Calibration of effective optical path length for hollow-waveguide based gas cell using absorption spectroscopy

2016 ◽  
Author(s):  
Lin Liu ◽  
Zhenhui Du ◽  
Jinyi Li
Keyword(s):  
Absorption Spectroscopy ◽  
Path Length ◽  
Optical Path Length ◽  
Optical Path ◽  
Hollow Waveguide ◽  
Gas Cell ◽  
Effective Optical Path Length

Integrating sphere effective optical path length calibration by gas absorption spectroscopy

2013 ◽  
Vol 114 (3) ◽  
pp. 341-346 ◽  
Author(s):  
Qiang Gao ◽  
Yungang Zhang ◽  
Jia Yu ◽  
Zhiguo Zhang ◽  
Shaohua Wu ◽  
...  
Keyword(s):  
Absorption Spectroscopy ◽  
Path Length ◽  
Optical Path Length ◽  
Optical Path ◽  
Gas Absorption ◽  
Integrating Sphere ◽  
Effective Optical Path Length

scholarly journals Optical Path Length Calibration: A Standard Approach for Use in Absorption Cell-Based IR-Spectrometric Gas Analysis

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Javis Anyangwe Nwaboh ◽  
Oliver Witzel ◽  
Andrea Pogány ◽  
Olav Werhahn ◽  
Volker Ebert
Keyword(s):  
Absorption Spectroscopy ◽  
Path Length ◽  
Line Strength ◽  
Optical Path Length ◽  
Comparison Method ◽  
Optical Path ◽  
Infrared Light ◽  
Strength Parameter ◽  
Gas Cell ◽  
System Of Units

We employed a comparison method to determine the optical path length of gas cells which can be used in spectroscopic setup based on laser absorption spectroscopy or FTIR. The method is based on absorption spectroscopy itself. A reference gas cell, whose length is a priori known and desirably traceable to the international system of units (SI), and a gas mixture are used to calibrate the path length of a cell under test. By comparing spectra derived from pressure-dependent measurements on the two cells, the path length of the gas cell under test is determined. The method relies neither on the knowledge of the gas concentration nor on the line strength parameter of the probed transition which is very rarely traceable to the SI and of which the uncertainty is often relatively large. The method is flexible such that any infrared light source and infrared active molecule with isolated lines can be used. We elaborate on the method, substantiate the method by reporting results of this calibration procedure applied to multipass and single pass gas cells of lengths from 0.38 m to 21 m, and compare this to other methods. The relative combined uncertainty of the path length results determined using the comparison method was found to be in the ±0.4% range.

Interchangeable Range of Ozone Concentration Simulation for Low Cost Reconfigurable Brass Gas Cell

2014 ◽  
Vol 69 (8) ◽  
Author(s):  
Tay Ching En Marcus ◽  
Michael David ◽  
Maslina Yaacob ◽  
Mohd Rashidi Salim ◽  
Mohd Haniff Ibrahim ◽  
...  
Keyword(s):  
Theoretical Calculation ◽  
Ozone Concentration ◽  
Path Length ◽  
Low Cost ◽  
Cell Structure ◽  
Optical Path Length ◽  
Optical Path ◽  
Concentration Measurement ◽  
Gas Cell ◽  
Wide Range

Ultraviolet absorption spectroscopy is reliable for ozone concentration measurement. Concentration range and optical path length are inversely related based on theoretical calculation and observation of previous work. However, gas cells for ozone application are typically not expandable. In addition, they incur cost for custom fabrication. Here we design a reconfigurable brass gas cell that may interchange optical path length between 5.6 cm and 10.8 cm. Components are available at low cost, easy to joint and ready to use. Theoretical background and gas cell structure are discussed. Practical transmittance values between e-0.65 and e-0.05 are proposed for theoretical calculation of concentration via Beer-Lambert law. The concentration values are used in SpectralCalc.com gas cell simulation to obtain transmittance. Both approaches yield comparable result. Simulation result shows concentration range of 5.6 cm optical path length gas cell (31.82 ppm to 413.67 ppm) is wider than concentration range of 10.8 cm optical path length gas cell (16.50 ppm to 214.49 ppm). Simulation condition is at transmittance from 0.5291 to 0.9522, sampling wavelength 253.65 nm, temperature 300 K and pressure 1 atm. Thus, we strongly recommend short optical path length gas cell (5.6 cm) for wide range of concentration measurement (31.82 ppm to 413.67 ppm).

Effective optical path length investigation for cubic diffuse cavity as gas absorption cell

2013 ◽  
Vol 116 (1) ◽  
pp. 135-140 ◽  
Author(s):  
Jia Yu ◽  
Fu Zheng ◽  
Qiang Gao ◽  
Yinjie Li ◽  
Yungang Zhang ◽  
...  
Keyword(s):  
Path Length ◽  
Optical Path Length ◽  
Optical Path ◽  
Gas Absorption ◽  
Absorption Cell ◽  
Effective Optical Path Length

Doubled Optical Path Length for Photonic Bandgap Fiber Gas Cell Using Micromirror

2011 ◽  
Vol 50 (6) ◽  
pp. 06GM01 ◽  
Author(s):  
Xuefeng Li ◽  
Jinxing Liang ◽  
Hiroshi Oigawa ◽  
Toshitsugu Ueda
Keyword(s):  
Path Length ◽  
Photonic Bandgap ◽  
Optical Path Length ◽  
Optical Path ◽  
Gas Cell ◽  
Photonic Bandgap Fiber

Incident Angle Approach to Sensitivity Enhancement for Ozone Sensor

2015 ◽  
Vol 735 ◽  
pp. 255-259
Author(s):  
Michael David ◽  
Tay Ching En Marcus ◽  
Maslina Yaacob ◽  
Mohd Rashidi Salim ◽  
Nabihah Hussin ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Light Source ◽  
Path Length ◽  
Incident Angle ◽  
Optical Path Length ◽  
Sensitivity Enhancement ◽  
Optical Path ◽  
Internal Diameter ◽  
Gas Cell ◽  
Optical Gas Sensor

The design and mathematical model of a reflective type optical gas sensor is presented. Light source is radiated at an incident angle for 10 cm gas cell with an internal diameter of 0.4 cm. At an incident angle of 1o, optical path length obtained is 342.7886 cm, at 27o incident angle, optical path length is 10.4926 cm and at an incident angle of 28o, optical path length is 9.9631 cm. The model is most efficient at lower incident angles, precisely between (1o and 27o). Effects of variation in diameter and length of gas cell are also demonstrated.

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