Abstract: The present invention relates to a system for decomposing harmful substances by using photocatalyst. The system for decomposing harmful substances by using photocatalyst of the present invention comprises a flow passage where a fluid containing harmful substances flows, a rotator having a photocatalyst fixed on surface thereof and installed in said flow passage in rotatable state, and photo-irradiation means for irradiating light to said photocatalyst. In the system, the photocatalyst fixed on the rotator in rotation is activated by the photo-irradiation means and decomposes harmful substances in the fluid, while the fluid is agitated by the rotation of the rotator.

Abstract: Abnormal conditions of a tank type gas circuit breaker are detected by driving a movable contact with a drive force and at a speed respectively lower than normal drive force and speed. Measuring units are mounted on various portions of a casing of the circuit breaker without disassembling the same and measured data are displayed for comparison.

Abstract: A method and apparatus for detecting an abnormal condition of a switch gear device including a switch gear, for instance a circuit breaker driven by an operating device. A device for detecting the operating force applied from the operating device to the circuit breaker is mounted between the operating device and the circuit breaker. Data is obtained from the detecting device, expanded in time for analysis, and compared with data obtained under a normal state to judge the presence or absence of an abnormal condition within the switch gear.