Abstract: An insulation diagnosis method according to the present invention includes: measurement step through which a signal generated at a diagnosis target device is measured; detection step through which a frequency or a frequency band manifesting a maximum amplitude signal strength is detected from the signal having been measured through the measurement step; and identification step through which an insulation defect type pertaining to an insulation defect having occurred in the diagnosis target device is identified based upon the frequency or the frequency band manifesting the maximum amplitude signal strength having been detected through the detection step.

Abstract: Partial discharge occurring in a continuously operated electric machine is monitored all the time. Even when the electric machine is mounted in mobility equipment, the partial discharge is monitored all the time.

Abstract: Disclosed is a method for producing a metal hydride, which enables to obtain a metal hydride from a metal imide or a metal amide. Specifically, in an air current containing a hydrogen gas having a hydrogen partial pressure of 0.1 MPa or greater, hydrogen is reacted with one or both of a metal imide and a metal amide, thereby producing a metal hydride. The metal constituting the metal amide and the metal imide is preferably lithium, sodium or potassium.