Evaluation of CO2, water vapor, and their turbulent exchange rates with an airborne open-path infrared gas analyzer

1999 ◽  
Author(s):  
Werner K. Graber ◽  
Markus Furger
Keyword(s):  
Water Vapor ◽  
Exchange Rates ◽  
Turbulent Exchange ◽  
Gas Analyzer ◽  
Open Path ◽  
Infrared Gas Analyzer

scholarly journals Carbon Dioxide Capture Using a Zeolite Molecular Sieve Sampling System for Isotopic Studies (13C and 14C) of Respiration

Radiocarbon ◽  
2005 ◽  
Vol 47 (3) ◽  
pp. 441-451 ◽  
Author(s):  
S M L Hardie ◽  
M H Garnett ◽  
A E Fallick ◽  
A P Rowland ◽  
N J Ostle
Keyword(s):  
Mass Spectrometry ◽  
Molecular Sieve ◽  
Ecosystem Respiration ◽  
Isotope Ratio Mass Spectrometry ◽  
Gas Analyzer ◽  
Sampling System ◽  
Air Stream ◽  
Isotopic Studies ◽  
Isotope Studies ◽  
Infrared Gas Analyzer

A method for collecting an isotopically representative sample of CO2 from an air stream using a zeolite molecular sieve is described. A robust sampling system was designed and developed for use in the field that includes reusable molecular sieve cartridges, a lightweight pump, and a portable infrared gas analyzer (IRGA). The system was tested using international isotopic standards (13C and 14C). Results showed that CO2 could be trapped and recovered for both δ13C and 14C analysis by isotope ratio mass spectrometry (IRMS) and accelerator mass spectrometry (AMS), respectively, without any contamination, fractionation, or memory effect. The system was primarily designed for use in carbon isotope studies of ecosystem respiration, with potential for use in other applications that require CO2 collection from air.

scholarly journals Precise multispecies agricultural gas flux determined using broadband open-path dual-comb spectroscopy

2021 ◽  
Vol 7 (14) ◽  
pp. eabe9765
Author(s):  
Daniel I. Herman ◽  
Chinthaka Weerasekara ◽  
Lindsay C. Hutcherson ◽  
Fabrizio R. Giorgetta ◽  
Kevin C. Cossel ◽  
...  
Keyword(s):  
Ecological Monitoring ◽  
Trace Gas ◽  
Gas Analyzer ◽  
Gas Flux ◽  
Time Resolved ◽  
Trace Gas Emissions ◽  
Open Path ◽  
Statistical Precision ◽  
Methane Fluxes ◽  
Flux Quantification

Advances in spectroscopy have the potential to improve our understanding of agricultural processes and associated trace gas emissions. We implement field-deployed, open-path dual-comb spectroscopy (DCS) for precise multispecies emissions estimation from livestock. With broad atmospheric dual-comb spectra, we interrogate upwind and downwind paths from pens containing approximately 300 head of cattle, providing time-resolved concentration enhancements and fluxes of CH4, NH3, CO2, and H2O. The methane fluxes determined from DCS data and fluxes obtained with a colocated closed-path cavity ring-down spectroscopy gas analyzer agree to within 6%. The NH3 concentration retrievals have sensitivity of 10 parts per billion and yield corresponding NH3 fluxes with a statistical precision of 8% and low systematic uncertainty. Open-path DCS offers accurate multispecies agricultural gas flux quantification without external calibration and is easily extended to larger agricultural systems where point-sampling-based approaches are insufficient, presenting opportunities for field-scale biogeochemical studies and ecological monitoring.

Preparation of matched reagents for use with the Scholander gas analyzer

1977 ◽  
Vol 43 (1) ◽  
pp. 164-166
Author(s):  
R. G. Collins ◽  
V. W. Musasche ◽  
E. T. Howley
Keyword(s):  
Water Vapor ◽  
Vapor Pressure ◽  
Volume Change ◽  
Quantitative Method ◽  
Gas Analysis ◽  
Vapor Pressures ◽  
Gas Analyzer ◽  
Atmospheric Air ◽  
Fixed Acid

Scholander's method of gas analysis requires that the solutions for CO2 absorber, O2 absorber, and acid-rinse be matched in terms of water vapor tension throughout the analysis. Any difference in vapor pressure between either or both of the absorbing solutions and the indicator drop (composed of acid-rinse) will produce a measurable volume change which cannot be attributed to the presence of absorbable gases. This paper describes a practical and quantitative method for preparing reagents whose vapor pressures are matched. A fixed acid-rinse formulation was used throughout. A CO2 absorber prepared from 1.35 N KOH and an O2 absorber prepared from 0.76 N KOH were both matched in terms of vapor pressure with Scholander's acid-rinse solution. Analysis of atmospheric air provided a check on the accuracy of the technique. The values obtained were O2 20.94%, CO2 0.03%, and N2 (balance) 79.04%.

Application to Woody Plants of a Rapid Method for Determining Leaf CO2 Compensation Concentrations

1973 ◽  
Vol 3 (2) ◽  
pp. 237-242 ◽  
Author(s):  
D. I. Dickmann ◽  
D. H. Gjerstad
Keyword(s):  
Rapid Method ◽  
Woody Plants ◽  
Woody Species ◽  
Moisture Stress ◽  
Gas Analysis ◽  
Deionized Water ◽  
Controlled Environment ◽  
Gas Analyzer ◽  
Leaf Ontogeny ◽  
Infrared Gas Analyzer

A rapid method of determining CO2 compensation concentrations was developed and applied to woody plants. Whole leaves, needle fascicles, and twigs were excised, the cut ends inserted in a vial of deionized water, and the assembly placed in a Mylar bag. The bag was filled with air containing ca. 400 p.p.m. CO2. After 1 h in a growth chamber (24 °C, 3800 ft-c (40 660 lux)), the air was expelled from the bag through an infrared gas analyzer. Compensation concentrations determined by this method agreed with values obtained by using conventional closed-circuit gas analysis. The method was successfully applied to 14 gymnosperm and 55 angiosperm woody species and clones, including field-grown plants and rooted cuttings grown under controlled environment. Variation among species was small, compensation concentrations usually falling between 55 and 65 p.p.m. CO2, the range associated with C3 plants. The influence of temperature, moisture stress, and leaf ontogeny on leaf CO2 compensation also was studied.

Nondispersive Infrared Gas Analyzer for Vapor Density Measurements of a Carbonyl-Containing Organometallic Cobalt Precursor

2017 ◽  
Vol 71 (12) ◽  
pp. 2632-2642 ◽  
Author(s):  
James E. Maslar ◽  
William A. Kimes ◽  
Brent A. Sperling ◽  
Ravindra K. Kanjolia
Keyword(s):  
Bandpass Filter ◽  
Sampling Rate ◽  
Signal Averaging ◽  
Gas Analyzer ◽  
Vapor Density ◽  
Flow Conditions ◽  
Ft Ir ◽  
Infrared Gas Analyzer ◽  
Ft Ir Spectroscopy

A nondispersive infrared (NDIR) gas analyzer was demonstrated for measuring the vapor-phase density of the carbonyl-containing organometallic cobalt precurso μ2-η2-(tBu-acetylene) dicobalthexacarbonyl (CCTBA). This sensor was based on direct absorption by CCTBA vapor in the C≡O stretching spectral region and utilized a stable, broadband IR filament source, an optical chopper to modulate the source, a bandpass filter for wavelength isolation, and an InSb detector. The optical system was calibrated by selecting a calibration factor to convert CCTBA absorbance to a partial pressure that, when used to calculate CCTBA flow rate and CCTBA mass removed from the ampoule, resulted in an optically determined mass that was nominally equal to a gravimetrically-determined mass. In situ Fourier transform infrared (FT-IR) spectroscopy was performed simultaneously with the NDIR gas analyzer measurements under selected conditions in order to characterize potential spectroscopic interferences. Interference due to CO evolution from CCTBA was found to be small under the flow conditions employed here. A CCTBA minimum detectable molecular density as low as ≈3 × 1013 cm−3 was calculated (with no signal averaging and for a sampling rate of 200 Hz). While this NDIR gas analyzer was specifically tested for CCTBA, it is suitable for characterizing the vapor delivery of a range of carbonyl-containing precursors.

TROCAS GASOSAS EM PLANTAS DE CANA-DE-AÇÚCAR INOCULADAS COM GLUCONACETOBACTER DIAZOTROPHICUS E SUBMETIDAS AOS ESTRESSES SALINO E HÍDRICO

2020 ◽  
Vol 03 (01) ◽  
pp. 57-63
Author(s):  
Janice Dias ◽  
Keyword(s):  
Abiotic Stress ◽  
Stomatal Conductance ◽  
Gas Exchange ◽  
Endophytic Bacteria ◽  
Gluconacetobacter Diazotrophicus ◽  
Gas Analyzer ◽  
Sugarcane Crop ◽  
Lower Productivity ◽  
High Doses ◽  
Infrared Gas Analyzer

The sugarcane crop isconsidered moderately sensitive to environmental stresses, which results in reduced growth and lower productivity. In addition, there is a need for the application of high doses of nitrogen fertilizer. A potential and agroecologically correct alternative is the use of nitrogen-fixing endophytic bacteria, such as Gluconacetobacter diazotrophicus. However, under conditions of abiotic stress the benefits from this plant-endophyte association can be altered due to the physiology of stress response. The objective of this work was to study the effect of inoculation of G. diazotrophicus by means of the evaluation of the parameters of gas exchange, in sugarcane plants submitted to salt and water stresses. The rates of stomatal conductance, transpiration and liquid photosynthesis were evaluated by means of a portable infrared gas analyzer (IRGA). The results showed that the presence of the bacteria may alter the rates of stomatal conductance and transpiration, interfering in the physiology of response to salinity and drought. Keywords: Endophytic bactéria. Stomatal conductance. Transpiration. Salinity. Drought.

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