EVALUATION OF FINE CERAMICS RAW POWDERS WITH PARTICLE-SIZE ANALYZERS HAVING DIFFERENT MEASURING PRINCIPLE AND ITS PROBLEM

Many kinds of analyzers based on various principles have been developed for measuring particle size distribution of the ceramics powders, But the reproducibility of the results, interchangeability of the models, reliability of the ends of the measured distribution have not been investigated for each principle, In this paper, these important points for particle size analysis were clarified by measuring raw material powders of fine ceramics, (1) in the case of laser diffraction and scattering method, the reproducibility in the same model is good, however, interchangeability of the different models is not so good, especially at the ends of the distribution. Submicron powders having high refractive index show such a tendency remarkably, (2) the photo sedimentation method has some problems to be conquered, especially in measuring submicron powders Having high refractive index or flaky shape particles, The reproducibility of X-ray sedimentation method is much better than that of photo sedimentation, (3) the light obscuration and electrical sensing zone methods, show good reproducibility, however, sometime bad interchangeability is affected by calibration and so on.