Rapidox 6100 QU4D Multi-Gas Pumpback — SF6, C4-FN, C5-FK and Clean Air Analyser

Configurable Rapidox 6100 QU4D platform for comprehensive gas quality analysis in substations and GIS.

Overview

The Rapidox 6100 QU4D Multi-Gas Pumpback is a portable analyser from the British company Cambridge Sensotec for gas-insulated electrical equipment. It handles four insulation types: SF6, C4-FN (g3) and C5-FK (AirPlus) mixtures, and Clean Air. For a utility where older SF6 GIS sits next to new SF6-free apparatus, it is one instrument instead of several.

In one cycle the analyser measures gas purity, moisture and decomposition products. Afterwards the sample is returned to the equipment, so no gas is lost or released.

Supported mixtures

Insulation	Mixture	Measured
SF6	SF6 and SF6 + CF4	SF6 purity, H₂O, SO₂, HF, H₂S, CO, CF4
C4-FN (g3)	C4-FN + CO₂ / O₂	C4-FN, CO₂, O₂, H₂O, CO
C5-FK (AirPlus)	C5-FK + CO₂	C5-FK, CO₂, H₂O, CO
Clean Air	N₂ + O₂	O₂ / air, H₂O, NO₂

In each mode the instrument measures up to eight parameters at once. The sensor set is chosen at ordering and can be extended later.

How a measurement works

1. Connect the instrument to the compartment or cylinder through a Rectus-style fitting (DN8 and DN20 adaptors supplied) and select the gas type.
2. When switching gas, the instrument purges and sends the remainder to a recovery bag.
3. The Rapidox draws a small amount of pressurised gas; a vacuum purge and internal storage keep air out of the sample.
4. All parameters are measured simultaneously; a stable reading takes a few minutes.
5. The compressor returns the gas at up to 10 bar. Results are logged and printed.

Sensors and ranges

Parameter	Range	Accuracy	Sensor type	Calibration
SF6	0–100 %	±0.5 %	IR or density	12–24 months
H₂O (dew point)	-60 to +20 °Cdp (10–24,000 ppmV)	±2 °Cdp	polymer	12 months (sensor exchange)
SO₂	0–100, 0–150, 0–500 or 0–2000 ppm	±2 % FS	electrochemical	12–24 months
HF	0–10 or 0–20 ppm	±2 % FS	electrochemical	12–24 months
CF4	0–80 %	±1 % of reading	calculated	not required
H₂S	0–100 ppm	±2 % FS	electrochemical	12–24 months
CO	0–500, 0–1000, 0–2000 or 0–5000 ppm	±2 % FS	electrochemical	12–24 months
Air / O₂ / N₂	0–100 % air, 0–30 % O₂	±1 % FS	electrochemical	12–24 months
CO₂	0–100 %	±0.5 %	IR	12–24 months
C4-FN / C5-FK	0–20 %	±0.5 %	—	12–24 months
NO₂	0–20 or 0–200 ppm	±2 % FS	electrochemical	12–24 months

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	0.3–35 bar (up to 10 bar in pump-back mode)
Pump-back compressor	up to 10 bar, up to 15 cycles per charge at 20 °C
Test programmes	IEC and CIGRE, plus custom
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
Housing	IP66 Peli case with trolley and handles
Dimensions	270 × 560 × 450 mm (H × W × D)
Weight	21 kg with case

QU4D or a dedicated model?

Equipment fleet	Model
SF6 only	Rapidox SF6 6100 Pump Back
g3 and AirPlus only	Rapidox 6100 C4-FN & C5-FK
Clean Air only	Rapidox 6100 Clean Air
Mixed, or planning a move to alternative gases	Rapidox 6100 QU4D

Supply in Kazakhstan

KEG TRK supplies Cambridge Sensotec analysers to power utilities and service contractors. We help select the sensor set for your GIS and breaker fleet and the adaptors for your apparatus. Price on request.