A gas pycnometer operates by detecting the pressure change resulting from displacement of gas by a solid object. Expanding a quantity of gas at known pressure into an empty chamber and measuring the pressure establishes a baseline. Then a sample is placed in the chamber and the chamber is resealed. The same quantity of gas at the same pressure is again expanded into the sample chamber, and the pressure is measured. The difference in the two pressure combined with the known volume of the empty sample chamber allows the volume of the sample to be determined by way of the gas law. The accuracy and precision of the gas pycnometer in determining density is good, but the method relies greatly on the cleanliness of the sample material and purity of the analysis gas. In this case, Gold APP Instruments had explored a smart sample preparation degasser for materials handle, can guarantee to gain the "cleanliness" testing data.
