Quantachrome Instruments Stereopycnometer and Multipycnometer

The [b]Stereopycnometer[/b] is the standard model of the series of manually operated pycnometers. It offers a choice of two interchangeable sample cells used in conjunction with a single reference volume. A sample is placed in the sample cell and degassed by purging with a flow of dry gas, by vacuum, or by a series of pressurization cycles. The analysis is performed by pressurizing the sample cell to approximately 17 psi and recording the value. The selector valve is rotated so the gas expands into the reference or added volume and that lower pressure is recorded. From these two readings the sample volume can be quickly and accurately calculated. If samples are compressible foams, the cell-to-reference pressure sequence of the Stereopycnometer is the preferred method over that employed by the Multipycnometer. The [b]Multipycnometer[/b] is the most versatile model. It gains its name from its multiple volume feature that offers three sizes of interchangeable sample cells: 135 cc, 20 cc, and 4.5 cc. In addition, there are three different calibrated reference volumes which provide peak performance for each cell size. The operating sequence is reversed from that of the Stereopycnometer... pressurizing the reference volume first, then expanding the gas into the sample cell. The very wide operating range of the Multipycnometer offers the greatest sample size flexibility in the series, while still maintaining its high degree of accuracy.