| 摘要 |
According to the present invention, an instructional instrument for measuring the density of a gas comprises: a cylinder body having an inlet part at one side thereof, having an opening part at the other side thereof, and having a space capable of storing the gas therein through the inlet part, wherein the one side faces the other side; a piston housed in the cylinder body and moving in the cylinder body; and a fixing unit fixing the piston to be able to move in the cylinder body by the desire of a user. According to the present invention, the instructional instrument allows the piston to move in the cylinder body while the piston is thread-fastened to the cylinder body so that even a middle school student such as a weak person can easily measure the density of the gas. In addition, the piston can move in a thread mode so that: an error range is minimized by fixing the piston on a desired position; and the various densities can be measured by measuring any density within the capacity of the cylinder body. Furthermore, the instructional instrument has a simple structure and is easily manufactured so that: a user can use the instructional instrument economically and easily understand a principle in the density of the gas compared with an existing specialized instrument for measuring the density of the gas. |
