Digital density relay

Digital gas density meters are primarily used to control and monitor the density of SF6 gas in sealed enclosures, typically in gas-insulated equipment such as SF6 high-voltage switchgear. They employ bellows‑based gas compensation technology to achieve highly accurate density measurements. Equipped with multiple sets of microswitch contacts, they can transmit alarm signals via the secondary circuit when pressure reaches preset alarm, lockout, or overpressure thresholds. Additionally, these devices feature data communication capabilities, enabling real-time transmission of density and other parameters to a central backend system—either through wired or wireless links. The online monitoring backend leverages big‑data analytics to effectively assess trends in gas leakage and quantify leakage rates, allowing for the early detection of abnormal conditions.

Next-generation intelligent density relay with self-diagnostic functionality

During operation, conventional density relays are prone to performance degradation—such as reduced accuracy, mechanical jamming, and contact failure—posing significant safety risks. Consequently, they require periodic calibration; however, manual calibration is labor‑intensive and inefficient. The new generation of intelligent density relays, equipped with self‑diagnostic capabilities, features a highly integrated mechanical–digital module design. Embedded within the instrument is a self‑learning diagnostic data model, enabling real‑time sensing, monitoring and early warning, as well as analytical diagnostics. Via an intelligent control unit and a pressure‑adjustment unit, the actuation thresholds of mechanical alarms and lockout contacts can be calibrated online, ensuring maintenance‑free operation throughout the entire lifecycle and allowing fully autonomous, smart monitoring of the device.

Online Insulating Gas Monitoring System

The online insulation‑gas monitoring system uses sensors installed within gas compartments to continuously measure and track key parameters—such as temperature, pressure, density, and trace moisture—in the SF6 gas inside circuit breakers, GIS equipment, and other electrical devices, along with their trend changes. It automatically uploads this data to a backend system, enabling real-time monitoring of insulation‑gas density, moisture levels, and other critical variables. Users can flexibly configure alarm thresholds, query historical data locally, and accurately assess equipment leakage trends and leakage rates, thereby detecting potential abnormalities early and ensuring the safe operation of electrical equipment and the entire substation system. This solution truly realizes online monitoring for electrical equipment in substations and unattended stations.