YOKOGAWA EXAxt ZR402G, User Manual

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<1. Overview>
1-1
IM 11M12A01-04E 11th Edition : Jul. 19, 2017-00
1. Overview
The EXAxt ZR Integrated type Zirconia Oxygen/Humidity Analyzer is used to monitor and
control the oxygen concentration in combustion gases, in boilers and industrial furnaces, for
wide application in industries which consume considerable energy-such as steel, electric power,
oil and petrochemical, ceramics, pulp and paper, food, or textiles, as well as incinerators and
medium/small boilers. It can help conserve energy in these industries. The EXAxt ZR also
contributes to preservation of the earth’s environment in preventing global warming and air
pollution by controlling complete combustion to reduce CO
2
, SOx and NOx.
The EXAxt ZR Integrated type Zirconia Oxygen/Humidity Analyzer integrates both probe and
converter. The analyzers need not use a sampling device, and allow direct installation of the
probe in the wall of a flue or furnace to measure the concentration of oxygen in the stack gas of
the temperature up to 700°C.
The EXAxt ZR Integrated-type Zirconia High-temperature Humidity Analyzer integrates
the detector and the converter in one unit. This analyzer can measure humidity of hot air
continuously, so can be used to measure humidity of air in driers which are heated by steam or
electricity. It can also be used in a variety of manufacturing applications with humidifiers, as well
as with driers, for humidity measurement and control. It can help improve productivity in these
application fields.
The probe uses a high-reliability Zirconia sensor and a heater assembly that can be replaced on
site.
The analyzer is equipped with three infrared switches, which enable the user to operate the
equipment without opening the cover on site. Analyzer calibration can also be fully automated
and the automatic calibration unit is provided. Choose the equipment which best suits your needs
so that an optimal combustion control system can be obtained.
Some examples of typical system configuration are illustrated below:
1.1 < EXAxt ZR > System Configuration
The system configuration should be determined by the conditions; e.g. whether the calibration
is to be automated, and whether flammable gas is present and requires safety precautions. The
system configuration can be classified into three basic patterns as follows:
1.1.1 System 1
This is the simplest system consisting of an integrated type analyzer. This system can be
implemented for monitoring oxygen concentration in the combustion gases boiler, and can be
implemented for monitoring humidity in a production process such as food production.
No piping is required for the reference gas (air) which is fed in at the installation site. The ZO21S
standard gas unit is used for calibration.
Zero gas from this unit and span gas (air) is sent to the probe through a tube which is connected
during calibration.