HF-W-701 Sf6 Gas Density Monitor

Product Introduction

The SF₆ Gas Leakage Alarm and Monitoring System (hereinafter referred to as the System), equipped with the SF6 Gas Density Monitor, is a customized intelligent online monitoring system specially designed and developed to protect the personal health and safety of on-site staff working indoors with SF₆-containing equipment, in response to the power industry’s strict requirements for safe production. The physical product is shown in Figure 1.

Technical Features

1. High-precision Real-time Detection Powered by ARM Cortex™-M4 MCU, it integrates ultrasonic velocity and phase measurement to quantify SF₆ concentration online, breaking the qualitative-only limitation of traditional detection means.
2. Tailorable Hardware & Software The multi-functional main unit supports flexible function trimming via simple setup, matching different usage scenarios and cutting customer costs.
3. Ultra-low False Alarms Full differential signal processing eliminates disturbances from airflow and temperature & humidity changes, greatly improving system stability.
4. High-performance Processing System Top-down modular design delivers high execution efficiency, strong anti-interference and outstanding reliability and data processing ability.
5. Multi-parameter Monitoring Detects SF₆ leakage and oxygen shortage alongside ambient temperature and humidity, fully compliant with electrical safety operation codes.
6. Diversified Communication Interfaces Dual RS485 and CAN ports support single/multi-host networking with multiple sensors to fit various project architectures.
7. Data Recording & Export Large-capacity storage enables query of historical data, alarms and fan logs, with one-click export to USB for analysis and maintenance.
8. Extended Sensor Lifespan Intermittent working mode for SF₆ sensors enhances stability and service life effectively.
9. Intuitive Human-Machine Interaction LCD touchscreen displays real-time and historical data, and supports parameter configuration and manual fan control. A voice reminder automatically prompts nearby staff within 3 meters and judges site access safety.
10. Excellent Anti-interference Performance Optimized hardware and software anti-interference design ensures steady operation and precise measuring data.

Main Functions

Function Category	Detailed Function Description
Basic Environmental Detection Functions	1. Detect SF₆ gas concentration in the environment 2. Detect oxygen concentration in the environment 3. Detect ambient temperature and humidity
Real-time Monitoring & Display Functions	1. Real-time display of telemetry and telesignal data from all monitoring points 2. Real-time display of alarm messages from all monitoring points
Alarm Related Functions	1. Trigger alarms for excessive SF₆ concentration and oxygen deficiency 2. Audible, visual and voice alarm output 3. Remote alarm notification 4. Storage and recording of all alarm records
Exhaust Control Functions	1. Forced ventilation when oxygen is insufficient or SF₆ concentration exceeds the limit 2. Automatic fan startup upon alarm activation 3. Timed automatic ventilation 4. Manual forced start or shutdown of all fans
Data Management Functions	1. Query, display and storage of historical data 2. Export of all historical records 3. Query and display of historical trend curves for telemetry values
System Configuration & Human-machine Interaction Functions	1. Protection setting parameter configuration 2. Automatic voice broadcast of on-site environmental status when personnel enter the GIS room 3. Human body infrared induction detection
Networking & Data Transmission Functions	1. Support configuration of multiple monitoring points in separate zones 2. Multi-point networking, with communication protocols available for docking with substation background database 3. Remote data transmission

Technical Parameters

Parameter Category	Specific Parameter Description
Operating Voltage	AC/DC 220V±10%, 50Hz
Power Consumption	<10W at rated voltage
Accuracy Class	Class 2.5
SF₆ Gas Concentration Measurement	Measurement range: 0-3000ppm; Over-limit alarm point: 1000ppm (national standard value), accuracy: <5% FS
Oxygen Content Detection	Detection range: 0-30%; Oxygen deficiency alarm point: 18% (national standard value), accuracy: <1% FS
Temperature Detection	Detection range: -30 — +99℃; Accuracy: ±0.5℃
Humidity Detection	Detection range: 10-99% RH; Accuracy: ±0.5%RH
Fan Output Power Contact	2A
Remote Communication Method	485/Ethernet
Overall Dimensions	On-site main unit: L340×W250×H73mm; SF₆ and oxygen detection unit: L160×W120×H38mm; Temperature and humidity detection unit: L100×W120×H38mm
Historical Monitoring Data Storage	5 million entries
Touch Display Screen	7 inches
Installation Method	Both the main unit and detection units are wall-mounted
Working Environment	Temperature: -25℃～70℃; Humidity: ≤95%
Electromagnetic Compatibility (GB/T 17626)	1. Electrostatic Discharge: Level 4 2. Radiated Immunity to Radio Frequency Electromagnetic Fields: Level 4 3. Immunity to Electrical Fast Transient Bursts: Level 4 4. Surge (Impact) Immunity: Level 4 5. Conducted Immunity Induced by Radio Frequency Fields: Level 4 6. Power Frequency Magnetic Field Immunity: Level 4 7. Pulse Magnetic Field Immunity: Level 4 8. Damped Oscillatory Magnetic Field Immunity: Level 4 9. Immunity to Voltage Dips and Short Interruptions: 60% UT, duration 10 cycles
Mechanical Performance (GB/T 11287, GB/T 14573)	1. Vibration Response: Level 1 2. Vibration Endurance: Level 1 3. Shock Response: Level 1 4. Shock Endurance: Level 1 5. Bump: Level 1

Wiring of SF₆ Gas Leakage Monitoring System

FAQ

Q1: What is the core function of the SF6 Gas Density Monitor?

A1: It adopts temperature compensation to monitor real-time SF6 gas density inside HV equipment, and triggers alarm & interlock protection when density is insufficient to avoid insulation and arc-extinguishing failure.

Q2: Why does this monitor need temperature compensation?

A2: SF6 pressure changes with ambient temperature. The module converts pressure into standard density value to eliminate temperature interference and ensure accurate measurement.

Q3: What signals will the SF6 Gas Density Monitor output?

A3: It provides low-density alarm signal and lockout signal to interlock the switchgear’s opening/closing circuit and prevent misoperation.

Q4: Which devices is the SF6 Gas Density Monitor applicable to?

A4: It is widely matched with GIS, circuit breakers, ring main units and other high-voltage switchgear filled with SF6 insulating gas.

Q5: What problems can this monitor help detect?

A5: It effectively identifies slow gas leakage from equipment shell, sealing parts and joints, realizing early fault warning before obvious pressure drop occurs.

Q6: Is regular calibration required for the SF6 Gas Density Monitor?

A6: Yes. Periodic on-site calibration is recommended according to power industry standards to guarantee long-term measuring precision and reliable protection action.