Gas analyzers, as specialized equipment for detecting and analyzing the composition and concentration of gases, are widely used in various fields such as industrial production, environmental monitoring, scientific research experiments, and safety inspection. With continuous technological advancements, the types of gas analyzers have become increasingly diverse to meet the specific needs of different industries and scenarios. This article will detail several common types of gas analyzers and their applications.
Thermal conductivity gas analyzers operate on the principle that different gases have different thermal conductivity. They calculate the content of certain components by measuring the thermal conductivity of a gas mixture. These analyzers are simple in structure, provide accurate and reliable data, and can measure a wide variety of gases. They can be used to analyze not only low-concentration flammable gases such as hydrogen and methane, but also sulfur dioxide, carbon dioxide, ammonia, and many other gases. Furthermore, thermal conductivity gas analyzers can be used as detectors in chromatographs to analyze other components.
Electrochemical gas analyzers measure the composition and content of gases based on changes in current or the amount of conductive ions caused by chemical reactions in the gas. These analyzers typically employ a diaphragm structure to improve selectivity and prevent contamination of the measuring electrode surface. Common types of electrochemical gas analyzers include galvanic cell type and constant potential electrolytic type. Galvanic cell analyzers electrolyze the analyte gas diffused into the electrolyte through a diaphragm, and determine the concentration of the analyte gas by measuring the resulting electrolytic current. Potential-dependent electrolysis analyzers, on the other hand, apply a specific potential to electrodes, causing the analyte gas to electrolyze on the electrode surface. The electrolysis potential of the analyte gas is determined by measuring the potential applied to the electrodes.
Infrared Absorption Analyzers: Infrared absorption analyzers operate on the principle of selective absorption of infrared rays of different wavelengths by different gas components. Measuring this absorption spectrum can distinguish the type of gas, while measuring the absorption intensity can determine the concentration of the analyte gas. Infrared analyzers are highly sensitive, have a rapid response, can provide continuous online indication, and can also form an adjustment system. They can analyze not only gas composition but also solution composition and are widely used in industry, scientific research, and environmental protection.
Mass Spectrometers: Mass spectrometers are a more advanced gas analysis device. They utilize the different trajectories of different ions in an electric or magnetic field to separate ions according to their mass-to-charge ratio, obtaining a mass spectrum, thereby obtaining qualitative and quantitative results for the sample. Mass spectrometers can be categorized into several types based on the commonly used mass separators, including scanning magnetic fan mass spectrometers, quadrupole mass spectrometers, and time-of-flight mass spectrometers. Scanning magnetic fan mass spectrometers offer high stability and repeatability, making them suitable for industrial applications; while quadrupole mass spectrometers offer high sensitivity, making them more suitable for laboratories or scientific research. Mass spectrometers can analyze trace components in gases, such as rare gases in the air and trace elements in atmospheric pollutants.
Other Types of Gas Analyzers Besides the common gas analyzers mentioned above, there are other types, such as gas chromatographs, paramagnetic analyzers, and dew point analyzers. A gas chromatograph is a device that uses chromatographic separation technology for analysis; it can separate and detect complex components in gases. Paramagnetic analyzers feature fast response speeds and high measurement accuracy, and are often used for precise process control. Dew point analyzers are used to measure the moisture content in gases and are widely used in industries such as petrochemicals, natural gas, and industrial gases.
