for more detailed information.