Analytical Instrumentation

6 Factors to Consider When Choosing an Oxygen Analyzer for your Application

  • We explored the fundamental concepts of the many technologies used in gas analysis to measure the concentration of oxygen in gas mixtures in our earlier article, “How an oxygen analyzer works.” .
  • Let’s analyze the important factors to take into account while choosing the best oxygen analyzer for your particular application.
6 Factors to Consider When Choosing an Oxygen Analyzer for your Application 1
  • The concentration of oxygen in the gas mixture to be analyzed must be taken into account when choosing an oxygen analyzer. 
  • This will determine the technology selection in significant part, in addition to the necessary measurement performance. 
  • To ensure precise and dependable measurement performance, you can choose the most suitable technology by being aware of the particular oxygen concentration levels involved in your application.

Here’s a thorough explanation of each option:

  • When measuring in parts per million (ppm), gas chromatography may be required for extremely low oxygen levels. 
  • For identifying levels of oxygen in a gas mixture, this approach provides excellent sensitivity and precision.
  • These instruments can measure low oxygen levels with accuracy, but they are mainly utilized for higher oxygen concentrations. 
  • They can be used for measurements at the ppm level and have a quite decent performance.
  • Although they are more frequently utilized for higher concentration ranges, zirconia analyzers can also be used for low oxygen concentrations. 
  • Depending on the particular model and configuration, their low-level performance may differ.
  • Even at low oxygen levels, laser analyzers, especially those with modern technology included, can produce accurate results. 
  • They are appropriate for accurate analysis in ppm ranges because of their excellent resolution and calibration stability.
  • For the measurement of oxygen concentrations in the range of 1% to 21% or more, magnetic analyzers are often preferred. 
  • They are perfect for a variety of industrial applications because of their exceptional accuracy and reliability.

Click here to know more about Working Principle of Paramagnetic O2 Analyzers 

  • Gas Chromatography: High sensitivity for trace oxygen levels.
  • Electrochemical Analyzers: Suitable for both low and moderate oxygen concentrations.
  • Zirconia Analyzers: Adaptable, with uses in a range of concentrations.
  • Paramagnetic Analyzers: Highly accurate and reliable for moderate to high oxygen levels.
  • Laser Analyzers: Excellent stability and resolution, perfect for accurate readings across a wide concentration range.
6 Factors to Consider When Choosing an Oxygen Analyzer for your Application 2
  • Apart from the oxygen concentration, the overall composition of the gas mixture being analyzed plays a critical role in selecting the appropriate oxygen analyzer.
  • By considering the overall composition of the gas mixture and the specific challenges posed by different environments, Whether it’s ensuring compatibility with sulfur compounds, mitigating safety risks in flammable environments, or handling corrosive gasses and solid particles, choosing the right analyzer is essential for accurate and reliable gas analysis.

Here’s a detailed look at how different analyzer technologies respond to different gas matrix compositions:

  • The capacity of laser and magnetic analyzers to produce precise measurements independent of the gas composition is well known. This qualifies them for a wide range of applications where the composition of the gas mixture may differ significantly.
  • Due to their independence from the gas matrix, paramagnetic and laser analyzers can reliably analyze gas mixtures containing different compounds without compromising measurement accuracy.
  • Zirconia analyzers may not be ideal for gas mixtures containing sulfur compounds or in flammable environments. Sulfur compounds can degrade the zirconia sensor prematurely, while flammable environments pose a safety risk.
  • When selecting a zirconia analyzer, it’s essential to assess the composition of the gas mixture and ensure compatibility with the analyzer’s specifications. Alternative technologies may be more suitable for applications involving sulfur compounds or flammable gasses.
  • For corrosive gas mixes, laser analyzers are recommended, particularly the in situ cross-stack type. Accurate analysis is possible in these arrangements because the analyzer is placed directly in the gas stream, away from corrosive gasses.
  • Industries dealing with corrosive gasses, such as chemical processing or wastewater treatment plants, benefit from the corrosion-resistant design of in situ cross-stack laser analyzers.
  • Conventional analyzers face difficulties in environments with a high concentration of solid particles. In such cases, specialized laser or paramagnetic analyzers equipped to handle particulate matter are required.
  • In situations with high solid particle concentration, analyzers equipped with characteristics like advanced filtration mechanisms or strong sample handling systems are crucial for accurate results.

Understanding the installation restrictions and environmental factors unique to your application is essential when choosing an oxygen analyzer. The choice between an in situ or extractive analyzer depends on a number of criteria, such as available space, vibrations, temperature changes, explosive zones, and magnetic fields.

  • In Situ Analyzers are suitable for confined areas and are directly integrated into the gas stream, while Extractive Analyzers demand more space due to the necessity of sample extraction and a separate analyzer unit.
  • Industrial vibrations can compromise accuracy; therefore, analyzers should be placed in areas with minimal vibration. 
  • Mounting considerations such as vibration-isolated mounts or shock-absorbing brackets can be utilized to mitigate the effects of vibrations.
  • Positioning analyzers in environments with stable temperatures is crucial as temperature fluctuations can affect performance. 
  • Some analyzers feature temperature compensation capabilities for consistent readings despite temperature changes.
  • In hazardous environments prone to explosive gasses or vapors, analyzers compliant with safety regulations should be installed. 
  • Implementing explosion-proof enclosures is essential to prevent ignition and ensure operational safety.
  • Nearby magnetic fields may disrupt analyzer operation; therefore, analyzers should be shielded or isolated to minimize magnetic interference.
  • The choice between In Situ and Extractive analyzers depends on factors such as space availability, environmental conditions, and specific measurement requirements. 
  • In situ analyzers are suited for restricted spaces, while extractive analyzers are preferable in challenging environments.
  • The availability of utilities on-site is a crucial consideration when selecting an oxygen analyzer. 
  • Different analyzer technologies have varying requirements for power supply, calibration gasses, reference gasses, and purge gasses. 
  • All oxygen analyzers require a compatible power supply, considering voltage and frequency requirements. 
  • Analyzers can generally use either alternating current (AC) or direct current (DC) power.
  • Zero Calibration Gas: Typically nitrogen, used for zero calibration to establish the baseline reading.
  • Span Calibration Gas: Oxygen gas, commonly used for span calibration to set the upper range of measurement. Ensure high-purity calibration gasses free from contaminants that could affect accuracy.
  • Some analyzers, especially those with micro mass flow meters, may require a reference gas like nitrogen  to ensure accuracy and stability. 
  • It should meet analyzer requirements and be easily accessible for stabilization, calibration and maintenance.
  • Certain analyzers, like laser analyzers, may need purge gas to maintain optimal performance and cleanliness of optical components. 
  • Types include air or nitrogen, depending on analyzer and process conditions. Ensure a continuous supply to prevent contamination and ensure uninterrupted operation.
  • Conduct a thorough assessment of on-site utility availability before installation to ensure compatibility. 
  • Plan the installation carefully to provide easy access to utilities and minimize interference or contamination risks.
  • Budget considerations are very important in the selection of an oxygen analyzer for your application. 
  • While the initial purchase cost is a significant factor, it’s essential to evaluate the long-term operating expenses to determine the most cost-effective solution. 
  • Balancing budget considerations with performance requirements is essential for selecting the right oxygen analyzer technology, whether prioritizing upfront savings or long-term reliability.
  • Different analyzer technologies have varying upfront costs. Electrochemical and zirconia analyzers typically have lower initial purchase costs compared to laser analyzers.
  • Consider the allocated budget for purchasing the analyzer equipment and ensure it aligns with the required capabilities and features.
  • Maintenance Requirements: Analyzers with lower initial costs may incur higher operating expenses due to ongoing maintenance like sensor replacement, calibration, and servicing.
  • Despite higher upfront costs, laser analyzers offer long-term savings due to reduced calibration needs, enhancing stability and reliability.
  • Evaluate the total cost of ownership over the equipment’s lifespan, including both purchase and operating costs, for a clearer economic picture.
  • Despite higher initial costs, laser analyzers may yield long-term savings due to reduced maintenance and calibration needs.
  •  Consider factors such as increased efficiency and improved process control when evaluating Return on Investment  for each analyzer technology.
  •  Allocate funds not only for initial purchase but also for ongoing maintenance, calibration, and servicing requirements.
  •  Factor in warranty coverage, service agreements, and spare parts availability when assessing the financial viability of different analyzer options.
  • This will influence the choice of analyzer technology and configuration. 
  • For example, extractive analyzers are better suited for high flow rates, while in-situ analyzers can be used for low flow rates.
  • Consider how the analyzer data will be collected and used. Some analyzers have built-in data loggers or communication interfaces, while others require additional equipment.
  • Depending on your application, there may be specific regulations or certifications that the analyzer must comply with.
  • Ensure that you have access to qualified personnel who can install, operate, and maintain the analyzer.

Click here to carry out 10 Step Oxygen Analyzer Calibration Procedure: Paramagnetic Type

Choose the right oxygen analyzer effortlessly with our complete checklist tailored to your application needs.

6 Factors to Consider When Choosing an Oxygen Analyzer for your Application 3

Access our user-friendly checklist for oxygen analyzer selection, available for download in Excel format for your convenience

Checklist for Choosing an Oxygen Analyzer for Your Application – Download

Click here for Step by Step Preventive Maintenance Procedure for O2 Analyzers : Paramagnetic Type

Click here to download the Checklist to carry out Step by Step Preventive Maintenance 

Sundareswaran Iyalunaidu

With over 24 years of dedicated experience, I am a seasoned professional specializing in the commissioning, maintenance, and installation of Electrical, Instrumentation and Control systems. My expertise extends across a spectrum of industries, including Power stations, Oil and Gas, Aluminium, Utilities, Steel and Continuous process industries. Tweet me @sundareshinfohe

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