Understanding the technical language used in gas analysis and TDLAS (Tunable Diode Laser Absorption Spectroscopy) technology is crucial for professionals in the field. This glossary provides definitions for key terms to help you better grasp the concepts and terminology related to gas analysis and TDLAS.
Absorption Spectrum
The range of wavelengths (or frequencies) over which a gas absorbs light. Each gas has a unique absorption spectrum that acts as a fingerprint for its identification.
Accuracy
The degree to which the measured value of a gas concentration matches the actual concentration. High accuracy is crucial for reliable gas analysis.
Calibration
The process of setting and verifying the accuracy of a gas analyzer using known reference standards. Regular calibration ensures the analyzer provides accurate and reliable measurements.
Continuous Emission Monitoring Systems (CEMS)
Systems used to continuously collect and analyze data on gas emissions from industrial processes, ensuring compliance with environmental regulations.
Detection Limit
The lowest concentration of a gas that can be reliably detected by a gas analyzer. TDLAS technology is known for its low detection limits, making it highly sensitive.
Diode Laser
A semiconductor device that emits a narrow beam of light at specific wavelengths when an electric current passes through it. Tunable diode lasers are used in TDLAS for their ability to precisely target specific gas absorption lines.
Emission Control
The practice of monitoring and reducing the release of harmful gases and pollutants from industrial processes to comply with environmental regulations and protect public health.
Environmental Monitoring
The process of measuring and analyzing environmental parameters, such as air and water quality, to assess and manage the impact of human activities on the environment.
Gas Cell
A component of a gas analyzer where the gas sample is contained and exposed to the laser light. The interaction between the gas and the light is measured to determine gas concentrations.
Gas Chromatography (GC)
A common analytical method for separating and analyzing compounds in a gas mixture. Unlike TDLAS, GC requires sample preparation and has longer analysis times.
Interference
The effect of other gases or substances that can affect the accuracy of gas measurements. TDLAS technology minimizes interference by selectively targeting specific gas absorption lines.
Laser Absorption Spectroscopy
A technique for measuring gas concentrations based on the absorption of laser light by gas molecules. TDLAS is a type of laser absorption spectroscopy.
Leak Detection and Repair (LDAR)
Programs designed to identify and repair leaks of hazardous gases in industrial facilities, ensuring safety and regulatory compliance.
Linewidth
The width of the spectral line emitted by a laser. Narrow linewidths are desirable in TDLAS for high-resolution measurements and selectivity.
Molar Absorptivity (ε)
A constant that indicates how strongly a gas absorbs light at a specific wavelength. It is used in the Beer-Lambert Law to calculate gas concentrations.
Path Length (L)
The distance the laser light travels through the gas sample in the gas cell. The path length affects the sensitivity of the measurement.
Photodetector
A device that converts light into an electrical signal, used in TDLAS gas analyzers to measure the intensity of transmitted or absorbed light.
Precision
The degree to which repeated measurements under unchanged conditions produce the same results. High precision indicates reliability and consistency in gas analysis.
Real-Time Monitoring
The continuous measurement and analysis of gas concentrations as they occur, allowing for immediate detection and response to changes or leaks.
Selectivity
The ability of a gas analyzer to target and measure specific gases in the presence of other gases. TDLAS offers high selectivity by tuning the laser to specific absorption lines.
Sensitivity
The ability of a gas analyzer to detect low concentrations of gases. TDLAS is known for its high sensitivity, making it suitable for trace gas analysis.
Signal-to-Noise Ratio (SNR)
A measure of the strength of the signal relative to the background noise. A high SNR indicates a clear and accurate measurement.
Tunable Diode Laser Absorption Spectroscopy (TDLAS)
A gas analysis technique that uses tunable diode lasers to measure gas concentrations based on the absorption of specific wavelengths of light by gas molecules.
Volatile Organic Compounds (VOCs)
A group of organic chemicals that are significant air pollutants, often monitored in industrial emissions using TDLAS gas analyzers.
Wavelength Modulation Spectroscopy (WMS)
A technique used in TDLAS to enhance sensitivity and reduce noise by modulating the wavelength of the laser light.
Zero Calibration
A calibration process where the gas analyzer is set to a known zero point using a gas sample that contains no detectable levels of the target gas.
Compliance
The adherence to environmental regulations and standards regarding emissions and pollutants. TDLAS technology aids in maintaining compliance by providing accurate and real-time data.
