Range-resolved detection of potassium chloride using picosecond differential absorption light detection and ranging

Leffler, Tomas; Brackmann, Christian; Ehn, Andreas; Kaldvee, Billy; Aldén, Marcus; Berg, Mats; Bood, Joakim

doi:10.1364/ao.54.001058

Cited by 12 publications

(7 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…(Thorlabs). The collimated UV light beam subsequently passed through another aperture (4) and through the quartz windows on each side of the calibration cell (5), which in turn was located in the furnace (6). The transmitted light was collected in an UV-enhanced aluminium reflective collimator (7) with a diameter of 12 mm and an SMA connector for an optical fibre (Thorlabs).…”

Section: The Absorption Spectroscopy Setupmentioning

confidence: 99%

“…While quantitative species concentrations in principle can be achieved by evaluation of measurements using the literature data for necessary physical quantities, e.g., absorption cross sections, for many cases, calibration under well-defined experimental conditions is necessary. For example, there might be insufficient data for relevant species such as an absorption cross section for potassium hydroxide as reported by Sorvajärvi et al 5 New techniques developed for flue gas measurements, such as the LIDAR concept for KCl detection, 6 also require calibration for a) Electronic mail: tomas.leffler@forbrf.lth.se accurate quantitative measurements. Moreover, extension of instruments based on broadband absorption such as the in situ alkali chloride monitor (IACM) 7,8 to incorporate additional alkali species also call for the possibility to measure well-defined reference spectra.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Development of an alkali chloride vapour-generating apparatus for calibration of ultraviolet absorption measurements

Leffler

Brackmann

Berg

et al. 2017

Review of Scientific Instruments

View full text Add to dashboard Cite

A novel design of alkali chloride vapour-generating cell has been developed, which can serve as a calibration cell for quantitative ultraviolet absorption concentration measurements and meticulous spectral investigations of alkali compounds. The calibration cell was designed to provide alkali vapour of well-controlled concentrations and temperatures, and consisted of a sealed quartz cell measuring 0.4 m in length with a temperature-controlled reservoir containing solid alkali salt. The cell was placed in a furnace and the alkali vapours generated from the reservoir have direct access to the measuring chamber. Investigations of potassium chloride (KCl) were made on sublimated vapour at temperatures 650, 700, 750, 780, and 800 °C while the reservoir temperature was kept 50 °C lower to avoid condensation. The cell provides stable KCl vapour pressures, and the furnace provides a homogenous temperature profile along the cell. KCl vapour pressures are well characterised and conform the base for determination of the KCl concentration in the cell. The alkali chloride levels matched the concentration range of the absorption setup and indicated a previously employed calibration method to overestimate KCl concentrations. The KCl absorption cross sections for wavelengths λ=197.6 nm and λ=246.2 nm were calculated to be 3.4 × 10−17 and 2.9 × 10−17 cm2/molecule, respectively. The absorption cross section spectra did not show any structural differences with increasing temperature, which could indicate influence of dimers or significant changes of the population in the KCl vibrational states. The KCl absorption cross sections thus did not show any temperature dependence in the temperature region of 700–800 °C. Moreover, the applicability of the calibration cell for measurement of other alkali chlorides and hydroxides is discussed.

show abstract

Section: The Absorption Spectroscopy Setupmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Development of an alkali chloride vapour-generating apparatus for calibration of ultraviolet absorption measurements

Leffler

Brackmann

Berg

et al. 2017

Review of Scientific Instruments

View full text Add to dashboard Cite

show abstract

“…21 This data is also required for other online measurements techniques, such as laser-induced photofragmentation spectroscopy and differential absorption light detection and ranging (LIDAR). 22,23 Previous works have been targeted on the measurements of UV absorption cross-section of alkali chlorides. Davidovits and Brodhead measured the UV absorption cross-section for gas-phase alkali halides in the wavelength range between 200 nm and 400 nm.…”

Section: Introductionmentioning

confidence: 99%

Spectrally Resolved Ultraviolet (UV) Absorption Cross-Sections of Alkali Hydroxides and Chlorides Measured in Hot Flue Gases

et al. 2018

Self Cite

View full text Add to dashboard Cite

Spectrally resolved ultraviolet (UV) absorption cross-sections of gas-phase sodium chloride (NaCl), potassium hydroxide (KOH), and sodium hydroxide (NaOH) were measured, for the first time, in hot flue gases at different temperatures. Homogenous gas-phase NaCl, KCl (potassium chloride), NaOH, and KOH at temperatures 1200 K, 1400 K, 1600 K, and 1850 K were prepared in the post-flame zone of laminar flames by seeding nebulized droplets out of aqueous solution of corresponding alkali species. The amount of droplets seeded into the flame was kept constant, so the relative concentration of different alkali species can be derived. The broadband UV absorption cross-section of KCl vapor reported by Leffler et al. was adopted to derive the absorption cross-section curves of NaCl, NaOH, and KOH with the corresponding measured spectrally resolved absorbance spectra. No significant changes in the spectral structures in the absorption cross-sections were found as the temperature varied between 1200 K and 1850 K, except for NaOH at around 320 nm. The difference between the absorption spectral curves of alkali chlorides and hydroxides is significant at wavelengths above 300 nm, which thus can be used to distinguish and obtain the concentrations of alkali chlorides and hydroxides in the broadband UV absorption measurements.

show abstract

“…In addition, LiDAR techniques have also been demonstrated for combustion diagnostics recently. A centimeter-scale range resolution for a collection distance of 2.5 m and a detection limit of 30 ppm for measurement of potassium chloride (KCl) in a large-scale boiler were achieved by a picosecond DIAL [84]. A portable Scheimpflug LiDAR system was developed and used for large-scale (~1-20 m) combustion diagnostics [85].…”

Section: Differential Absorption Lidar (Dial)mentioning

confidence: 99%

Standoff Chemical Detection Using Laser Absorption Spectroscopy: A Review

et al. 2020

Remote Sensing

View full text Add to dashboard Cite

Remote chemical detection in the atmosphere or some specific space has always been of great interest in many applications for environmental protection and safety. Laser absorption spectroscopy (LAS) is a highly desirable technology, benefiting from high measurement sensitivity, improved spectral selectivity or resolution, fast response and capability of good spatial resolution, multi-species and standoff detection with a non-cooperative target. Numerous LAS-based standoff detection techniques have seen rapid development recently and are reviewed herein, including differential absorption LiDAR, tunable laser absorption spectroscopy, laser photoacoustic spectroscopy, dual comb spectroscopy, laser heterodyne radiometry and active coherent laser absorption spectroscopy. An update of the current status of these various methods is presented, covering their principles, system compositions, features, developments and applications for standoff chemical detection over the last decade. In addition, a performance comparison together with the challenges and opportunities analysis is presented that describes the broad LAS-based techniques within the framework of remote sensing research and their directions of development for meeting potential practical use.

show abstract

Range-resolved detection of potassium chloride using picosecond differential absorption light detection and ranging

Cited by 12 publications

References 15 publications

Development of an alkali chloride vapour-generating apparatus for calibration of ultraviolet absorption measurements

Development of an alkali chloride vapour-generating apparatus for calibration of ultraviolet absorption measurements

Spectrally Resolved Ultraviolet (UV) Absorption Cross-Sections of Alkali Hydroxides and Chlorides Measured in Hot Flue Gases

Standoff Chemical Detection Using Laser Absorption Spectroscopy: A Review

Contact Info

Product

Resources

About