Gasera Ltd

Turku, Finland

Gasera Ltd

Turku, Finland
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Hirschmann C.B.,University of Oulu | Hirschmann C.B.,VTT Technical Research Center of Finland | Lehtinen J.,University of Turku | Uotila J.,Gasera Ltd. | And 3 more authors.
Applied Physics B: Lasers and Optics | Year: 2013

A novel cantilever enhanced photoacoustic spectrometer with mid-infrared quantum cascade laser was applied for selective and sensitive formaldehyde (CH2O) gas measurement. The spectrum of formaldehyde was measured from 1,772 to 1,777 cm-1 by tuning the laser with a spectral resolution of 0.018 cm-1. The band at 1,773.959 cm-1 was selected for data analysis, at which position the laser emitted 47 mW. In univariate measurement, the detection limit (3σ, 0.951 s) and the normalized noise equivalent absorption coefficient (3σ) for amplitude modulation (AM) were 1.6 ppbv and 7.32 × 10-10 W cm -1 (Hz)-1/2 and for wavelength modulation (WM) 1.3 ppbv and 6.04 × 10-10 W cm-1 (Hz)-1/2. In multivariate measurement, the detection limit (3σ) can be as low as 901 pptv (1,773.833-1,774.085 cm-1, 15 spectral points each 0.951 s) for AM and 623 pptv (1,773.743-1,774.265 cm-1, 30 spectral points each 0.951 s) for WM. Because measurement time increases in multivariate measurement, its application is justified only when interferents need to be resolved. Potential improvements of the system are discussed. © 2013 Springer-Verlag Berlin Heidelberg.


Uotila J.,Gasera Ltd. | Lehtinen J.,University of Turku | Kuusela T.,University of Turku | Sinisalo S.,Gasera Ltd. | And 3 more authors.
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2012

Chemical control is a crucial element for controlling the manufacturing and distribution of illegal narcotics and synthetic substances. This work is focusing on the vapor phase point detection methodology due to its applicability in customs, airport and harbor check point scenarios where inspection of trucks, cars, containers, as well as people and baggage is required. There are several techniques available that are able to screen and identify specific molecules even at very low concentration at laboratory or in controlled environment. However, a portable system which would be simple to use, sensitive, compact, and capable of providing screening over a large number of compounds and discriminate them with low probability of false alarms with short response time scale is still demanded. Our solution is to combine cantilever enhanced photoacoustic spectroscopy with external cavity quantum cascade laser (EC-QCL), which is capable of measuring infrared gas phase spectra of the analyte substances. High sensitivity in a wide dynamic range is achieved with a silicon MEMS cantilever sensor coupled with an optical readout system and high power laser source, which is operating at the fundamental vibrational absorption wavelengths. High selectivity is achieved by measuring the infrared spectra of the sample gas utilizing widely tunable EC-QCL technology and novel signal processing methods. Measurements with the breadboard demonstrator of the described system and detection limit estimation were performed to a selected drug precursor target molecules. The measurement results indicate low ppb-level gas phase sensitivity to selected drug precursor substances also in the presence of typical interfering molecules. © 2012 SPIE.


Peltola J.,University of Helsinki | Vainio M.,University of Helsinki | Vainio M.,Center for Metrology and Accreditation | Hieta T.,Center for Metrology and Accreditation | And 5 more authors.
Optics Express | Year: 2013

Highly sensitive cantilever-enhanced photoacoustic detection of hydrogen cyanide and methane in the mid-infrared region is demonstrated. A mid-infrared continuous-wave frequency tunable optical parametric oscillator was used as a light source in the experimental setup. Noise equivalent detection limits of 190 ppt (1 s) and 65 ppt (30 s) were achieved for HCN and CH4, respectively. The normalized noise equivalent absorption coefficient is 1.8 × 10-9 W cm-1 Hz-1/2. © 2013 Optical Society of America.


Hirschmann C.B.,University of Oulu | Hirschmann C.B.,VTT Technical Research Center of Finland | Sinisalo S.,Gasera Ltd. | Uotila J.,Gasera Ltd. | And 3 more authors.
Vibrational Spectroscopy | Year: 2013

A compact measurement system based on a novel combination of cantilever enhanced photoacoustic spectroscopy (CEPAS) and optical parametric oscillator (OPO) was applied to the gas phase measurement of benzene, toluene, and o-, m- and p-xylene (BTX) traces. The OPO had a band width (FWHM) of 1.3 nm, was tuned from 3237 to 3296 nm in steps of 0.1 nm and so spectra of BTX at different concentrations were recorded. The power emitted by the OPO increased from 88 mW at 3237 nm to 103 mW at 3296 nm. The univariate detection limits (3σ, 0.951 s) for benzene, toluene, p-, m- and o-xylene at 3288 nm were 12.0, 9.8, 13.2, 10.1 and 16.0 ppb, respectively. Multivariate data analysis using science-based calibration was used to resolve the interference of the analytes. The multivariate detection limits (3σ, 3237-3296 nm, 591 spectral points each 0.951 s) for benzene, toluene, p-, m- and o-xylene in the multi-compound sample, where all other analytes and water interfere were 4.3, 7.4, 11.0, 12.5 and 6.2 ppb, respectively. Without interferents, the multivariate detection limits varied between 0.5 and 0.6 ppb. The sum of the cross-selectivities (3237-3296 nm, 591 spectral points, each 0.951 s) per analyte were below 0.05 ppb/ppb, with an average of 0.038 ppb/ppb. The cross-selectivity of water to the analytes was on average 1.22 × 10-4 ppb/ppb. The OPO is small in size (L × W × H 125 × 70 × 45 mm), commercially available, and easy to operate and integrate to setups. The combination with sensitive CEPAS enables compact measurement systems for industrial as well as environmental trace gas monitoring. © 2013 Elsevier B.V.


Sievila P.,Aalto University | Chekurov N.,Aalto University | Raittila J.,Gasera Ltd. | Tittonen I.,Aalto University
Sensors and Actuators, A: Physical | Year: 2013

Silicon cantilever sensors have been designed, fabricated and tested in acoustic wave detection. The principal application of the components is photoacoustic spectroscopy (PAS) which is a highly sensitive method in solid, liquid and gas analysis. The developed microfabrication process of the sensors is based on silicon-on-insulator (SOI) wafer etching, in which the challenge is to control and minimize the residual stress related curving in thin (5 μm) but large-area (few mm2) components. The sensitivity of the fabricated cantilevers is investigated in photoacoustic measurements of solid samples, and the signal strength is shown to increase tens of percent compared with the results obtained with previously reported cantilever microphones. Improvement of the signal-to-noise ratio (SNR) verifies the advantage of the presented cantilevers in photoacoustic sensing. © 2012 Elsevier B.V.


Patent
Gasera Ltd | Date: 2010-12-08

The present invention relates to an arrangement for measuring relative movement. The measuring arrangement comprises a light source (110, 210) for emitting a light beam, a moving element (120, 220) having a reflective surface (121, 221) adapted to reflect a first wavefront portion of the light beam, and a reference element (130, 230) having a reflective surface (131, 231) adapted to reflect a second wavefront portion of the light beam. The arrangement further comprises detecting means (140, 240) for detecting changes in a spatial interference pattern produced by the light reflected from the moving element and the reference element, and processing means (150, 160, 250, 260) for calculating the relative movement between the moving element and the reference element from the phase change in the detected spatial interference pattern. The invention also relates to a method for measuring relative movement.


The present invention relates to a supporting structure for a movable mirror of an interferometer, the supporting structure comprising a fixed frame (11), a movable frame (12) to which the movable mirror (42) is arranged to be attachable, and at least two flexible members (13), first ends of said members (13) being fastened to the fixed frame (11) and second ends of said members (13) being fastened to the movable frame (12) in such a way that the distance between fixing points of each flexible member (13) is essentially the same and the distance between the fixing points of the first ends essentially equals the distance between the fixing points of the second ends. The supporting structure comprises support members (16) attached to at least one side of at least two flexible members (13). The invention also relates to an interferometer and a method for reducing the tilting of a movable mirror of an interferometer.


The present invention relates to a supporting structure for a movable mirror of an interferometer, the supporting structure comprising a fixed frame (11), a movable frame (12) to which the movable mirror (42) is arranged to be attachable, and at least two flexible members (13), first ends of said members (13) being fastened to the fixed frame (11) and second ends of said members (13) being fastened to the movable frame (12) in such a way that the distance between fixing points of each flexible member (13) is essentially the same and the distance between the fixing points of the first ends essentially equals the distance between the fixing points of the second ends. The supporting structure comprises support members (16) attached to at least one side of at least two flexible members (13). The invention also relates to an interferometer and a method for reducing the tilting of a movable mirror of an interferometer.


Patent
Gasera Ltd | Date: 2010-06-04

The present invention relates to an arrangement for measuring relative movement. The measuring arrangement comprises a light source (110, 210) for emitting a light beam, a moving element (120, 220) having a reflective surface (121, 221) adapted to reflect a first wavefront portion of the light beam, and a reference element (130, 230) having a reflective surface (131, 231) adapted to reflect a second wavefront portion of the light beam. The arrangement further comprises detecting means (140, 240) for detecting changes in a spatial interference pattern produced by the light reflected from the moving element and the reference element, and processing means (150, 160, 250, 260) for calculating the relative movement between the moving element and the reference element from the phase change in the detected spatial interference pattern. The invention also relates to a method for measuring relative movement.


News Article | October 28, 2016
Site: co.newswire.com

GASERA ONE is a portable device for conducting ultra-sensitive, multi-gas analysis. Using its patented, cantilever-enhanced photoacoustic technology, Gasera Ltd. delivers a market-disruptive solution for climate change prevention, border security, and occupational safety improvement.

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