The SF6 density relays of Ningbo Houqing 220kV Substation and 220kV Yiting Substation have reached the required verification period according to the "DL/T 596 Preventive Test Regulations for Power Equipment". Our company, in conjunction with the customer's power outage maintenance, followed the specified items in the "Verification Regulations for Sulfur Hexafluoride Gas Density Relays" DLT 259-2012 to verify them, ensuring that the contact action accuracy, contact resistance, and insulation resistance of the density meter during operation meet the requirements of the regulations. We have replaced the data deviation meter