SF6 Gas and Oxygen Online Monitoring and Alarm System

SF6 Gas and Oxygen Online Monitoring and Alarm System
SF6 Gas Concentration Alarm Point: 100～1500×10⁻⁶(v/v)
SF6 Gas Detection Sensitivity: ±5% of Set Value
Oxygen Detection Concentration: 1～25% (with Digital Display Function)
Oxygen Concentration Alarm Point: 18%
Oxygen Measurement Accuracy: <0.5% (0.4% when O₂ is at 21%)
Temperature Display Range: -40～60℃
Humidity Display Range: 0～99%RH
Input Power: 176～265V AC
Alarm Output Point Power: 2A
Fan Output Contact Power: 380VAC 40A
Fan Ventilation Time Setting: 15MIN/time
Data Recording Time: 2 Years
The Indoor SF6 Gas and Oxygen Online Monitoring and Alarm System is an online monitoring and alarm system designed for detecting SF6 insulating gas leakage in new unmanned substation indoor SF6 combined electrical equipment.
This system uses imported new high-sensitivity SF6-O2 sensors, as well as temperature and humidity sensors. When there is a slight change in the concentration of indoor SF6 and O2, the sensor immediately responds to this change, effectively monitoring even at SF6 concentrations as low as 100ppm (v/v). The sensor converts the monitored SF6 concentration change into a resistance ratio, which is then amplified and processed through an anti-interference network. The signal is converted into a digital signal by a 16-bit high-precision A/D converter and sent to a single-chip computer. The single-chip computer analyzes and processes the signal, performs zero tracking, and transmits the results to the main controller via a 485 bus module. The main controller handles data processing, storage, color display, alarm triggering, fan control, and sends the results to a remote computer.
This equipment is designed based on the Fieldbus Control System (FCS) model. In this system, each transmitter and actuator is an intelligent instrument equipped with a CPU as the processor, capable of performing various functions such as data acquisition, control operations, and fault diagnosis. The basic structure of the fieldbus is shown in the figure below. Since each sensor is equipped with a CPU, the calibration of the sensors is more user-friendly and easier to operate.