Rapidox 6100 Clean Air Pumpback — Clean Air Insulation Gas Analyser

Rapidox 6100 Clean Air Pumpback measures SF6 and clean-air mixtures with minimal gas loss during sampling.

Overview

The Rapidox 6100 Clean Air Pumpback is a portable analyser from the British company Cambridge Sensotec for equipment insulated with Clean Air. Clean Air, also called Dry Air, is a purified and dried blend of nitrogen and oxygen that manufacturers use to replace SF6 in low, medium and high voltage apparatus.

The instrument measures mixture composition, moisture and NO₂, then returns the sample to the equipment. It does not measure SF6.

Why Clean Air must be monitored

According to Cambridge Sensotec, Clean Air has zero global warming potential versus 23,900 for SF6. But its insulating performance depends heavily on moisture. If the sample mixes with ambient air, it loses its dryness and the measurement becomes meaningless.

Regular analysis shows:

• mixture composition — the O₂/N₂ ratio after filling and topping up;
• moisture — the key parameter for Clean Air;
• NO₂ — a sign of discharge or arcing inside the apparatus.

How a measurement works

1. Connect to the compartment or cylinder through a Rectus-style fitting; DN8 and DN20 adaptors are supplied.
2. The instrument draws a small amount of pressurised gas. A vacuum purge and internal storage keep ambient air out.
3. Readings stabilise within a few minutes; moisture needs at least 6 minutes.
4. The compressor returns the gas at up to 10 bar. Results are logged and printed on demand.

Sensors and ranges

Parameter	Range	Accuracy	Sensor type	Calibration	Life span
Air / O₂ / N₂	0–100 % air, 0–30 % O₂	±1 % FS	electrochemical	12–24 months	up to 5 years
H₂O (dew point)	-60 to +20 °Cdp (10–24,000 ppmV)	±2 °Cdp	polymer	12 months (sensor exchange)	2–3 years
NO₂	0–20 or 0–200 ppm	±2 % FS	electrochemical	12–24 months	up to 4 years

Technical specifications

Parameter	Value
Measurement time	2–8 min (min. 6 min for H₂O)
Warm-up	3–4 min at 20 °C, 15 min for full accuracy
Inlet pressure	0.5–35 bar (up to 10 bar in pump-back mode)
Sample flow	0.5 L/min
Pump-back compressor	up to 10 bar, up to 15 cycles per charge at 20 °C
Display	7" (178 mm) colour LCD touch screen
Printer	built-in thermal printer
Memory	4 GB, about one year of continuous logging
Data export	Excel-compatible files to a USB stick
Power	lithium battery up to 8 h, 4–6 h charge, mains 90–260 V
Operating conditions	-10 to +40 °C, 10–90 % RH, 600–1100 mbar
Housing	IP66 Peli case with trolley and handles
Dimensions	270 × 560 × 450 mm (H × W × D)
Weight	21 kg with case

Other Rapidox 6100 models

• Rapidox 6100 QU4D — SF6, C4-FN, C5-FK and Clean Air in one instrument.
• Rapidox 6100 C4-FN & C5-FK — g3 and AirPlus mixtures.
• Rapidox SF6 6100 Pump Back — SF6.

Supply in Kazakhstan

KEG TRK supplies Cambridge Sensotec analysers to power utilities and contractors. We help choose the model for your equipment fleet and select adaptors. Price on request.