Zirconia Oxygen Analyzer

The ZR402G zirconia oxygen analyzer features a touch screen LCD with excellent operability for settings, calibrations, and trend graph viewing. The probe uses a highly reliable zirconia sensor and a field-replaceable heater assembly. The applications range from energy-consuming industries, such as iron and steel, electric power, and oil and petrochemical, to various combustion facilities, such as incinerators and small- and medium-sized boilers.

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ZR202G Integrated Type Zirconia Oxygen Analyzer

The ZR202G zirconia oxygen analyzer features an integrated probe and converter and does not require a sampling system. The probe can be inserted directly into a stack or furnace to measure the oxygen concentration of the stack gas. The probe uses a highly reliable zirconia sensor and a field-replaceable heater assembly. The converter features infrared switches, allowing a user to operate the instrument without opening the cover in the field.

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ZR22S/ZR202S Explosionproof Zirconia Oxygen Analyzer

The ZR22S explosionproof zirconia oxygen probe is used together with a ZR402G non-explosionproof converter installed in a non-hazardous area. The probe can be inserted directly into a stack or furnace to measure the oxygen concentration of the stack gas. The ZR202S explosionproof integrated type zirconia oxygen analyzer has both a probe and a converter, and does not require a sampling system. The probe uses a highly reliable zirconia sensor and a field-replaceable heater assembly. The converter features infrared switches, allowing the user to operate the instrument without opening the cover in the field.

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AV550G Zirconia Oxygen Averaging Converter

The AV550G Averaging Converter can accept inputs from up to eight zirconia oxygen detectors, reducing installation and maintenance costs. It sends output signals for individual and multiple (averaged) oxygen concentrations and can be used for combustion control. The AV550G features a large 5.7-inch touch screen LCD with excellent operability for settings, calibrations, and trend graph viewing. The AV550G is ideal for combustion control in large utility boilers and various types of industrial furnaces.

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OX400 Low Concentration Zirconia Oxygen Analyzer

The OX400 is a highly accurate and reliable low-concentration zirconia oxygen analyzer that is capable of measuring a wide range of concentrations, from 0-10 ppm up to 0-100 vol%O2. A proprietary new thin-film deposition technology was used in the zirconia sensor that creates a molecular bond between the zirconia element and the platinum layer. This prevents separation, enables a reduction in sensor size and ensures a high-speed response and long life. The OX400 can be used to control and monitor various semiconductor applications, and to control environment, air leakage into inert gas, and other processes.

Paramagnetic Oxygen Analyzers

MG8G Paramagnetic Oxygen Analyzer (General Purpose Type)

The MG8G paramagnetic oxygen analyzer is a highly sensitive measurement instrument with excellent operability and reliability and measures the oxygen concentration of flammable gas mixtures. The sensor has a totally new architecture with a magnetic proportional flow rate system whose development was based on our long and field-proven experience. A clean auxiliary gas (N2), not process gas, flows past the detection unit sensor. Therefore, a stabilized output that is not influenced by contamination from process or other corrosive gases can be obtained for long periods. With no moving parts, the instrument is highly quake and shock resistant. The interference-gas compensation function ensures accurate measurement even in gases that exhibit a magnetic susceptibility, such as flammable gases.

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MG8E Paramagnetic Oxygen Analyzer (Flameproof Type)

The MG8E paramagnetic oxygen analyzer is a highly sensitive measurement instrument with excellent operability and reliability and measures the oxygen concentration of flammable gas mixtures. The analyzer is of flameproof construction and the sensor has a totally new architecture with a magnetic proportional flow rate system whose development was based on our long and field-proven experience. A clean auxiliary gas (N2), not process gas, flows past the detection unit sensor. Therefore, a stabilized output that is not influenced by contamination from process or other corrosive gases can be obtained for long periods. With no moving parts, the instrument is highly quake and shock resistant. The interference-gas compensation function ensures accurate measurement even in gases that exhibit a magnetic susceptibility, such as flammable gases. Highly stable indications at near the zero point make the MG8E suitable for low-concentration measurements such as in safety control.

Current Limit Type Oxygen Analyzers

OX100 Current Limit Type Oxygen Analyzer

The OX100 is a current limit type oxygen analyzer that is ideal for monitoring the oxygen concentration of ambient gases in production processes for semiconductors and electronic components, such as globe boxes, and for monitoring oxygen deficiency in clean rooms. It provides highly stable and accurate measurements for long periods, is easy to operate, and has a compact design, which make it suitable for integration into systems. A measuring range between 0 and 1000 ppm or between 0.1 and 25% can be manually selected. A dedicated sampling unit is available for measurements where the sample gas contains a small amount of organic gases.

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OX102 Enhanced Oxygen Analyzer

The OX102 is a current limit type oxygen analyzer that is ideal for monitoring the oxygen concentration of ambient gases in production processes for semiconductors and electronic components, such as globe boxes, and at nitrogen reflow furnaces. It provides highly stable and accurate measurements for long periods, is easy to operate, and has a compact design, which make it suitable for integration into systems. The measuring range can be switched automatically, remotely, or manually to 0 to 100 ppm, 0 to 1000 ppm, 0 to 10000 ppm, or 0 to 25%. A dedicated sampling unit is available for measurements where the sample gas contains a small amount of organic gases.

Zirconia High Temperature Humidity Analyzers

ZR402G/ZR22G Separate Type Zirconia High Temperature Humidity Analyzer

The ZR402G humidity analyzer features a touch screen LCD with excellent operability for settings, calibrations, and trend graph viewing. The probe uses a highly reliable zirconia sensor and a field-replaceable heater assembly. The analyzer does not require a sampling system, and is able to continuously measure the humidity of high temperature air. It is ideal for monitoring and controlling humidity in steam and electric dryers as well as humidifiers used in various industries.

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ZR202G Integrated Type Zirconia High Temperature Humidity Analyzer

The ZR202G humidity analyzer features an integrated probe and converter. The probe uses a highly reliable zirconia sensor and a field-replaceable heater assembly. The converter has infrared switches, allowing a user to operate the instrument without opening the cover in the field.

The ZR202G does not require a sampling system, and is able to continuously measure the humidity of high temperature air. It is ideal for monitoring and controlling humidity in steam and electric dryers as well as humidifiers used in various industries.

Oxygen Analyzer Types

Today's oxygen analyzers use one of a several types of oxygen sensors. As industrial process applications call for improved measurement accuracy and repeatability, users of oxygen analyzers are also demanding oxygen analyzers that require a minimum of maintenance and calibration. To this end, users of oxygen analyzers are encouraged to evaluate the merits of a particular oxygen sensor type in context to the application for which it is intended. There is no one universal oxygen analyzer type. The synoptic review of the various gas phase oxygen sensors provided below should be used in conjunction with information gathered from manufacturers of oxygen analyzers. This combination will help to ensure the selection of the right sensor type for the application under consideration. Ambient Temperature-Oxygen Analyzer Electrochemical-Oxygen Analyzer Paramagnetic-Oxygen Analyzer Polarographic-Oxygen Analzyer Zirconium Oxide-Oxygen Analyzer Oxygen Analyzer with Ambient Temperature Electrochemical Oxygen Sensors. Electrochemical-Oxygen Analyzer: The ambient temperature electrochemical sensor, often referred to as a galvanic sensor, is typically a small, partially sealed, cylindrical device (1-1/4” diameter by 0.75” height) that contains two dissimilar electrodes immersed in an aqueous electrolyte, commonly potassium hydroxide. As oxygen molecules diffuse through a semi-permeable membrane installed on one side of the sensor, the oxygen molecules are reduced at the cathode to form a positively charge hydroxyl ion. The hydroxyl ion migrates to the sensor anode where an oxidation reaction takes place. The resultant reduction/oxidation reaction generates an electrical current proportional to the oxygen concentration in the sample gas. The current generated is both measured and conditioned with external electronics and displayed on a digital panel meter either in percent or parts per million concentrations. With the advance in mechanical designs, refinements in electrode materials, and enhanced electrolyte formulations, the galvanic oxygen sensor provides extended life over earlier versions, and are recognized for their accuracy in both the percent and traces oxygen ranges. Response times have also been improved. A major limitation of ambient temperature electrochemical sensors is their susceptibility to damage when used with samples containing acid gas species such as hydrogen sulfide, hydrogen chloride, sulfur dioxide, etc. Unless the offending gas constituent is scrubbed prior to analysis, their presence will greatly shorten the life of the sensor. The galvanic sensor is also susceptible to over pressurization. For oxygen analyzer applications where the sample pressure is > 5 psig, a pressure regulator or control valve is normally recommended. Ambient Temperature-Oxygen Analyzer Electrochemical-Oxygen Analyzer Paramagnetic-Oxygen Analyzer Polarographic-Oxygen Analzyer Zirconium Oxide-Oxygen Analyzer Paramagnetic Oxygen Analyzer Within this category, the magnetodynamic or `dumbbell' type of design is the predominate sensor type. Oxygen has a relatively high magnetic susceptibility as compared to other gases such as nitrogen, helium, argon, etc. and displays a paramagnetic behavior. The paramagnetic oxygen sensor consists of a cylindrical shaped container inside of which is placed a small glass dumbbell. The dumbbell is filled with an inert gas such as nitrogen and suspended on a taut platinum wire within a non-uniform magnetic field. The dumbbell is designed to move freely as it is suspended from the wire. When a sample gas containing oxygen is processed through the sensor, the oxygen molecules are attracted to the stronger of the two magnetic fields. This causes a displacement of the dumbbell which results in the dumbbell rotating. A precision optical system consisting of a light source, photodiode, and amplifier circuit is used to measure the degree of rotation of the dumbbell. In some paramagnetic oxygen sensor designs, an opposing current is applied to restore the dumbbell to its normal position. The current required to maintain the dumbbell in it normal state is directly proportional to the partial pressure of oxygen and is represented electronically in percent oxygen. There are design variations associated with the various manufacturers of magnetodynamic paramagnetic oxygen analyzer types. Also, other types of sensors have been developed that use the susceptibility of oxygen to a magnetic field which include the thermomagnetic or `magnetic wind' type and the magnetopneumatic sensor. In general, paramagnetic oxygen sensors offer very good response time characteristics and use no consumable parts, making sensor life, under normal conditions, quite good. It also offers excellent precision over a range of 1% to 100% oxygen. The magnetodynamic sensor is quite delicate and is sensitive to vibration and/or position. Due to the loss in measurement sensitivity, in general, the paramagnetic oxygen sensor is not recommended for trace oxygen measurements. Other gases that exhibit a magnetic susceptibility can produce sizeable measurement errors. Manufacturers of the paramagnetic oxygen analyzer should provide details on these interfering gases. Ambient Temperature-Oxygen Analyzer Electrochemical-Oxygen Analyzer Paramagnetic-Oxygen Analyzer Polarographic-Oxygen Analzyer Zirconium Oxide-Oxygen Analyzer Polarographic Oxygen Analyzer The oxygen analyzer that features a polarographic oxygen sensor is often referred to as a Clark Cell [J. L. Clark (1822- 1898)]. In this type of sensor, both the anode (typically silver) and cathode (typically gold) are immersed in an aqueous electrolyte of potassium chloride. The electrodes are separated from the sample by a semi-permeable membrane that provides the mechanism to diffuse oxygen into the sensor. The silver anode is typically held at a potential of 0.8V (polarizing voltage) with respect to the gold cathode. Molecular oxygen is consumed electrochemically with an accompanying flow of electrical current directly proportional to the oxygen concentration based on Faraday's law. The current output generated from the sensor is measured and amplified electronically to provide a percent oxygen measurement. One of the advantages of the polarographic oxygen sensor is that while inoperative, there is no consumption of the electrode (anode). Storage times are almost indefinite. Similar to the galvanic oxygen sensor, they are not position sensitive. Because of the unique design of the polarographic oxygen sensor, it is the sensor of choice for dissolved oxygen measurements in liquids. For gas phase oxygen measurements, the polarographic oxygen analyzer type is suitable for percent level oxygen measurements only. The relatively high sensor replacement frequency is another potential drawback, as is the issue of maintaining the sensor membrane and electrolyte. A variant to the polarographic Oxygen Analyzer is what some manufacturers refer to as as oxygen analyzer that uses a non-depleting coulometric sensor where two similar electrodes are immersed in an electrolyte consisting of potassium hydroxide. Typically, an external EMF of 1.3 VDC is applied across both electrodes which acts as the driving mechanism for reduction/oxidation reaction. The electrical current resulting from this reaction is directly proportional to the oxygen concentration in the sample gas. As is the case with other sensor types, the signal derived from the sensor is amplified and conditioned prior to displaying. Unlike the conventional polarographic oxygen sensor, this type of sensor can be used for both percent and trace oxygen measurements. However, unlike the zirconium oxide, one sensor cannot be used to measure both high percentage levels as well as trace concentrations of oxygen. One major advantage of this sensor type is its ability to measure parts per billion levels of oxygen. The sensors are position sensitive and replacement costs are quite expensive, in some cases, paralleling that of an entire oxygen analyzer of another sensor type. They are not recommended for applications where oxygen concentrations exceed 25%. Ambient Temperature-Oxygen Analyzer Electrochemical-Oxygen Analyzer Paramagnetic-Oxygen Analyzer Polarographic-Oxygen Analzyer Zirconium Oxide-Oxygen Analyzer Zirconium Oxide Oxygen Analyzer The type of oxygen analyzer that uses this type of oxygen sensor is occasionally referred to as the “high temperature” electrochemical sensor and is based on the Nernst principle [W. H. Nernst (1864-1941)]. Zirconium oxide sensors use a solid state electrolyte typically fabricated from zirconium oxide stabilized with yttrium oxide. The zirconium oxide probe is plated on opposing sides with platinum which serves as the sensor electrodes. For a zirconium oxide sensor to operate properly, it must be heated to approximately 650 degrees Centigrade. At this temperature, on a molecular basis, the zirconium lattice becomes porous, allowing the movement of oxygen ions from a higher concentration of oxygen to a lower one, based on the partial pressure of oxygen. To create this partial pressure differential, one electrode is usually exposed to air (20.9% oxygen) while the other electrode is exposed to the sample gas. The movement of oxygen ions across the zirconium oxide produces a voltage between the two electrodes, the magnitude of which is based on the oxygen partial pressure differential created by the reference gas and sample gas. The zirconium oxide oxygen sensor exhibits excellent response time characteristics. Another virtue is that the same sensor can be used to measure 100% oxygen, as well as parts per billion concentrations. Due to the high temperatures of operation, the life of the sensor can be shortened by on/off operation. The coefficients of expansions associated with the materials of construction are such that the constant heating and cooling often causes “sensor fatigue”. A major limitation of the zirconium oxide oxygen analyzer is their unsuitability for trace oxygen measurements when reducing gases (hydrocarbons of any species, hydrogen, and carbon monoxide) are present in the sample gas. At operating temperatures of 650 degrees Centigrade, the reducing gases will react with the oxygen, consuming it prior to measurement thus producing a lower than actual oxygen reading. The magnitude of the error is proportional to the concentration of reducing gas. The zirconium oxide oxygen analyzer is the “defacto standard” for in-situ combustion control applications. Other types of oxygen analyzer types under development and in some cases being used for specific applications. They include, but are not limited to, luminescence polarization, opto-chemical sensors, laser gas sensors, et al. As these techniques are further developed and improved, they may represent viable alternatives to the existing technologies used in today's oxygen analyzer. Key words-Oxygen Analyzer-Trace Oxygen Analyzer -Percent Oxygen Analyzer - PPM Oxygen Analyzer - Percent Oxygen Analyzer - Industrial Oxygen Analyzer - Medical Oxygen Analyzer - Diving Oxygen Analyzer -Zirconium