@misc{RueckBierlLechneretal., author = {R{\"u}ck, Thomas and Bierl, Rudolf and Lechner, Alfred and Graf, Antonia and Dams, Florian and Schreiner, Rupert and Auchter, Eberhard and Kriz, Willy and Deubzer, MIchael and Schiller, Frank and Mottok, J{\"u}rgen and Niemetz, Michael and Margull, Ulrich and Hagel, Georg and Utesch, Matthias and Waldherr, Franz and B{\"o}hm, Matthias and Fraunhoffer, Judith and Gardeia, Armin and Schneider, Ralph and Streubel, Janet and Landes, Dieter and Studt, Reimer and Peuker, Dominik and Scharfenberg, Georg and Hook, Christian and Schuster, Dietwald and Ehrlich, Ingo and Dinnebier, Heinrich and Briem, Ulrich and L{\"a}mmlein, Stephan and Koder, Alexander and Bialek, Adam and Genewsky, Axel and Neumeier, Michael and Schlosser, Philipp and Rabl, Hans-Peter and Paule, Matthias and Galster, Christoph and Schiedermeier, Michael and Zwickel, Andreas and Hobmeier, Christoph and Bischoff, Tobias and Rill, Georg and Schaeffer, Thomas and Arbesmeier, Martin and Groß, Andreas and Schlegl, Thomas and Becker, Mark and Senn, Konrad and Schliekmann, Claus and Scholz, Peter and Sippl, Christian and Grill, Martin}, title = {Forschungsbericht 2011 / Hochschule f{\"u}r Angewandte Wissenschaften - Fachhochschule Regensburg}, editor = {Eckstein, Josef}, address = {Regensburg}, organization = {Hochschule f{\"u}r Angewandte Wissenschaften Regensburg}, issn = {1868-3533}, doi = {10.35096/othr/pub-732}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-7321}, language = {de} } @article{PangerlMuellerRuecketal., author = {Pangerl, Jonas and M{\"u}ller, Max and R{\"u}ck, Thomas and Weigl, Stefan and Bierl, Rudolf}, title = {Characterizing a sensitive compact mid-infrared photoacoustic sensor for methane, ethane and acetylene detection considering changing ambient parameters and bulk composition (N2, O2 and H2O)}, series = {Sensors and Actuators B: Chemical}, volume = {352,1}, journal = {Sensors and Actuators B: Chemical}, publisher = {Elsevier}, doi = {10.1016/j.snb.2021.130962}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-25868}, pages = {1 -- 12}, abstract = {We present a sensitive and compact interband cascade laser (ICL) based photoacoustic setup for the detection of gaseous hydrocarbons and discuss its applicability towards trace gas analysis. We investigated the performance of the sensor for trace concentrations of methane, ethane and acetylene diluted in nitrogen. The excitation of methane and ethane was accomplished using one tunable diode laser, covering a range from 3360 to 3372 nm, which was replaced by a separate ICL at 3025 nm for acetylene detection. The influence of ambient parameters such as temperature, flow rate and pressure as well as potential cross-sensitivities towards O2 and H2O have been examined in terms of methane and acetylene detection. A series of simulations proved several of these influences to be attributed to relaxation effects. With a 3σ limit of detection (LoD) of 6.8 parts per billion (ppbV) in case of methane, 2.3 ppbV regarding ethane and 3.6 ppbV in terms of acetylene, the sensor demonstrates a great potential for applications in the field of trace gas analysis.}, language = {en} } @article{MuellerRueckJobstetal., author = {M{\"u}ller, Max and R{\"u}ck, Thomas and Jobst, Simon and Pangerl, Jonas and Weigl, Stefan and Bierl, Rudolf and Matysik, Frank-Michael}, title = {An Algorithmic Approach to Compute the Effect of Non-Radiative Relaxation Processes in Photoacoustic Spectroscopy}, series = {Photoacoustics}, volume = {26}, journal = {Photoacoustics}, publisher = {Elsevier}, doi = {10.1016/j.pacs.2022.100371}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-39935}, abstract = {Successful transfer of photoacoustic gas sensors from laboratory to real-life applications requires knowledge about potential cross-sensitivities towards environmental and gas matrix changes. Multi-dimensional calibration in case of cross-sensitivities can become very complex or even unfeasible. To address this challenge, we present a novel algorithm to compute the collision based non-radiative efficiency and phase lag of energy relaxation on a molecular level (CoNRad) for photoacoustic signal calculation. This algorithmic approach allows to calculate the entire elaxation cascade of arbitrarily complex systems, yielding a theoretical photoacoustic signal. In this work the influence of varying bulk compositions, i.e. nitrogen (N2), oxygen (O2) and water (H2O) on the photoacoustic signal during methane (CH4) detection is demonstrated. The applicability of the algorithm to other photoacoustic setups is shown exemplary by applying it to the relaxational system investigated in [1]. Hayden et al. examined the effect of water on photoacoustic carbon monoxide (CO) detection.}, language = {en} } @misc{RueckHofmannBierl, author = {R{\"u}ck, Thomas and Hofmann, Matthias and Bierl, Rudolf}, title = {Development of a miniaturized photoacoustic multigas sensing system for trace gas measurement}, series = {17th International Conference on Photoacoustic and Photothermal Phenomena, Oct. 20-24, 2013, Suzhou China}, journal = {17th International Conference on Photoacoustic and Photothermal Phenomena, Oct. 20-24, 2013, Suzhou China}, language = {en} } @misc{RueckMatysikBierl, author = {R{\"u}ck, Thomas and Matysik, Frank-Michael and Bierl, Rudolf}, title = {Development of a miniaturized photoacoustic multigas sensing system for trace gas measurement}, series = {analytica conference 2014, 1. bis 4. April, M{\"u}nchen}, journal = {analytica conference 2014, 1. bis 4. April, M{\"u}nchen}, language = {en} } @misc{RueckMatysikBierl, author = {R{\"u}ck, Thomas and Matysik, Frank-Michael and Bierl, Rudolf}, title = {Comparison of acoustic detectors for use in miniaturized photoacoustic devices designed for nitrogen dioxide trace gas measurement}, series = {ANAKON, 23.-26.3.2015, Graz}, journal = {ANAKON, 23.-26.3.2015, Graz}, language = {en} } @article{PangerlSukulRuecketal., author = {Pangerl, Jonas and Sukul, Pritam and R{\"u}ck, Thomas and Fuchs, Patricia and Weigl, Stefan and Miekisch, Wolfram and Bierl, Rudolf and Matysik, Frank-Michael}, title = {An inexpensive UV-LED photoacoustic based real-time sensor-system detecting exhaled trace-acetone}, series = {Photoacoustics}, volume = {38}, journal = {Photoacoustics}, publisher = {Elsevier}, issn = {2213-5979}, doi = {10.1016/j.pacs.2024.100604}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-71279}, pages = {12}, abstract = {n this research we present a low-cost system for breath acetone analysis based on UV-LED photoacoustic spectroscopy. We considered the end-tidal phase of exhalation, which represents the systemic concentrations of volatile organic compounds (VOCs) - providing clinically relevant information about the human health. This is achieved via the development of a CO2-triggered breath sampling system, which collected alveolar breath over several minutes in sterile and inert containers. A real-time mass spectrometer is coupled to serve as a reference device for calibration measurements and subsequent breath analysis. The new sensor system provided a 3σ detection limit of 8.3 ppbV and an NNEA of 1.4E-9 Wcm 1Hz 0.5. In terms of the performed breath analysis measurements, 12 out of 13 fell within the error margin of the photoacoustic measurement system, demonstrating the reliability of the measurements in the field.}, language = {en} } @article{EscherRueckJobstetal., author = {Escher, Lukas and R{\"u}ck, Thomas and Jobst, Simon and Pangerl, Jonas and Bierl, Rudolf and Matysik, Frank-Michael}, title = {Photodissociation-Driven Photoacoustic Spectroscopy with UV-LEDs for Ozone Detection}, series = {Photoacoustics}, volume = {43}, journal = {Photoacoustics}, publisher = {Elsevier BV}, issn = {2213-5979}, doi = {10.1016/j.pacs.2025.100718}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-80076}, pages = {16}, abstract = {This study presents the development and evaluation of a UV-LED based photoacoustic (PA) measurement system for ozone (O3) detection to demonstrate its potential for low-cost and accurate sensing while for the first time addressing the importance of photodissociation for PA signal generation for O3 in the UV range. With a detection limit of 7.9 ppbV, the system exhibits a significant advancement over state-of-the-art UV-PA O3 detection and is on par with laser-based setups. Following a novel discussion of the PA signal arising from photodissociation and its products, cross-sensitivity effects due to environmental factors such as temperature and gas composition were systematically analyzed. A digital twin driven compensation for these influences was implemented and evaluated. Despite the challenges associated with modeling the effects of H2O and CO2, the PA system shows considerable potential, though further studies in real world applications must be conducted.}, language = {en} } @article{WeiglWittmannRuecketal., author = {Weigl, Stefan and Wittmann, Elisabeth and R{\"u}ck, Thomas and Bierl, Rudolf and Matysik, Frank-Michael}, title = {Effects of ambient parameters and cross-sensitivities from O2, CO2 and H2O on the photoacoustic detection of acetone in the UV region}, series = {Sensors Actuators B Chemical}, journal = {Sensors Actuators B Chemical}, number = {328}, publisher = {Elsevier}, issn = {0925-4005}, doi = {10.1016/j.snb.2020.129001}, abstract = {We present a sensitive UV LED photoacoustic setup for the detection of gaseous acetone and discuss its applicability towards breath analysis. We investigated the performance of the sensor for low acetone concentrations down to 0.1 parts per million (ppmV). The influences of temperature, flow, pressure, optical power and LED duty cycle on the measured signal have been examined. To gain a better understanding of the different effects on the photoacoustic signal, correlation analysis was applied and feature importance was determined using a large measured dataset. Furthermore, the cross-sensitivities towards O2, CO2 and H2O have been studied extensively. Finally, the sensor's performance to detect acetone between 0.1-1 ppmV within gas mixtures simulating breath exhale conditions has been investigated, too. With a limit of detection (LoD) of 12.5 parts per billion (ppbV) (3σ) measured under typical breath exhale gas mixture conditions, the sensor demonstrated a high potential for the application of acetone detection in human breath analysis.}, language = {en} } @unpublished{PangerlSukulRuecketal., author = {Pangerl, Jonas and Sukul, Pritam and R{\"u}ck, Thomas and Fuchs, Patricia and Weigl, Stefan and Miekisch, Wolfram and Bierl, Rudolf and Matysik, Frank-Michael}, title = {An Inexpensive Uv-Led Photoacoustic Based Real-Time Sensor-System Detecting Exhaled Trace-Acetone}, publisher = {Elsevier}, doi = {10.2139/ssrn.4724198}, abstract = {In this research we present a low-cost system for breath acetone analysis based on UV-LED photoacoustic spectroscopy. We considered the end-tidal phase of exhalation, which represents the systemic concentrations of volatile organic compounds (VOCs) - providing clinically relevant information about the human health. This is achieved via the development of a CO2-triggered breath sampling system, which collected alveolar breath over several minutes in sterile and inert containers. A real-time mass spectrometer is coupled to serve as a reference device for calibration measurements and subsequent breath analysis. The new sensor system provided a 3σ detection limit of 6.4 ppbV and an NNEA of 1.1E-9 Wcm-1Hz-0.5. In terms of the performed breath analysis measurements, 12 out of 13 fell within the error margin of the photoacoustic measurement system, demonstrating the reliability of the measurements in the field.}, language = {en} } @article{RueckBierlMatysik, author = {R{\"u}ck, Thomas and Bierl, Rudolf and Matysik, Frank-Michael}, title = {NO2 trace gas monitoring in air using off-beam quartz enhanced photoacoustic spectroscopy (QEPAS) and interference studies towards CO2, H2O and acoustic noise}, series = {Sensors and Actuators B: Chemical}, volume = {255}, journal = {Sensors and Actuators B: Chemical}, number = {Part 3, February}, publisher = {Elsevier}, doi = {10.1016/j.snb.2017.09.039}, pages = {2462 -- 2471}, abstract = {We present the development and characterization as well as comprehensive interference studies of a photoacoustic NO2 trace gas detection system. The system is based on an off-beam quartz enhanced photoacoustic scheme (off-beam QEPAS) and signal generation was initiated by amplitude modulating a low-cost diode laser emitting at 450 nm. The QEPAS sensor element features double-resonant amplification, still it is only ∼ 5 × 5 × 2.5 mm in size. The individual and combined resonance characteristics were investigated and specified to 52 dB amplification, adding up 15 dB acoustic- and 37 dB mechanical-resonance amplification. The linearity of the photoacoustic signal dependency on the analyte concentration was verified from 200 ppbV to 100 ppmV NO2 in synthetic air. The detection limit (3σ) was determined to 1.8 ppbV using a lock-in time constant of 10 s and an averaging time of 20 s. The normalized noise equivalent absorption coefficient was specified to 2.5·10-8 W cm-1 Hz-0.5. The stability of the signal was investigated over time and a slight drift by 1 per mille was observed after 30 min without temperature stabilizing the photoacoustic cell (PAC). Noise analysis was performed by means of Allan deviation and the inverse dependency of response time and precision of the system on the lock-in time constant was outlined. We performed interference analyses towards N2, O2, CO2, H2O and acoustic noise, respectively. Although neither spectral interferences nor losses due to slow NO2 VT-relaxation were observed, O2 was identified to cause a 15\% signal drop due to VVNO2-O2-relaxation. Changing H2O concentrations were found to cause acoustic detuning, which cannot be compensated by adjusting the frequency of modulation, because of the double-resonant feature of the PAC. However, alternative approaches of compensation were discussed. Finally, we carried out heavy traffic noise simulations and determined the QEPAS setup to be 46 times less susceptible towards ambient noise compared to standard microphone-based photoacoustic setups.}, language = {en} } @article{RueckBierlMatysik, author = {R{\"u}ck, Thomas and Bierl, Rudolf and Matysik, Frank-Michael}, title = {Development and characterization of a laboratory setup for photoacoustic NO2 determination based on the excitation of electronic 2B2 and 2B1 states using a low-cost semiconductor laser}, series = {Sensors and Actuators A: Physical}, volume = {258}, journal = {Sensors and Actuators A: Physical}, publisher = {Elsevier}, address = {Amsterdam, Niederlande}, doi = {10.1016/j.sna.2017.03.024}, pages = {193 -- 200}, abstract = {This work gives a detailed characterization of a laboratory setup for photoacoustic NO2 trace gas detection at the ppb level. The signal generation is based on the excitation of electronic 2B2 and 2B1 states using a low-cost semiconductor laser emitting at 450 nm. An acoustic resonator was used for signal amplification and the modulation frequency of the laser was determined to 3395 Hz in order to gain maximum signal amplification. The quality of resonant amplification was determined to 7.9. The gas samples were NO2 calibration gases diluted with pure nitrogen. The signal-to-noise ratio (SNR) dependency on the flow rate Q and the lock-in time constant τLIA was investigated, respectively, and the optimum values were specified to Q = 500 mL/min and τLIA = 2 s. In case of ambient noise, increasing τLIA to 10 s was evaluated as sufficient for SNR preservation. The noise level was measured in the absence of NO2 and it was determined to be composed of 51\% electronic noise and 49\% gas flow noise. With the analyte concentration ranging from 300 ppbV to 100 ppmV, the linear dependency of the photoacoustic amplitude on the NO2 concentration was specified, the sensitivity was determined to 110 μV/ppmV and the maximum measurement error was calculated to ±0.8\%. The detection limit was determined to 2.0 ppbV. Furthermore, the stability of the signal was investigated and a maximum drift of ±1\% was observed within a measuring period of 30 min. The response time τ90 was specified to 58 s. All results considered, this photoacoustic measuring system, which is based on low-cost signal generation and detection units, provides an excellent basis in view of developing a portable device for photoacoustic trace gas detection.}, language = {en} } @article{RueckBierlMatysik, author = {R{\"u}ck, Thomas and Bierl, Rudolf and Matysik, Frank-Michael}, title = {Low-cost photoacoustic NO2 trace gas monitoring at the pptV-level}, series = {Sensors and Actuators A: Physical}, volume = {263}, journal = {Sensors and Actuators A: Physical}, publisher = {Elsevier}, address = {Amsterdam, Niederlande}, doi = {10.1016/j.sna.2017.06.036}, pages = {501 -- 509}, abstract = {We present the development and the characterization of a photoacoustic NO2 trace gas detection system. The system is based on the implementation of low-cost components, i.e. a mass-produced blue diode laser and a standard MEMS microphone which is commonly built into smartphones, for example. An optimized cell design was realized by means of 3D printing. The linearity of the photoacoustic signal dependency on the analyte concentration was verified from 200 ppbV to 100 ppmV NO2. The detection limit (1σ) was determined to 33 pptV and the normalized noise equivalent absorption coefficient was calculated to 7.0 ∙ 10-10 W cm-1 Hz-1/2. The dynamic range of the system was verified to be linear over three magnitudes of order and the sensitivity was calculated to 814 μV/ppmV. The system was characterized in view of optimal operating parameters, i.e. lock-in time constant τLIA and total mass flow rate, optical performance and signal stability. The mass flow dependend response time of the system was specified to 19 s and an idealized step response to a quasi-Heaviside step function was quantified as a function of τLIA. The quality factor of acoustic resonance was determined to 21.9 and an empirical expression regarding acoustic node shifting is provided. The expression takes into account the radius of the resonator pipe and the radius of the hole, which was drilled into the pipe for microphone coupling. Furthermore, we studied the cross-sensitivity of the photoacoustic signal towards H2O and CO2, respectively.}, language = {en} } @inproceedings{ZhouLandgrafRuecketal., author = {Zhou, Qi and Landgraf, Ferdinand and R{\"u}ck, Thomas and Bierl, Rudolf}, title = {Resonance frequency tuning and process design of a micromechanical capacitive cantilever in a photoacoustic trace-gas sensing device}, series = {7. MikroSystemTechnik Kongress "MEMS, Mikroelektronik, Systeme", 23.-25. Oktober 2017, M{\"u}nchen}, booktitle = {7. MikroSystemTechnik Kongress "MEMS, Mikroelektronik, Systeme", 23.-25. Oktober 2017, M{\"u}nchen}, publisher = {VDE-Verlag}, address = {Berlin}, isbn = {978-3-8007-4491-6}, abstract = {Photoacoustic spectroscopy is an efficient method to detect the concentration of trace gases with following advantages: short response time, high sensitivity, continuous and real-time monitoring and the option of miniaturization without the need of complex mirror-based multi-pass cell designs. A micromechanical cantilever is used as a key component in a two-part "Cantilever-Resonator" system that detects the weak photoacoustic signal. The resonance frequency of cantilever needs to be tuned to match the resonance frequency of resonator in order to achieve the maximum vibration amplitude of the "Cantilever-Resonator" system. This paper reports a post-fabrication method to tune the resonance frequency of cantilevers via focused ion beam (FIB) and a capacitive solution for the cantilever to transform the acoustic signal to electrical signal.}, language = {en} } @inproceedings{RueckLaeppleBierl, author = {R{\"u}ck, Thomas and L{\"a}pple, I. and Bierl, Rudolf}, title = {Photoakustische Spurengasanalytik von NO2 im ppt-Bereich (10^-12) bei Verwendung kosteng{\"u}nstiger Einzelkomponenten}, series = {7. MikroSystemTechnik Kongress "MEMS, Mikroelektronik, Systeme", 23.-25. Oktober 2017, M{\"u}nchen}, booktitle = {7. MikroSystemTechnik Kongress "MEMS, Mikroelektronik, Systeme", 23.-25. Oktober 2017, M{\"u}nchen}, publisher = {VDE-Verlag}, address = {Berlin}, isbn = {978-3-8007-4491-6}, language = {de} } @article{ZaglerLandgrafRuecketal., author = {Zagler, Andreas and Landgraf, Ferdinand and R{\"u}ck, Thomas and Bierl, Rudolf}, title = {Entwicklung eines mikromechanischen kapazitiven Schalldetektors im resonanten Betrieb f{\"u}r die photoakustische Spurengasanalyse}, series = {7. MikroSystemTechnik Kongress "MEMS, Mikroelektronik, Systeme", 23.-25. Oktober 2017, M{\"u}nchen}, journal = {7. MikroSystemTechnik Kongress "MEMS, Mikroelektronik, Systeme", 23.-25. Oktober 2017, M{\"u}nchen}, publisher = {VDE-Verlag}, address = {Berlin}, language = {de} } @inproceedings{GaidaWeiglRuecketal., author = {Gaida, Peter and Weigl, Stefan and R{\"u}ck, Thomas and Bierl, Rudolf}, title = {Portable photoakustische Messeinheit zur NO2 Detektion im Spurenbereich}, series = {7. MikroSystemTechnik Kongress "MEMS, Mikroelektronik, Systeme", 23.-25. Oktober 2017, M{\"u}nchen}, booktitle = {7. MikroSystemTechnik Kongress "MEMS, Mikroelektronik, Systeme", 23.-25. Oktober 2017, M{\"u}nchen}, publisher = {VDE-Verlag}, address = {Berlin}, isbn = {978-3-8007-4491-6}, language = {de} } @inproceedings{WeiglGaidaRuecketal., author = {Weigl, Stefan and Gaida, Peter and R{\"u}ck, Thomas and Bierl, Rudolf}, title = {Portable Measurement Unit for NO2 Trace Gas Detection}, series = {PHOTOPTICS 2018, 6th International Conference on Photonics, Optics and Laser Technology, 25 - 27 January 2018, Funchal Madeira}, booktitle = {PHOTOPTICS 2018, 6th International Conference on Photonics, Optics and Laser Technology, 25 - 27 January 2018, Funchal Madeira}, language = {en} } @techreport{UngerRueckLandgrafetal., author = {Unger, J. and R{\"u}ck, Thomas and Landgraf, Ferdinand and Bierl, Rudolf}, title = {Herstellung und Analyse der Resonanzfrequenz eines MEMS Cantilever f{\"u}r das CEPAS Verfahren}, abstract = {Diese Abhandlung beschreibt das Konzept eines mikroeletromechanischen Systems (MEMS), das im Messverfahren der cantilever enhanced photoacoustic spectroscopy (CEPAS) Verwendung finden soll. Es wird die Herstellung eines einseitig eingespannten Biegebalkens aus Silizium mittels deep reactiv ion etching (DRIE) beschrieben. Des Weiteren wird die Resonanzfrequenz dieses Cantilevers mit Hilfe Laservibrometertechnik untersucht. Die resultierenden resonanten Schwingungen 0.Ordnung werden mit den Ergebnissen einer vereinfachten theoretischen N{\"a}herung verglichen. Die Messergebnisse stehen in gutem Zusammenhang mit den theoretischen Werten. Solche Cantilever, die aus silicon on insula tor (SOI) Wafer angefertigt wurden, weisen bei einer Zielfrequenz ein mittlere Abweichung von Δf = 118±26Hz (bzw.Δf =0,76±0,17\%) auf.}, language = {de} } @inproceedings{HofmannBierlRueck, author = {Hofmann, Matthias and Bierl, Rudolf and R{\"u}ck, Thomas}, title = {Implementation of a dual-phase lock-in amplifier on a TMS320C5515 digital signal processor}, series = {Proceedings of the 5th European DSP Education and Research Conference (EDERC), 13-14 Sept. 2012, Amsterdam}, booktitle = {Proceedings of the 5th European DSP Education and Research Conference (EDERC), 13-14 Sept. 2012, Amsterdam}, doi = {10.1109/EDERC.2012.6532217}, abstract = {A digital dual-phase lock-in amplifier that is capable to run on a low-cost, low-power platform comprising a 16-bit fixed-point digital signal processor was developed. This is achieved by a set of optimised digital filters including an exponential averager to adjust the time constant of the overall filter. The reference frequency is generated using a direct digital synthesis source utilising angle decomposition with a resolution of 1 Hz. The digital lock-in algorithm is described and the performance of the algorithm is analysed. The experimental results show that the developed lock-in amplifier achieves similar performance to a commercially available lock-in amplifier.}, language = {en} } @inproceedings{RueckLandgrafLaeppleetal., author = {R{\"u}ck, Thomas and Landgraf, Ferdinand and L{\"a}pple, I. and Unger, J. and Matysik, Frank-Michael and Bierl, Rudolf}, title = {Specification of an improved photoacoustic setup for high-sensitive, low-cost NO2 trace gas detection}, series = {18th International Conference on Photoacoustic and Photothermal Phenomena (ICPPP18), 2015, September 6-10, Novi Sad, Serbia}, booktitle = {18th International Conference on Photoacoustic and Photothermal Phenomena (ICPPP18), 2015, September 6-10, Novi Sad, Serbia}, language = {en} } @unpublished{RueckMuellerJobstetal., author = {R{\"u}ck, Thomas and M{\"u}ller, Max and Jobst, Simon and Weigl, Stefan and Pangerl, Jonas and Bierl, Rudolf and Matysik, Frank-Michael}, title = {Digital Twin of a Photoacoustic Trace Gas Sensor for Monitoring Methane in Complex Gas Compositions}, publisher = {Elsevier / SSRN}, doi = {10.2139/ssrn.4215170}, pages = {22}, abstract = {The digitalization of industrial processes requires smart sensor systems. Photoacoustic spectroscopy is well suited for this purpose as it allows for small-sized and low-cost trace gas analysis. However, the method is susceptible to changes in measurement conditions and standard calibration routines often fail to correct for all changes. We therefore created a Digital Twin (DT) of a photoacoustic trace gas sensor for methane and evaluated it regarding variations in gas composition (CH4, N2, O2, CO2, H2O), temperature and pressure. With a mean absolute percentage error of 0.8 \% the accuracy of the sensor after DT compensation significantly exceeds the 24 \% achieved based on standard calibration in nitrogen. For the first time, we can fully analytically compute the photoacoustic signal under moderate ambient conditions with an error in the ppbV range by taking a holistic approach. Assuming knowledge of the underlying energy transfer processes, the model of this Digital Twin can be adapted to any microphone based photoacoustic sensor for monitoring any analyte species.}, language = {en} } @inproceedings{MuellerRueckJobstetal., author = {M{\"u}ller, Max and R{\"u}ck, Thomas and Jobst, Simon and Pangerl, Jonas and Bierl, Rudolf and Matysik, Frank-Michael}, title = {Creating a Digital Twin of a Photoacoustic Gas Sensor for Methane Detection in Complex Gas Matrices}, series = {Proceedings Optical Sensors and Sensing Congress 2022 (AIS, LACSEA, Sensors, ES): 11-15 July 2022, Vancouver, British Columbia, Canada}, booktitle = {Proceedings Optical Sensors and Sensing Congress 2022 (AIS, LACSEA, Sensors, ES): 11-15 July 2022, Vancouver, British Columbia, Canada}, publisher = {Optica Publishing Group}, isbn = {978-1-957171-10-4}, doi = {10.1364/LACSEA.2022.LW4D.2}, abstract = {We present the calculation results from a digital twin (DT) of our photoacoustic (PA) sensor for methane detection, regarding gas composition, temperature and pressure variations.}, language = {en} }