Research on a type of density measuring method for solids

Aiming at the disadvantages of contact measurement density instrument and the limitation of the detection range, this paper put forward a kind of noncontact measurement. By measuring the change of the air pressure of fixed container, this method indirectly obtains the volume of the non-hollow solid, and calculates the density of the solid. The extensive range is one of the notable advantages of the device. This device can do harmless measurement of the density of every non-hollow solid which has no chemical reaction with the air. Another advantage is that it avoids the single-drainage method, which may harm the experimental subjects, and the error of the consequence. Below the maximum pressure of the container, the device can add more air pressure by controlling the air compressor, thereby, to improve the accuracy of the measurement which can reach less than 3 percent.