Simple pyknometers are best suited for measuring the density of non-aerated samples. Any materials which contain a significant volume of entrapped gas or air during manufacture can only be accurately measured using the 1510.
The Pressure Density Cup takes a fixed volume (100 cc) of the sample and compresses it so that any errors due to entrapped air or gas are eliminated. As air is more soluble at high pressures, it is believed that the entrapped air is lost by its dissolution into the test material. Any undissolved bubbles are then compressed to a fraction of their original size. By then weighing the pressurized sample, its true density may be calculated. Repeatability of this test is therefore very good. |