SF6 gas analysers: purity, moisture, SO2
SF6 gas analysers measure the quality of the gas inside GIS and circuit breakers — purity, moisture and decomposition by-products — to confirm it still insulates and quenches arcs safely. The Amperis range for the electrical sector includes measure-and-return analysers that report gas condition on site without venting to atmosphere.
What it measures and how it works
A multi-gas analyser samples the compartment and reports SF6 purity (% by volume), moisture as dew point or ppmv, and SO₂ and other decomposition by-products (ppmv) created by internal arcing; some models also read HF, CF₄ or oil. A measure-and-return design pumps the sample back into the equipment, so a quality check produces no emissions — important both technically and under the F-gas rules.
How to choose the right analyser
- Select the parameters you need: purity, moisture and SO₂ are the core trio.
- Insist on a measure-and-return (zero-emission) gas path.
- Check resolution and range (ppmv for moisture/SO₂, % for purity).
- Look for an integrated pump, automatic sequencing and on-board logging.
- Confirm calibration intervals and traceability.
Need help specifying parameters? Do not hesitate to contact us.
Applications
- Commissioning checks on new GIS and breakers
- Periodic gas-quality monitoring
- Post-fault analysis after internal arcing
- Quality verification before gas reuse
Applicable standards
Amperis analysers are referenced to the IEC/EN framework (not national PN/PL variants):
- IEC 60376 — quality specification for new SF6
- IEC 60480 — reuse limits for recovered SF6 (purity, moisture, by-products)
- IEC 62271-4 — handling procedures and quality assessment
- IEC/EN 61010-1 and IEC/EN 61326-1 — instrument safety and EMC
Frequently asked questions
What is acceptable SF6 quality?
IEC 60480 sets the reuse limits — minimum purity and maximum moisture and by-product content. A reading inside those limits is fit for service; rising moisture or SO₂ signals ingress or internal arcing and warrants investigation.
Why measure SO₂?
SO₂ is a decomposition by-product formed when SF6 is exposed to electrical arcing or partial discharge. Detecting it early flags an internal fault long before it threatens the insulation.
Does analysing the gas release it?
It does not have to. Choose a measure-and-return analyser, which returns the sampled gas to the equipment — avoiding emissions and supporting F-gas compliance.
Technical resources
Combine quality testing with SF6 leak detectors and handling and recovery units, or return to the SF6 overview and circuit-breaker testing. Request a quote.