DBP absorption number

Part 10 of ISO 787 gives a pycnometer method of density determination. Two methods are suggested. One method uses simple wet pycnometer in which the sample displaces water or some other liquid and the result is determined by a gravimetric method. The other method uses vacuum to remove air from the sample followed by the introduction of a portion of the liquid under vacuum. There is an inevitable difference in the results and the precision of each method. The differences in the determined values may also come from the choice of liquid used for displacement. 

Part 23 of ISO 787 contains a description of an alternative method which allows to remove air entrained in the sample of a powdered material. The powder is placed in a special tube, mixed with an excess of the displacement liquid more than sufficient to cover its surface, and placed in centrifuge to remove air. 

The change in a material s density caused by a filler addition can be measured by a method which relies on the change of weight of the material when immersed in a liquid (either water or other liquid). The method discussed here is fast and precise and it is suitable for the determination of density of filled materials. 

A Scott volumeter is suggested as being suitable for measuring the density of metal powders. The method gives a bulk density of the metal powder and results can be related to the measurement of tamped volume (see below). The Scott volumeter is more complex and precise than the ISO method. The result is given as apparent density. 

Methods of testing conductive materials are used to evaluate specimens containing conductive fillers. Two ASTM standards contain details of specimen testing for 

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