ASTM E1772-95

It is important to recognize that the results obtained by this test method or any other test method for particle size determination using different physical principles may disagree. The results are strongly influenced by physical principles used by each method of particle size analysis. The results of any particle sizing method should be used only in a relative sense and should not be regarded as absolute when comparing results obtained by other methods.

Both sellers and purchasers of chromatography media will find the test method useful if mutually acceptable to all parties concerned to determine the particle size distributions for materials specifications, manufacturing control, and development and research.

1.1 This test method is valuable for the measurement of particle size and covers determination of the particle size distribution of chromatography media in the overall size range of approximately 1 to 450 &#956m using the electric sensing zone (ESZ) apparatus. This instrument uses an electric current path of small dimensions that is modulated by individual particle passage through an aperture and produces individual pulses of amplitude proportional to the particle volume (1).²

1.2 The values stated in SI units are to be regarded as the standard.

1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.