The invention relates to a method for measuring the
specific heat ratio of air by the vibration of a
piston in a cylinder. The method comprises the steps of connecting the two ends of a horizontally arranged transparent cylinder with gas containers respectively, forming an air hole which can be sealed in the outer side of each gas container, and arranging a horizontal bubble in the cylinder; unscrewing the gas containers respectively arranged at the two ends of the cylinder, plugging a
piston body into the opening end of the cylinder, and overlapping the center of the
piston body and the center of the cylinder; then, screwing the gas containers respectively arranged at the two ends of the cylinder, then screwing sealing caps respectively arranged at the outer sides of the gas containers at the two ends of the cylinder, turning on a power supply of a piece of
electromagnet arranged at the outer side of the cylinder so as to move the piston body by the
magnetic field, and
cutting off the power supply to enable the piston body to vibrate under the elasticity of air. The
specific heat ratio gamma of air is equal to 2mV / (r4T2P), wherein m is the
mass of the piston body, r is the internal
radius of the cylinder, V is the volume of the single-side sealed air, T is period of vibration, and P is
atmospheric pressure value of the outside air. The method has the beneficial effects that the sealed air has good elasticity, the experiment principle is precise, a strict
harmonic vibration is realized, the structure is simple, and the cost is low.