Oxygen Analyzers

What Are Oxygen Analyzers?

Oxygen analyzers provide valuable measurements in combustion control, process quality, safety and environmental applications. These are used in a variety of measurement scenarios including boiler trimming in power plants, furnace optimization in refinery and petrochemical applications, process safety in vent headers, product quality in ethylene production, and many other applications.

Yokogawa offers a full range of product solutions including an industry leading zirconia oxygen probe series, as well as a line of cutting edge tunable diode laser spectrometers. 


  • Zirconia Oxygen/Humidity Analyzer ZR22G, ZR802G

    This Oxygen concentration and humidity at high temperatures consists of a ZR22G detector equipped with a long-life and highly reliable zirconia sensor, and a converter ZR802G equipped with digital communication and data log functions.
    ZR22G and ZR802G can be measured directly and continuously without a sampling device. It is easy to maintain and reduce operating costs by self-diagnosis of sensor deterioration (without using calibration gas )and replacing the heater assembly on site.

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  • Multi Channel Oxygen Analyzer System ZR22/AV550G

    The AV550G Multi Channel Oxygen Analyzer System allows for measurements on up to eight ZR22 probes simultaneously. The ZR probe's in-situ measurement method does not require any process conditioning or extractive sampling, reducing maintenance costs and resulting in faster measurement response to changes in the process.

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  • Integral Oxygen Analyzer ZR202

    The ZR202 transmitter/detector combines benefits of the ZR402 remote analyzer and the ZR22 detector into an intelligent, rebuildable, low-cost measurement device for in-situ humidity measurement.

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  • Calibration Units

    Yokogawa's Zirconia oxygen detector systems offer a variety of calibration units for quick, easy control of calibration gases giving the user simple, accurate calibration.

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  • WZ-H Cables

    • WZ-H cables
    • Compatible with ZR22, ZR402, and AV550G Oxygen Analyzer Systems 
    • Transmit sensor/detector signal to analyzer 
    • Electrical input for cell temperature control
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  • FLY ASH Filter

    The accumulation of fly ash on the zirconia cell affects its ability to measure oxygen concentration. Fly ash and its constituents can reduce the life of the zirconia cell and affect the cells response time to changes in gas concentration. Yokogawa's large surface area sintered metal filters are designed to keep particulate and ash off the measurement cell.

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  • Product Finder

    This web tool makes it easier to find products according to the application, measurement conditions and required specifications.

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  • Yokogawa's CENTUM CS 3000 DCS Monitors and Controls Operations at Poultry Litter-to-energy Plant
  • The boiler and turbine startup procedures reduces operator workload and helps to ensure a smooth and safe startup

Enhance the efficiency and safety of your vapor recovery systems and flare/vent headers with Yokogawa's cutting-edge Tunable Diode Laser Spectrometers – the TDLS8000 and TDLS8220. Elevate your oxygen measurement capabilities with our interference-free analyzers, providing direct measurements. Experience unparalleled reliability, ensuring minimal upkeep and secure operations without the need for system shutdowns.


A furnace for heating slabs needs to be operated under low oxygen conditions at high temperatures of 1000°C and above to prevent oxidation of the steel. The measurement of oxygen concentrations in the furnace is essential in this process. (AN 10M01F01-03E)


Package boilers require less fuel and electric power to operate and are widely used in the pharmaceutical, food, ceramic, and other industries. A package boiler operates more efficiently if the oxygen concentration in the flue gas is reduced. 


In a hot blast stove, the by-product gas produced in a coke oven is burned to preheat the air blast for the blast furnace. To improve the combustion efficiency and conserve energy in a hot blast stove, it is essential to be able to control combustion by measuring and adjusting the oxygen concentration in the exhaust gases.


A package boiler operates more efficiently if the oxygen concentration in the flue gas is reduced. Optimizing air intake for boiler operation requires continuous measurement of the oxygen concentration in the flue gas.


Combustion furnaces such as heating furnaces and boilers in plants include various sizes and types, and serve as energy sources, that is, they are cores in all production activities. Because a large amount of fuel such as gas or fuel oil is consumed in plants, their combustion efficiency directly affects the performance and running cost of the plants. 

The password to access the maintenance and commissioning area is 77
AV8C Channel reset code
You can use code 58 to reset a single AV8C channel.  First scroll the display to the channel you would like to cycle, then enter code 58. 
Here is the link to download the AV8G Manual.
The part number you see on the channel card circuit board is not the part number for the channel card. It is the part number for the circuit board before any parts are installed.  There are 2 versions on the channel card.  If you look at ...
The AV550 automatically turns off the power to the channel card when it is removed. You have to either cycle power to the whole unit, or use the channel card power.  To get to the channel card power menu hit the Setup Key (wrench). See below:&n...
You can use the password JAVAJAVA to get past the password screen. Make sure you go to the password menu change the password setting. 
Yokogawa has been making Zirconia Oxygen Analyzers for over 30 years. The older O2 probes and analyzers used a transistor temperature sensor. The newer units use a PT1000 RTD. We discontinued the ZO21D probe and both the AV8G and ZA8C analyzers over ...
Meter Checks: Heater: 57-85Ω (typical is 62-67Ω) Typical failure is Open or shorted TC: if the probe is at room temperature -  less than 3Ω, in the stack and hot less than 100Ω (it is a type K Thermocouple) Typical failure is ope...
ZR22 Bolt Sizes
The ZR22 probes have the following bolt sizes  Cell Bolts (4 ea.) - 8mm  Housing bolts (4 ea.) - 10mm  Heater strut retaining nut (K9470BA) - Custom thread. You may need the nut removal tool to loosen this nut: You can purcase it se...
The wiring between the ZR402 Detector, the ZR22 Sensor, and the AC1 Autocal Panel is shown below. The Wiring between the ZR402G and the ZR22G must be installed in 2 separate conduits, one for the signal cable, and the other for the heate...
If you have set a password and have forgotten it you can use the password "MOON" to get into the configuration menu. Then you will be able to modify/view the password that is set in the unit.  Note: if you have not set a password just...
The password to get in all the maintenance and commissioning menus is 16 
ZR22S: Option "B" Adder
This is the Japanese GS sheet, containing a number of options we rarely sell here in the US. Contact Support at 800-524-7378 or support@us.yokogawa.com for price and delivery information.    ...




Yokogawa’s new TDLS8000 houses all of the industry’s leading features in one robust device. The platform design is for in situ measurements which negate the need for sample extraction and conditioning. The non-contacting sensor allows for a variety of process types including corrosive, abrasive and condensing. The first generation platform has been proven in many others for the measurements of O2, CO, CH4, NH3, H2O and many more NIR absorbing gases. This second generation platform has improved reliability and ease of installation and maintenance while still meeting or exceeding designed application demands.


How to change a channel card on an AV550G without disturbing the other seven channels.

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