Forming gas analyser with extended ultra-low oxygen range
Controlling a forming gas atmosphere —nitrogen with hydrogen— means measuring extremely low oxygen partial pressures and knowing its moisture content at the same time. The Rapidox 2100-FGA extends its zirconia sensor range down to 10E-30 ppm O2, with ±1 % of the actual concentration or 0.5 ppm accuracy and a typical response under 4 s, and calculates the H2O dewpoint thermodynamically from the hydrogen content entered by the operator; with insertion probes it works in gas up to 1000 °C.
Rapidox 2100-FGA key data
- Oxygen measurement: extended range of 10E-30 ppm to 30 % O2, accuracy of ±1 % of the actual concentration or 0.5 ppm (whichever is greater) and a typical response under 4 s for 90 % of a step change.
- Moisture without an extra sensor: H2O dewpoint calculated thermodynamically from the hydrogen content, shown in °Cdp or ppmV alongside oxygen; a pure hydrogen mode is included.
- Temperature: gas up to 650 °C, or up to 1000 °C with insertion probes; temperature is read at the sensor head up to 660 °C and above that by the standard type K thermocouple (0-1250 °C, ±1 °C).
- Pressure and sample: working pressure up to 10 bar (200 bar burst), vacuum-tight below 10E-4 Torr and a flow rate of 0.1 to 4 L/min (1 L/min recommended), or static gas.
- Sensor: pre-calibrated hot-swap design, replaced without a PC; life above 17,500 h and a 2 m high-temperature cable extendable to 25 m.
- Auxiliary measurements: socket for standard 4-20 mA transmitters, configurable for pressure or vacuum; optional pressure sensor for −1 to 0 bar, 0-5 and 0-10 bar.
- Alarms and outputs: programmable high and low alarm relays, 0-5 V (min. 5 kΩ load) and 4-20 mA (max. 500 Ω load), RS232 (RS485 optional) and Modbus RTU/Ethernet, 20 × 4 character OLED display and pin-code protection.
- Installation: 19″ panel mount (300 mm × 4U) or IP65 wall housing, 250 × 263 × 150 mm and 3.5 kg with sensor, 90-260 V AC with 30 W maximum; operation from 5 °C to 35 °C, 900-1,100 mbar absolute and 10-90 % RH.
Advantages
A range built for forming gas
The zirconia sensor extends its measurement down to 10E-30 ppm O2, covering the ultra-low partial pressures of forming gas mixtures; with insertion sample tubes it operates up to 1000 °C.
Dewpoint without a moisture sensor
The analyser resolves thermodynamic equations to deliver the H2O dewpoint of the mixture: the operator enters the hydrogen content and the value is displayed in °Cdp or ppmV alongside the oxygen reading.
Fast, continuous response
Analysis is on-line, with about 4 s for a 90 % response to a step change; temperature is read at the sensor head up to 660 °C and by the standard type K thermocouple above that.
Hot-swap sensor
The pre-calibrated sensor is replaced on site without a PC, keeping downtime to a minimum.
Connected to the process
Programmable alarm relays and analogue outputs, RS232 and Modbus RTU communications, auxiliary socket for 4-20 mA transmitters and data-logging software.
Applications
- Hydrogen forming gas in metal heat treatment.
- Annealing, sintering and brazing atmospheres.
- Manufacturing under protective atmospheres.
- Research and development.
About the product
The Rapidox 2100-FGA is a special variant of the zirconia oxygen analyser for continuous duty, panel mounted (19-inch) or in a wall-mountable IP65 housing, with sensors up to 25 m away. It complies with EMC Directive 2004/108/EC and carries UL/ETL certification UL-61010-1.
Available accessories: calibration kit, calibration service, multiplex sampling system, sample pump, wall-mount cabinet, auxiliary pressure sensor, vacuum fittings (CF50, ISO KF25), stainless probe, filters and thermal printer.
Technical specifications
| O2 range | 10E-30 ppm to 30 %; ±1 % of reading or 0.5 ppm |
| Response | ≈4 s for a 90 % step change; sensor life over 17 500 h |
| H2O reading | Dewpoint by thermodynamic calculation, °Cdp or ppmV |
| Maximum gas temperature | 650 °C (1000 °C with insertion probes) |
| Thermocouple | Type K, 0-1250 °C, ±1 °C (included) |
| Outputs | 0-5 V, 4-20 mA, RS232/RS485, Modbus RTU/Ethernet |
| Supply | 90-260 V AC, 50/60 Hz |
| Dimensions and weight | 250 × 263 × 150 mm; 3.5 kg with sensor |
| Working pressure | Up to 10 bar (200 bar burst); vacuum-tight below 10E-4 Torr |
| Sample flow | 0.1-4 L/min (1 L/min recommended); static gas or vacuum |
| Operating conditions | 5 °C to 35 °C; 900-1,100 mbar absolute; 10-90 % RH |
Frequently asked questions
Can it measure at furnace temperature?
Yes. The Rapidox 2100-FGA accepts gas up to 650 °C and reaches 1000 °C with insertion probes. Temperature is read at the sensor head up to 660 °C and above that by the standard type K thermocouple, which covers 0 to 1250 °C with ±1 °C.
Is it also suitable for pure hydrogen?
Yes. Besides the calculation for forming gas mixtures, in which the operator enters the hydrogen content, the Rapidox 2100-FGA offers a pure hydrogen mode. In both cases it measures oxygen from 10E-30 ppm with ±1 % of the actual concentration or 0.5 ppm, whichever is greater.
What is forming gas?
A nitrogen-hydrogen mixture used as a protective atmosphere in metal heat treatment; its oxygen partial pressures are extremely low, which demands the extended measurement range.
How is the dewpoint obtained?
By thermodynamic calculation: the operator enters the hydrogen content of the mixture and the analyser shows the dewpoint in °Cdp or ppmV together with the oxygen reading.
Can the sensor be replaced on site?
Yes. The pre-calibrated hot-swap sensor is exchanged locally without a PC.
Which mounting options exist?
Panel mount (19-inch) or wall-mountable IP65 housing, with the sensor remote up to 25 m.
