Abstract
As the scientific development advances, the measurements of density have been widely used in the water quality industry, the petroleum industry, the food industry, the wine industry, the pharmaceutical industry, the aerospace industry, and the semiconductor industry. However, most of densitometers used by industry in Taiwan are imported from foreign countries. In addition, densitometers used in the semiconductor industry are expensive. Consequently, this will add to the cost of related industries. By developing densitometers domestically, we can decrease the cost of production, and create new opportunities for our related industries.The theory and testing of a U-type vibration densitometer will be studied. The exciter will drive the U-type tube and keep it on a vibration state. When the tested fluid flows into the tube, the frequency of the vibration tube will be changed. The total mass will be increased when the fluid density increases and the frequency will be decreased. With calibration, the frequency and the density of the fluid can be correlated by some fixed relationship function. The vibration function will be the mathematical relationship between the density and the frequency. By measuring the frequency of the U-type tube, we will get the density of the tested liquid fluid. Generally, the frequency of the tested liquid is inversely proportional to the density. Experiments, analysis, and theories will be used to study densitometers in this paper.