Overview
The ppm-level and percentage-level (%) SF6 (Sulfur Hexafluoride) infrared gas analyzers utilize high-precision Non-Dispersive Infrared (NDIR) technology. The ppm-level analyzer is heavily deployed in high-voltage substation switchgear rooms and cable trenches for early-stage environmental leak detection and personnel safety monitoring. Meanwhile, the percentage-level (%) analyzer specializes in measuring SF6 insulation purity inside Gas-Insulated Switchgear (GIS) compartments, diagnosing internal arcing degradation, tracking chemical purity during manufacturing, and managing process gas ratios in semiconductor plasma etching.
Principle
Various polyatomic gases (CO, CO2, CH4, etc.) absorb infrared light not the whole band, but only a part of the band, which are called characteristic absorption bands. Different gases have different infrared absorption wavelengths. Infrared photometry analyzer is based on the characteristic of selective absorption of infrared radiation at different wavelengths of certain gases. When infrared light pass through a gas mixture, the measured component of the gas absorbs the infrared radiation energy, according to the Lambert-Beer absorption law, the concentration of a gas can be determined from the change in light intensity.
Application
• High-Voltage Substation Environmental Safety [ppm Range]
GIS Room Leakage Monitoring: Distributed online multi-point ambient monitoring in high-voltage and ultra-high-voltage (HV/UHV) indoor GIS switchgear rooms to detect trace SF6 leaks from flange gaskets or valve seals early.
Oxygen Displacement & Oxygen Safety: Preventing asphyxiation and protecting utility personnel entering enclosed areas or cable basements, as heavy SF6 leaks can settle down and displace breathable oxygen.
Fugitive Greenhouse Gas Control: Tracking micro-leaks to minimize emissions of SF6, satisfying global strict greenhouse gas regulatory compliance and reduction goals.
• Power Grid Asset Management & GIS Maintenance [Percentage % Range]
SF6 Insulation Purity Verification: On-site or continuous measurement of gas purity (typically targeting >97% to 99%) inside high-voltage circuit breakers and transformers to ensure maximum dielectric strength and arc-quenching performance.
Gas Decomposition Diagnostics: Monitoring pure SF6 concentration trends alongside decomposition byproducts (like SO2 or HF) to analyze inner compartment arcing severity and determine maintenance intervals.
Top-up Cylinder Verification: Quality control of SF6 recycling and reclamation equipment during evacuation and re-filling cycles of electrical equipment.
• Semiconductor & Flat-Panel Display Manufacturing [Percentage % Range]
Plasma Etching Process Control: Precise monitoring of the feed gas flow concentration and mixture stability of SF6 used as a fluorine source for deep silicon plasma etching (e.g., Bosch process for MEMS and TSV).
CVD Chamber Clean Verification: Analyzing exhaust headers to confirm complete tool cleaning or tracking SF6 utilization inside chemical vapor deposition (CVD) equipment.
• Industrial Component Leak Testing [ppm Range]
Tracer Gas Leak Detection: Utilizing SF6 as an effective tracer gas for industrial leak test stations (such as testing high-end fire extinguishers, luxury car alloy wheel hubs, or waterproof electronics enclosure lines) due to its unique NDIR signature and chemically inert properties.
Measurement components and ranges
• SF6: 0 ~ 50ppm up to 100%(Vol)
For detailed introduction, please refer to Infrared photometry analyzer.