| 摘要 |
According to the present invention, a level member is provided. The level member comprises: a level member main body; one or more transparent tubes installed in the level member main body and containing bubbles and a liquid; a non-conductive plate which is installed in the level main body and has a first to a fourth pair of electrodes on the inner circumferential surface of an internal space penetrating the non-conductive plate; a conductive disk capable of electrically connecting one pair among the first to the fourth pair of electrodes along a rolling position on the inner circumferential surface of the internal space; and one or more laser oscillation devices installed in the level member main body to irradiate laser light when one pair of electrodes among the first pair to the fourth pair of electrodes are electrically connected. |
