Oxygen Zirconia In-situ analyser

Zirconia in-situ oxygen analysers are used to measure oxygen levels and combustion control in furnaces and boilers. The gas analysers are used to control the air-to-fuel ratio of burners in a controlled system to ensure an efficient process. This O2 gas analyser is perfect for controlling and optimizing excess air in a combustion. This measurement instrument provides significant fuel savings.

Oxygen analyser: Optimization of combustion efficiency and compliance with environmental standards

analyser combustion efficiency optimization

Ideal for combustion control of boilers, incinerators and furnaces, an oxygen analyser helps reduce CO₂, SOx and NOx emissions while saving your energy.

This gas analyser is specially designed for continuous measurement of oxygen concentration in flue gas and smoke from boilers in power plants, industrial furnaces (crematoria, glassworks, firing) and incinerators.

These zirconium oxide oxygen measurements are used to regulate the air-fuel ratio of burners in a controlled system to ensure optimum process efficiency in an industrial plant.

This instrument is ideally suited to control and optimize the excess air of a combustion. Therefore it allows an important saving on fuel consumption.

combustion air excess control and optimization

operating principle diagram

Operating principle of the In-situ Zirconia oxygen analysers

The operation of the in situ oxygen analyser is based on the property of zirconium oxide, also called zirconia, which conducts oxygen ions when heated.

An analyser obtains the measurement of O₂ concentration by detecting the electromotive force generated by the difference in O₂ content between air and the sample gas.

o2 sensor principle

Applications of oxygen analysers with zirconium oxide probe

applications of analysers oxygen

The ATEX type zirconia oxygen analyser is suitable for combustion monitoring in hazardous areas. These analysers comply with the most demanding international standards. They are CE, FM, ATEX and QAL1 certified.

O2 gas analyser for combustion

Advantages of O2 oxygen analysers

advantages of oxygen analysers
  • Reduction of excess combustion air
  • Saves fuel by increasing combustion efficiency
  • Long life of the combustion plant
  • Quick and easy replacement of the zirconia element
  • Safety and a high degree of protection
  1. Thermocouple cut-off detection for temperature control in the detector by the analyser when the power supply is cut off.
  2. In the event of an emergency, the converter also cuts off the power supply at emergency, in response to an external contact input.
  3. The key lock function prevents operational errors.

Why choose an in situ oxygen analyser with a zirconia probe?  

why choose in situ O2 analyser with zirconium probe

The In-Situ O2 analyser with Zirconia probe offers an accurate measurement of ± 1% on the measured oxygen concentration. It is also very stable over time due to its zirconia probe technology. This system is suitable for processes with high temperatures up to 1500°C depending on the type chosen.

This probe is a very reliable and robust instrument, it can be used in the most difficult conditions (dust, smoke, etc.). Its construction with resistant materials such as 316L stainless steel guarantees an excellent resistance to humid and corrosive atmospheres.

The zirconium oxide analyser is equipped with a backlit LCD display for easy reading of results even in the darkest of places.

The transmitter is also equipped with an audible and visual alarm when preset limits are exceeded.

Among the benefits, they offer:

in situ zirconia probe applications diagram


Operating principle and application

At the heart of this device is an in-situ zirconia sensor that guarantees fast, accurate oxygen measurement. Mainly dedicated to O2 measurement in non-combustible gas mixtures, this analyser is particularly suited to critical environments such as industrial heat production in refineries, petrochemical reactor furnaces, and other large combustion plants.

Exceptional Performance

The user-configurable measurement scale ranges from 0 to 2% up to 50% vol. oxygen. Exceptional repeatability of ≤ ± 0.5% PE and linearity of ≤ ± 2% PE ensure consistent, accurate performance under varied operating conditions.

Reactivity and Advanced Communication

With a fast response time of 4 to 7 seconds to reach 90% of response, theanalyser offers near-instantaneous measurement to adapt to rapidly changing conditions. Analog output of 4-20 mAdc or 0-1 Vdc offers flexibility in data collection. In addition, contact outputs include 6-point SPST-NO contacts for critical functions such as high/low limit alarm, maintenance in progress, purge in progress, calibration in progress, and the analyser faults.

Integrated Security and Advanced Options

Integrated safety functions, such as power cut-off in the event of thermocouple failure, add an extra layer of protection. The lockout function prevents potential operating errors. Advanced options include combustion efficiency display, cleaning, automatic calibration, selector valve and flowmeter, providing further customization to the specific needs of each application.

Installation and power supply

The analyser offers installation flexibility with panel- or pipe-mounting options. The cable length between controller and detector can be up to 100 meters, offering adaptability to a variety of factory configurations. Power can be supplied at 100-120 Vac or 200-240 Vac, at a frequency of 50/60 Hz, guaranteeing worldwide compatibility.

Depending on the conditions of your processes you can combine the modules below

combine modules

Oxygen gas analyser model selection

Select the required modules combination according to the process conditions using below table.

Process conditionsModule selection
Application exampleTemperatureDustTube materialBack purgeTube typeTube code (*)Detector type
Gas boiler≤ 600 °C≤ 0.1 g/Nm³SS316NoStandard guide tube631B562-0#ZFK8
Biomass, oil, coal boiler/ Incinerator≤ 600 °C≤ 5 g/Nm³YesGuide tube with backpurge631B563-0#
≤ 25 g/Nm³YesDirect tube for high particulate631B673-0#
YesDirect tube for HP with deflector631B677-0#
≤ 1000 °C≤ 0.2 g/Nm³SS310NoDual Flange (DF) Guide tube for high temperature (HT)631B685-0#ZFKH
≤ 5 g/Nm³YesDF Guide tube for HT with backpurge631B684-0#
≤ 25 g/Nm³YesDirect tube for HT and HP631B675-0#
YesDirect tubefor HT and HP with deflector631B678-0#
Incinerator / Furnace / Glass / Metal industry≤ 1300 °C≤ 0.2 g/Nm³KanthalNoGuide tube for very high temperature631B682-0#
≤ 5 g/Nm³YesGuide tube for very high temperature with backpurge631B683-0#
≤ 800 °C≤ 0.5 g/Nm³SS310YesZTA ejector moduleZTA2ZFK8
≤ 1500 °CSiCYesZTA ejector moduleZTA1
Remarks(*) The last digit of the tube code is dedicated to the tube insertion length as per below list:
"1" = 300 mm"2" = 500 mm"3" = 750 mm"4" = 1000 mm"Z" = specific length -> consult Fuji

Notes :

- In case of very humid gas, keep the flange hot enough to prevent condensation
- In case of highly corrosive gas, please consult Fuji for special materials
- If the gas flow is lower than 5 m/s, use ejector module instead of flow tube

How to choose an in situ oxygen analyser with a zirconia probe?  

You need to measure the oxygen concentration of your industrial process?

how to choose my oxygen analyser

We help you configure your oxygen measurement platform for :

  • Combustion control
  • Safety measurement
  • Environmental monitoring
  • Furnace atmosphere control
  • Inerting process
  • Other industrial processes

With the data from this questionnaire, our engineers will select the best combination for reliable and accurate oxygen analysis. Do not hesitate to send us, in writing or in the form of a diagram, on the last page of this questionnaire or as an attachment, any additional information that would allow us to understand the specifics of your process, and thus adapt the configuration of your O2 analysis solution.

Download Questionnaire

Application questionnaire analyser O2 zirconia

Download the questionnaire so that we can suggest the best solution for your application!


Immediate optimization of your combustion guaranteed thanks to Fuji Electric's in situ oxygen analysers!