Rapidox SF6 multigas analyser

SF6 is a man-made gas used in high-voltage switchgear because of its great arc quenching capabilities. Partial discharges and leaks over time eventually cause the SF6 to decompose into highly corrosive compounds. It is therefore essential to monitor the condition of the SF6 to protect the equipment from spark damage and corrosion.

The Rapidox SF6 Multimeter is a multi-gas analyser for the simultaneous measurement of SF6 (0-100%), SO2 (0-100ppm) and H2O dew-point (-65+20°C). The analyser is designed for controlling and monitoring the quality of SF6 in gas insulated sub-stations and circuit breakers. The analyser not only measures the SF6 gas content in air or nitrogen over the full range, but also measures the moisture content of the SF6 which is essential when monitoring the dielectric strength of the gas.

The decomposition products of SF6 can be identified by analysing the SO2 content of the gas; this forms from the breakdown of SOF2 and SOF4 after an electrical discharge. The analyser incorporates an electrochemical SO2 sensor to measure ppm levels of sulfur dioxide. All three gases can be monitored and data-logged simultaneously and just a few minutes are required to get a stable reading.

Regular checking of SF6 gas insulated substations allows fault preventative maintenance programs to be implemented, and increases the life cycle of the SF6. The analyser has a gas output nozzle allowing all sampled gas to be recovered and recycled, ensuring that no SF6 gas is released into the atmosphere (in accordance with the Kyoto agreement).

The Multimeter can be supplied as a bench style instrument or a full kit in a transport suitcase, with a range of DILO compatible sampling hoses, couplings and a printer.

Features

• Continuous gas sampling of SF6 - SO2 - H2O (°dp OR ppmv)
• High precision katharometer for SF6 analysis over the range 0-100%
• Electrochemical SO2 sensor for trace analysis of contamination gas 0-100ppm.
• Ceramic dew-point sensor for moisture analysis -65°C to +20°Cdp (or ppmv)
• Sensor accuracy ± 1% of the full scale.
• Input pressure 0.5 to 10 bar.
• Gas flow rate 0.5 - 1 litre per minute controlled by flow gauge.
• Programmable alarms (fully programmable) with outputs and visual warning.
• RS232 / RS485, 0-5V and 4-20mA current loop outputs (both user programmable).
• On-Board Windows data logging software with MS-Excel compatible graphing.
• Supplied with a 2m armoured sampling hose with DLIO compatible fittings.
• Full sample Kit available (sample hoses, DILO couplings, printer, Peli-case)
• Compatible with DILO style gas recovery systems

Applications

• Controlling SF6 quality in switches, bus bars and circuit breakers in Gas Insulated Substations (GIS)
• SF6 insulated devices in power stations
• Checking for the build up of corrosive decomposition products such as SO2 present in the SF6
• Measuring the moisture content of SF6 gas by using a dew-point analyser
• Applying a condition based maintenance program (CBM) to extend the life cycle of the SF6
• Detecting the presence of leaks and SF6 discharge
• Indication of arcing and breakdown through the build up of corrosive by-products