Gas analyzers

SIRA ROA Premix

The SIRA ROA Premix is a specialized application of the stationary SIRA analyzer designed for the continuous determination of residual oxygen content following the combustion of premixed fuel gas/air mixtures. Precise control of the combustion process is essential for achieving maximum energy efficiency, consistent product quality, and minimal pollutant emissions.

The measurement principle combines a catalyst for oxidation of the gas sample with a zirconium oxide sensor for precise determination of the remaining oxygen content. This enables reliable monitoring of the combustion conditions and supports accurate adjustment of the fuel gas/air mixture.

A key feature of the SIRA ROA Premix is its very low gas consumption during the actual measurement process, achieved through a specially designed gas metering and mixing system. The reduced gas flow helps extend the service life of both the zirconium oxide sensor and the catalyst, resulting in lower maintenance requirements and reduced operating costs.

For reliable operation, the system provides automatic monitoring of all relevant measurement components. A controlled and adjustable bypass ensures fast response times, allowing changes in the process to be detected quickly.

Typical applications include fiber optic manufacturing and glass melting processes, where precise control of premixed combustion gases is critical for stable process conditions and consistently high product quality.

Key benefits: fast response time, low maintenance requirements, adjustable bypass, automatic catalyst monitoring, easy system integration, and multiple interface options.

Technical dataValue
Dimensions H × W × D (mm)660 × 360 × 300, aluminum housing
WeightApprox. 20 kg
Degree of protectionIP42
Operating temperature5–50 °C
Ambient humidityMax. 95% relative humidity, non-condensing
FasteningWall mounting, wall bracket included
Electrical connection110–230 VAC, 50–60 Hz, 185 VA
Display / Operation7"-touchscreen display
Gas inletProcess gas, calibration gas, test gas
Gas connection6 mm stainless steel clamping ring
Process gasesPremixed fuel gases
Ambient pressure range950–1,100 mbar
Gas inlet pressure40–60 mbar
Gas consumption20 l/hour
Communication options0/4–20 mA, digital output, relay, fieldbus (optional)
Repeatability± 0.1 Vol. %
Range0.1% O₂ to 20.9% O₂
Precision±2% of measured value or ±0.1% O₂, whichever is greater
Sensor flow2–3 l/h
Response time t₉₀< 5 s
Calibration gas suggestionAir & O₂ in N₂
Power supply115–240 V AC

The SIRA product series in comparison

Industry applications

These products can be used in the following sectors.

Iron and steel production

Our appliance series have been used in iron and steel production for many decades.

Biogas

Union Instruments products have proven themselves extensively in biogas upgrading plants.

Petrochemicals and refineries

We produce customized and flexible measurement technology solutions for the petrochemical industry and refineries.

Glass and ceramics

Perfectly coordinated appliance technology for glass and ceramic applications that works both safely and economically.

Natural gas

Our INCA multi-gas analyzers provide efficient solutions for processes in natural gas plants.

Generating energy from waste

Our appliance technology makes an important contribution to the functionality of environmentally friendly and energy-saving system concepts.

Service

We clarify administrative and commercial issues for you.

+49 721 680381-30

Support

You can open a support ticket for technical support for your product.

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Distribution

We prepare quotations for you, clarify questions about invoicing and manage your maintenance contract.

+49 721 680381-20

Downloads

Here you will find various downloads to support you.

Brochures, data sheets and application reports – we have all the relevant information for you here.

Industries

Our key application areas at a glance.

We supply a wide range of industrial plants such as steel production, the natural gas industry and biogas producers.

Products

Special products for your industrial application.

Our range includes the INCA, CWD and SIRA product series and the CAM module – combined with top advice and service.

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