The invention relates to an SF6 online
monitoring system, which comprises a pointer type SF6 gas density
relay, a three-way
pipe, a remote transmission module, a sensor module, a self-induction fan and a pipeline, wherein the pointer type SF6 gas density
relay is connected with a first interface of the three-way
pipe, the sensor module is arranged in the three-way
pipe, the sensor module is connected with the remote transmission module, the pointer type SF6 gas density
relay comprises a pressure gauge, the remote transmission module is installed on the pressure gauge, a second interface and a third interface of a three-way pipe are connected with a pipeline, one end of the pipeline is connected with a
transformer switch body, the other end of the pipeline is a
verification port, and a self-
inductance fan is arranged in the pipeline. The problem that detection errors are generated due to the fact that SF6 gas in the density relay does not circulate is solved, real-time detection of the full-period operation state of the high-
voltage equipment is achieved, and reliable operation of the high-
voltage equipment is guaranteed.