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Frequently Asked Questions Flue Gas Analyzers

Have questions about flue gas analyzers? Read our answers to frequently asked questions from an expert in the gas analyzer industry.

1.What are the main differences between online gas analyzer Gasboard-3000Plus and Gasboard-3000UV? Which model should I choose?

• Measurement principle difference:

Gasboard-3000Plus is designed based on Micro-flow NDIR technology;

Gasboard -3000UV is designed based on ultraviolet differential optical absorption spectroscopy (UV-DOAS) technology; If no specific technology limitation from local government, both models can work well for flue gas monitoring.

• Measurement range difference:

Gasboard-3000Plus: more frequently used for general emission limit (0-500ppm or higher range); Gasboard-3000UV: more frequently used for ultra-low emission limit (0-50mg/m3, 0-100mg/m³) of SO2 and NO.

• Measuring gases difference:

Gasboard-3000Plus can measure SO2, NO, CO, CH4, CO2 with micro-flow NDIR gas sensors, and can match NDUV sensors for measuring NO2.

Gasboard-3000UV can measure SO2, NO, NO2 simultaneously, and can match dual-beam NDIR to measure CO2, but can not measure CO together.

2.What are the advantages of Micro-flow NDIR and UV-DOAS technology?

Micro-flow NDIR technology:

• Adopting the Patent (PCT/CN2018100767) dual-chamber infrared sensor structure for high measurement precision.

• Measurement range for SO2, NO, CO, CO2 can be down to 0-200ppm.

• Constant temperature design eliminated the effects of environmental temperature fluctuations.

• No cross interference between measurement gases.

• High stability and less maintenance.

UV-DOAS technology:

• Direct NO2 detection without Nox converter.

• Able to achieve higher accuracy of NO2 measurement (±2%FS).

• No moisture & vibration interference.

• Measurement of ultra-low SO2, NO, NO2 concentration as low as to 100mg/m3.

• Good seismic performance, suitable for ship or vehicle applications.

• TUV CE certification.

• Easy for CEMS integration.

3.What are the applications of flue gas analyzer and CEMS?

By measuring purpose:

• Industrial production process safety monitoring

• Industrial combustion efficiency monitoring

• Industrial emission monitoring

By measuring points:

• Process safety monitoring: coal milling, coal bin

• Combustion process monitoring

• Desulfurization process monitoring

• Denitration process monitoring

• Stake emission gas monitoring

By industries:

Power plant, Cement, Iron Steel, metallurgy, Chemical, Petrochemical, Waste incineration, ceramic, glass,etc.

4.Do you have any reference projects in my country for continuous emission monitoring systems?

We have experience with gas analysis and CEMS integration for 18 years and have exported to more than 80 countries. For more project references, please contact with us by email:

5. If we already have an existing CEMS installed onsite, can we use your gas analyzer to replace the defective gas analyzers in the current CEMS?

Yes, our flue gas analyzer is a standard 19" rack type design with digital (RS-485/RS-232) and analog (4-20mA) output which can be easily integrated in existing CEMS and perfectly take the place of the existing analyzers to measure SO2, NO, CO, CO2, O2 with affordable cost.

6. How is the flue gas analyzer calibrated and how often should it be done?

Our flue gas analyzer is recommended to be calibrated each 3-6 months to guarantee the long term performance. Our manual will have detailed calibration steps. For more resources, please contact us by email:

7. What is the life time of gas sensors in flue gas analyzer and if you sell them as spare parts?

The sensor life time depends on working conditions and maintenance frequency: UV-DOAS sensors can work for 3-6 years; NDIR or Micro-flow NDIR normally can work for 6-8 years; ECD normally can work for 1~2 years. All the core sensors can be supplied as replacement item with good price. For more information, please contact with us by email:

8. What kind of information should we offer to require a quotation?

• Your application information: such as industry and process description.

• Gases need to be measured and measurement ranges.

• Sample gas conditions, such as the temperature, pressure, flow rate, dust and water vapor.


  • Wuhan, Hubei, China
  • Hubei Cubic-Ruiyi Instrument Co.,Ltd.