The GeoPyc 1360 measures envelope density using a non-toxic, non-destructive volume displacement technique. It can also measure a density comparable to what is usually termed as tap density. The latter can be defined as the mass of a material that, upon packing in a precisely specified manner, fills a container to a specified volume, divided by the container volume. Traditional methods of determining tap density involve repeatedly lifting and dropping a container of sample to tap down the volume and pack the particles. The T.A.P.™ (Transverse Axial Pressure) density option can be purchased for the GeoPyc 1360. With this option, the GeoPyc accomplishes essentially the same measurement as a tap density device. It rapidly measures the bulk volume and calculates the bulk density of granular and powdered samples under a wide range of compaction conditions. Tap density (as usually measured) is bulk density determined at one specific set of conditions.
The T.A.P. analysis method is essentially noiseless, rapid, and easy to perform. First, a determination of the volume of an empty sample chamber is made and the data stored in the GeoPyc for repeated use during subsequent sample analysis. Next, a weighed quantity of sample is placed in the sample chamber and a plunger is inserted partially into the chamber. The chamber/plunger assembly is mounted on the instrument. The desired consolidation force (force with which the sample is compressed in either force [Newtons] or pressure [Newtons/cm2]), sample weight, and other parameters are entered and analysis begins. The operator has complete control over the degree of packing achieved during analysis.
The plunger exerts the consolidation force in stages. The plunger retracts a short distance, the sample is agitated, and then the plunger moves forward again until the desired force is reached and a measurement of the sample volume is made. Then the plunger retracts slightly. This is called the consolidation cycle. The force required to move the plunger into the sample chamber is detected by a force transducer, which ensures that the plunger exerts a consistent force upon the sample.
After the consolidation cycles are completed, the instrument uses the stored data to calculate the results. The measurement that the GeoPyc delivers is precise, with accuracy and reproducibility typically better than ±1%. Correlation of the results from the GeoPyc with those obtained using the older tap density method can be obtained by determining the degree of packing the other method achieved.
The GeoPyc T.A.P. Density Option has the ability to obtain precise results comparable to traditional tap density measurements, and is ideal for obtaining the packing densities of powder and bulk materials
Literature:
GeoPyc 1360 TAP Density Brochure