The present application provides a self-diagnostic gas density relay and a use method thereof, the gas density relay includes a gas density relay body, a gas density detection sensor, at least one diagnostic sensor, and an intelligent control unit; where the diagnostic sensor is configured to acquire deformation quantities of components that generate deformations, and/or positions or displacement quantities of components that generate displacements when the pressure changes, or the temperature changes, or the gas density changes in the gas density relay body; and the intelligent control unit is respectively connected with the gas density detection sensor and the diagnostic sensor, receives data acquired by the gas density detection sensor and/or the diagnostic sensor, and diagnoses a current working state of the gas density relay body. The present application is used for monitoring a gas density of the gas-insulated or arc-extinguished electrical equipment, and at the same time, on-line self-inspection for the gas density relay is completed, so that efficiency is increased, no maintenance is realized, operation and maintenance costs are greatly reduced, and safe operation of a power grid is guaranteed.

A detector that detects an alarm and/or fault condition with respect to a pressure of a medium is provided. The detector comprises a housing comprising an access tube configured to receive a medium and a bellows fixed to the housing comprising a cavity and a first contact surface. The detector also comprises an adjustment screw positioned within the cavity of the bellows, coupled to the housing via an insulation member, and comprising a second contact surface. The detector is further configured to detect a change in pressure of the medium based on whether the first contact surface and the first contact surface are in electrical communication.

The application provides a gas density relay with online self-check function and its check method, which are used for high voltage and medium-voltage electrical equipment. The gas density relay includes a gas density relay body, a first pressure sensor, a temperature sensor, a force measuring sensor, a driving contact action mechanism and an intelligent control unit. The driving contact action mechanism is configured to directly or indirectly drive the signal action mechanism of the gas density relay body to displacement, so that the gas density relay body will have contact signal action. The intelligent control unit will detect the alarm and/or blocking contact signal action value and/or return value of the gas density relay body according to the density value when the contact acts. Checking the gas density relay can be completed without maintainer coming to the site, which improves the reliability of the power grid, improves the efficiency, reduces the operation and maintenance cost, and can implement the maintenance free of the gas density relay.

The application provides a gas density relay with online self-check function and its check method, which are used for high voltage and medium-voltage electrical equipment. The gas density relay includes a gas density relay body, a first pressure sensor, a temperature sensor, a force measuring sensor, a driving contact action mechanism and an intelligent control unit. The driving contact action mechanism is configured to directly or indirectly drive the signal action mechanism of the gas density relay body to displacement, so that the gas density relay body will have contact signal action. The intelligent control unit will detect the alarm and/or blocking contact signal action value and/or return value of the gas density relay body according to the density value when the contact acts. Checking the gas density relay can be completed without maintainer coming to the site, which improves the reliability of the power grid, improves the efficiency, reduces the operation and maintenance cost, and can implement the maintenance free of the gas density relay.