Determination of Particle Density Using Air Pycnometer

Abstract

For the measurement of particle density, many types of devices have hitherto been proposed. Among them the air pycnometer method is found superior to the immersion-into-liquid method in that the measurement technique by the former is simpler, and in that it is applicable to soluble powders. There is drawback, however, in that it does not yield exact duplicate value.
The air pycnometer method can be classified into four types, i. e. there can be twofold classification into the constant volume method and the variable volume method, of twofold classification into the compressing method and the expansion method, as follows:
The constant volume method of the compressing method
The variable volume method of the compressing method
The constant volume method of the expansion method
The variable volume method of the expansion method
These four types of methods were applied to the measurement of several kinds of samples of powdered materials, in which newly designed apparatuses were used, and the results were compared with the measurement made with the immersion-into-liquid method.
It is concluded that the compressing method of constant volume has been found most preferable as possible of being easily constructed, and as yielding duplicate value, if measurement is made of the material at larger ratio of its sample volume to its total volume.