What Is a Gas Analyzer?
A Gas Analyzer is a device used to analyze the gaseous components of a substance.
The most common case is to measure the concentration of components in a gas. The target gases include carbon dioxide, carbon monoxide, oxygen, nitrogen oxides, and others. The types of gases that can be measured and the number of items vary greatly depending on the intended use.
In factories, they are used for monitoring air pollution and energy conservation. In addition, these instruments are used in a wide range of applications, such as in the agricultural field.
Uses of Gas Analyzers
Gas Analyzers are used in a variety of situations because they can measure multiple types of gases. The following are examples of applications of Gas Analyzers:
1. Environmental Monitoring
By monitoring the concentration of gas components in the air, it is possible to determine the status of air pollution and take appropriate measures. It measures the concentration of carbon dioxide, carbon monoxide, nitrogen oxides, sulfur oxides, and other gases.
Gas Analyzers used to measure factory exhaust gases are also called Exhaust Gas Analyzers. Exhaust gas analyzers are required to be installed in facilities that generate soot and smoke as specified in the Air Pollution Control Law, and are widely used for environmental monitoring.
2. Medical Care
Gas Analyzers are also used in medicine, mainly for the diagnosis and treatment of respiratory and metabolic diseases. They may measure the concentration of gas components in exhaled air in pulmonary function tests or in blood gas analysis.
Gas Analyzers for medical use are required to measure with high accuracy and are designed to be easily operated by medical personnel. Easy operability is especially important for use in emergencies and ambulances, where quick and accurate measurements are required.
3. Industrial Processes
Used for process control in chemical plants and manufacturing plants. The concentration of gas components in a reactor is measured for process optimization and quality control. In the food industry, it is also used to measure the concentration of gas components in the air inside packages to evaluate freshness and quality.
Principle of Gas Analyzer
There are several gases that can be measured by Gas Analyzers. As such, there are a wide variety of analysis methods. The following are examples of Gas Analyzer principles
1. Infrared Absorption Method
A sample is irradiated with light of a specific wavelength, and the amount of absorbed infrared radiation is detected by a mass flow sensor. There are double-beam and single-beam types depending on the type of irradiation. The double-beam method detects gas concentration by comparing a reference cell (blank) and a sample cell, while the single-beam method measures only the sample cell.
2. Thermal Conduction Method
This method utilizes the fact that when a platinum wire is heated and brought into contact with a sample gas, the equilibrium temperature between the supplied heat and the radiated heat depends on the thermal conductivity of each gas. It is simple in structure and can measure a variety of gases.
3. Magnetic Force Method
When a magnetic field is applied to a sample, pressure is generated as oxygen is attracted to it. This pressure is detected by the mass flow sensor. This method is mainly used to measure oxygen concentration.
The zirconia method also exists for measuring oxygen. This method uses the property of zirconia porcelain to conduct oxygen ions under high temperature. The oxygen concentration is determined by detecting the electromotive force generated at the electrodes of the zirconia element.
How to Select a Gas Analyzer
When selecting a Gas Analyzer, the choice should be based on the type of gas, detection sensitivity, and intended use. If your budget is limited, it is important to select a measuring instrument with the minimum necessary functions.
First, confirm the type of gas you wish to measure. The available Gas Analyzers differ depending on the gas composition. The principle is that there are various products as described in the above section, and the gas components that can be measured are different. You need to select the one that best suits your purpose.
Once the gas type is determined, check the detection sensitivity. If it cannot measure gas concentrations in the required range, it will not satisfy the application. If you are measuring a gas component with low concentration, you need to select a measuring instrument with high sensitivity.
It is also important to select a product based on the intended use. Since there are portable products and products for continuous measurement, selection should be based on the intended use.