Beer-Lambert law
Beer-Lambert's law is the basis for optical quantitative analysis of matter concentration, and characterizes the absorption of light by a substance at a specific wavelength. As can be seen, in the case where the absorption cross section and the optical path length are known, the concentration of the corresponding gas can be calculated by measuring the incident light intensity and the exit light intensity.
I0 (λ)---- incident light intensity of the light with a wavelength of λ;
I(λ)---- exit light intensity of the light with a wavelength of λ;
σ(λ)---- absorption cross section of the gas at the wavelength of λ;
C---- concentration of the gas to be measured;
L----action length of gas and light (effective length of gas pool);
UV absorption cross section of SO2 , NO and other gases
SO2 and NO have obvious characteristic absorption spectral lines in the range of 200-320 nm, so it is very suitable to simultaneously measure these two gases by ultraviolet spectrometry.
DOAS
DOAS is the English abbreviation for differential optical absorption spectroscopy. The basic principle is to distinguish and invert the concentration of the gas to be measured by using the narrow-band absorption characteristics of the molecules of the substance to be measured.
The absorption of light by the sample gas can be divided into two parts: one part changes rapidly with the wavelength, and forms a narrow-band fine structure of the spectrum, which is only related to the characteristic absorption of the gas to be measured; the other part changes slowly with the wavelength, and forms a broad-band structure of the spectrum, which is further related to impurity scattering in the sample gas and other factors in addition to the characteristics of partial gas.
DOAS technique separates the narrow-band absorption portion of the absorption spectrum, thereby avoiding the effects of slow absorption of dust and other gases.
Optical path structure
The optical path structure of the instrument is shown in the figure below: the ultraviolet light emitted by the ultraviolet light source enters the gas pool after being collimated by the collimating lens, and the ultraviolet light absorbed by the sample gas is focused by the focusing lens, coupled into the optical fiber and transmitted to the spectrometer. After grating splitting and CCD receiving optical signals for photoelectric conversion, the ultraviolet absorption spectrum of the gas to be measured is obtained. Finally, the concentration value of the gas to be measured is inverted by software algorithm.
GYPG-001 series gas analyzers
GYPG-001 series gas analyzers are gas analyzers independently developed by our company for environmental monitoring and industrial field exhaust gas analysis. The analyzer is intended to mainly measure concentrations of gases such as SO2, NOx and O2, and has the characteristics of high measurement accuracy, high stability and reliability, and short response time.
The product is mainly used in the following occasions:
- Manual detection of flue gas emission (analysis of SO2, NOx,O2)（analysis of SO2、NOx、O2）
- Desulfurization process detection （analysis of SO2、O2）
- Desulfurization process detection（analysis of NOx、NH3、O2）
- Waste incineration flue gas emission detection（analysis of SO2、NOx、O2）
It is especially suitable for environmental monitoring law enforcement and comparison, flue gas emission unit self-monitoring and third party commissioned detection.
Product Features
- SO2 and NOx are measured using UV differential spectroscopy. Compared with traditional NDIR, the measurement accuracy is immune to moisture and dust, and there is substantially no zero shift.
- Directly measure NO2 without NOx
- High-resolution spectrometer is used for spectral analysis, and the instrument has a low detection limit.
- The instrument has high internal temperature control accuracy and good environmental adaptability.
- The light source adopts deuterium lamp with high stability and the instrument has good stability.
- There are no optical moving parts such as cut-light wheels, filter wheels, interferometers, etc., and reliability is high.
- Modular design is employed for light source, spectrometer, core circuit, gas chamber, oxygen sensor, etc., and high reliability, good scalability and easy maintenance are realized.
Principle
Technical Parameters
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Range
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SO2
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0-100-2000mg/m3 (can be expanded)
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NO
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0-100-2000mg/m3 (can be expanded)
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NO2
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0-100-2000mg/m3 (can be expanded)
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O2
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0-25%
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Detection Limit
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SO2
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0.1mg/m3
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NO
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0.1mg/m3
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NO2
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0.4mg/m3
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Linearity
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±1%F.S.
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Repeatability
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1%.
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Zero Drift
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±0.5%F.S. (1 hour) @100mg/m3 range
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Span Drift
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±1%F.S. (1 hour) @100mg/m3 range
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Operating Temperature Range
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-10~35℃
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Response time
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20 seconds (1.5L/min)
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Interferences
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Less than ±1%F.S @100mg/m3 range
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Power Requirements
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220VAC, 500W(Max)
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Warm-up time
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≤ 30 minutes
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Flow Rate
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1.5L/min±0.5L/min
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Physical Dimensions
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590mm(D)x260mm(W)225mm(H)
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Weight
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15.20Kg
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Data Storage
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SD card, can be exported by U-disk
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Printer
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Mini thermal printer
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Certificate
