Abstract: The present disclosure is an optical line test system that detects a distribution of loss points of an optical line in a longitudinal direction, using a coherent light measurement device, applies vibration to facility disposed on a path of the optical line, detects a vibration point of the optical line in a longitudinal direction upon applying the vibration, using the coherent light measurement device, and identifies the loss point based on correspondence between the detected loss point and vibration point.

Abstract: An electrical device having a power generating element which includes a positive electrode containing a positive electrode active material, a negative electrode containing a negative electrode active material, and a separator, in which the coating amount of a negative electrode active material layer is set at 4 to 11 mg/cm2, the negative electrode active material represented by Formula (1), the positive electrode active material represented by Formula (2), and in that case, as a solid solution positive electrode active material to be contained in a positive electrode active material layer, a material represented by Formula (3) and having a particle surface that is provided with a certain amount of coating layer which is formed of an oxide or complex oxide of a metal that is selected from the group consisting of Al, Zr and Ti is used.

Abstract: Provided is a means which is capable of achieving satisfactory rate characteristics, while sufficiently making use of a high capacity that is a characteristic of a solid solution positive electrode active material in an electrical device such as a lithium ion secondary battery having a positive electrode which uses a solid solution positive electrode active material.