What Parameters Indicate the Performance of a Particle Size Analyzer?
Four main parameters are used to evaluate the performance of a particle size analyzer:
(1) Sensitivity: refers to the change in test results when two samples with very small size difference (e.g., D50 difference of 1μm) are measured.
(2) Resolution: it indicates the minimum value detected for the measured sample, when the specified error is in compliance with the normal distribution conditions, in a given confidence coefficient (usually take as 99.7%, sometimes 95%).
(3) Repeatability (also known as precision): refers to the result consistency when one sample is measured for multiple times.
(4) Accuracy: describes how close the average results (measured under certain conditions) is to the true value. The "true value" refers to the nominal value given on the certificate of the reference (standard) material. However, any sizing methods including the absolute sizing method have errors in the measurement results. Therefore, this ‘true value’ is only a relatively reliable approximation of the real value.