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1

Regulation of N-type In2O3 Content on the Conductivity Typeof Co3O4 Based Acetone Sensor

Fu Lijuan, Fan Shuxing, Wang Zhao, Tang Wei

Materials Science Poland

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2023

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Vol. 41, No. 1

202--213

EN

A double-jet electrospinning method was adopted to fabricate In2O3/Co3O4 nanofibers (NFs). The sensitivity of In2O3/Co3O4NFs and In2O3NFs were compared and analyzed, and the morphology, structure, chemical composition, and gas-sensing properties of the samples were comprehensively characterized. The results show that the introduction of Co3O4can improve the response of In2O3/Co3O4to acetone, to 29.52 (In2O3/Co3O4) and 12.34 (In2O3) to 200 ppm acetone at 2000°C, respectively. In addition, the doping of Co3O4was found to reduce the optimum working temperature of pure In2O3 from 275°C to 200°C. The composite of Co3O4and In2O3not only enhances the sensing performance, but also leads to a conversion of p-n conductivity type. The phenomenon of the p-n transition is relevant to operating temperature and proportion of In2O3and Co3O4. While the enhanced acetone sensing properties of In2O3/Co3O4NFs may be attributed to the p-n hetero-junction between n-type In2O3 and p-type Co3O4 crystalline grains, which promotes the electron migration. The synergistic effects between In2O3and Co3O4and the large specific surface area of NFs additionally contribute to the improvements of acetone sensing performance.

2

Implementation of computer processing of relaxation processes investigation data using extended exponential function

Lozovskyi Andrii, Lyashkov Alexander, Gomilko Igor, Tonkoshkur Alexander

Informatyka, Automatyka, Pomiary w Gospodarce i Ochronie Środowiska

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2023

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T. 13, nr 3

51--55

EN

The object of research is the development of a specialized measuring information system for the study and control of relaxation processesin materials and technical systems.The purpose of the work isthe use of computer technologies to eliminate routine operations associated withthe processing of experimental data, increase the speed, accuracy and information content of the process of studying the control of gas sensors.A variant of using computer data processing to automate the processing and primary analysis of experimental data of scientific research and controlof the physicochemical parameters of gas-sensitive materials is proposed. The developed computer data processing system provides a practical opportunity to use the measurements of the kinetic characteristics of the gas sensitivity of gas sensors for their experimental research and controland, thus, to achieve higher accuracy and information content.The testing of the developed information-measuring system confirmed its operabilityand compliance with the requirements for improving the accuracy and speed of the processing process.

PL

Przedmiotem badań jest opracowanie specjalistycznego systemu informacji pomiarowej do badania i kontroli procesów relaksacyjnychw materiałach i systemach technicznych. Celem pracy jest wykorzystanie technologii komputerowych do wyeliminowania rutynowych operacji związanych z przetwarzaniem danych eksperymentalnych, zwiększenia szybkości, dokładności i zawartości informacyjnej procesu badania kontroli czujników gazu. Zaproponowano wariant wykorzystania komputerowego przetwarzania danych do automatyzacji przetwarzania i podstawowej analizy danych eksperymentalnych badań naukowych i kontroli parametrów fizykochemicznych materiałów wrażliwych na gaz. Opracowany komputerowy system przetwarzania danych zapewnia praktyczną możliwość wykorzystania pomiarów charakterystyk kinetycznych wrażliwości czujników gazu do ich badań eksperymentalnych i kontroli, a tym samym do osiągnięcia wyższej dokładności i zawartości informacyjnej. Testy opracowanego systemu pomiaru informacji potwierdziły jego funkcjonalność i zgodność z wymaganiami dotyczącymi poprawy dokładności i szybkości procesu przetwarzania.

3

Wykorzystanie technologii GLAD do zastosowań w przenośnych analizatorach oddechu

Grochala Dominik, Paleczek Anna, Bronicki Jakub, Marszałek Konstanty, Rydosz Artur

Przegląd Elektrotechniczny

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2022

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R. 98, nr 12

118--120

PL

W pracy przedstawione zostały najważniejsze parametry technologii osadzania pod kątem GLAD (ang. Glancing Angle Deposition) z wykorzystaniem magnetronowego rozpylania jonowego w celu wytwarzania półprzewodnikowych, rezystancyjnych czujników gazów przeznaczonych do zastosowania w układach elektronicznego nosa (ang. e-nose) do analizy wydychanego powietrza.

EN

In this paper, the major parameters of the GLAD (Glancing Angle Deposition) technique with the utilization of the magnetron sputtering technology were presented. The GLAD technology was applied to deposition of resistive, semiconductor type gas sensors that will be applied to electronic nose (e-nose) for exhaled breath analysis in a portable device.

4

Application of a Gas Sensor Array to Effectiveness Monitoring of Air Contaminated with Toluene Vapors Absorption Process

Dobrzyniewski Dominik, Szulczyński Bartosz, Gębicki Jacek

Journal of Ecological Engineering

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2022

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Vol. 23, nr 10

269--282

EN

This article demonstrates the application of a gas sensor array to monitor the effectiveness of the absorption process of air stream purification from odorous compounds (toluene vapors). A self-constructed matrix consisting of five commercially available gas sensors was used. Multiple linear regression (MLR) was selected as the statistical technique used to calibrate the matrice. Gas chromatography coupled with a flame ionization detector (GC-FID) was used as a reference analytical technique, which enabled to obtain reliable quantitative determinations of toluene concentration in the samples. A commercially available absorption liquid dedicated to non-polar compounds was used as an absorbent. The process was carried out in two identical systems: in first, pure toluene was absorbed and in the second, toluene vapor contaminated with acetone. This approach allowed verifying the selectivity of the prepared MLR calibration model for process control in the case of the presence of more or less expected pollutants in the treated gas. The results obtained with the gas sensor array were related to the reference technique and they confirm the usefulness and advisability of using these devices to monitor the absorption processes as a cheaper and more time-efficient alternative to chromatographic methods. The root mean square error (RMSE) in absorptivity determination between the results received with the analytical and sensor techniques was 0.019 and 0.041 when treating pure toluene vapors and its vapors with acetone, respectively. Compared to instrumental techniques, sensor matrices are technologically less complex, useful for laboratory purposes, as well as showing application potential for field studies. However, it is necessary to develop more sensitive and selective chemical gas sensor arrays and better master advanced data processing and identification techniques.

5

Experimental and Numerical Acoustoelectric Investigation of the New SAW Structure with (RR)-P3HT Polymer in DMMP Detection

Hejczyk Tomasz, Wrotniak Jarosław, Magnuski Mirosław, Jakubik Wiesław

Archives of Acoustics

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2021

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Vol. 46, No. 2

313--322

EN

This document presents the results of numerical analyses of the SAW gas sensor in the steady state. The effect of SAW velocity changes depending on how the surface electrical conductivity of the sensing layer is predicted. The conductivity of roughness sensing layer above the piezoelectric waveguide depends on the profile of the diffused gas molecule concentration inside the layer. Numerical results for the gas DMMP (CAS Number 756-79-6) for layer (RR)-P3HT in the steady state are shown. The main aim of the investigations was to study the thin film interaction with target gases in the SAW sensor configuration based on diffusion equation for polymers. Numerical results for profile concentration in steady state are shown. The results of numerical acoustoelectric analysis (NAA) allow to select the sensor design conditions, including the morphology of the sensor layer, its thickness, operating temperature and layer type. The numerical results based on the code written in Python, are described and analyzed. The theoretical results were verified and confirmed experimentally.

6

Limited selectivity of amperometric gas sensors operating in multicomponent gas mixtures and methods of selectivity improvement

Dmitrzak Marta, Jasinski Piotr, Jasinski Grzegorz

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2020

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Vol. 68, nr 6

1275--1282

EN

In recent years, smog and poor air quality have become a growing environmental problem. There is a need to continuously monitor the quality of the air. The lack of selectivity is one of the most important problems limiting the use of gas sensors for this purpose. In this study, the selectivity of six amperometric gas sensors is investigated. First, the sensors were calibrated in order to find a correlation between the concentration level and sensor output. Afterwards, the responses of each sensor to single or multicomponent gas mixtures with concentrations from 50 ppb to 1 ppm were measured. The sensors were studied under controlled conditions, a constant gas flow rate of 100 mL/min and 50 % relative humidity. Single Gas Sensor Response Interpretation, Multiple Linear Regression, and Artificial Neural Network algorithms were used to predict the concentrations of SO2 and NO2. The main goal was to study different interactions between sensors and gases in multicomponent gas mixtures and show that it is insufficient to calibrate sensors in only a single gas.

7

Adsorption and gas sensing properties of CuFe2O4 nanoparticles

Abu Haija Mohammad, Basina Georgia, Banat Fawzi, Ayesh Ahmad I.

Materials Science Poland

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2019

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Vol. 37, No. 2

289--295

EN

Spinel ferrite nanoparticles in the form CuFe2O4 were tested for gas sensing applications. Nanoparticles pressed in a disk form were used to construct conductometric gas sensors. The disk was placed between two electrical electrodes wherein the top electrode had a grid structure. The produced sensors were tested against H2S and H2 gases and they were found to be selective and sensitive to H2S concentration as low as 25 ppm. The composition of the nanoparticles was confirmed by X-ray diffraction and energy dispersive X-ray spectroscopy measurements. The crystal structure was verified by both X-ray diffraction and transmission electron microscope. The observations obtained from the experiments demonstrated the high potential of using CuFe2O4 nanoparticles for H2S sensing applications.

8

Correction of the dynamic errors of a gas sensor based on the dynamic model with averaged parameters

Urzędniczok H.

Measurement Automation Monitoring

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2016

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Vol. 62, No. 7

214--217

EN

The paper presents a numerical method of dynamic error correction applied to a measuring transducer of gas concentration with a typical sensor based on tin dioxide. The work describes research of the dynamic properties of the transducer. Its response time is approximately 8 to 10 minutes, which may be not acceptable in many applications. A parametric model of the transducer dynamics has been developed and an adequate correction algorithm is proposed. The obtained results of the dynamic correction based on the proposed method are compared with those achieved previously by applying a neural network algorithm. Despite the simplicity of the used model, the proposed method allows a significant decrease in the transducer response time.

9

Liquid petroleum gas sensing performance enhanced by CuO modification of nanocrystalline ZnO-TiO2

Pedhekar R. B., Raghuwanshi F. C., Kapse V. D.

Materials Science Poland

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2016

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Vol. 34, No. 3

571--581

EN

Nanocrystalline ZnO-TiO2 (with molar ratios 9:1, 7:3, 1:1, 3:7 and 1:9) were successfully synthesized by hydrothermal method. Synthesized materials were examined with the help of X-ray diffraction and transmission electron microscope. Liquid petroleum gas sensing characteristics of the ZnO-TiO2 films were investigated at different operating temperatures. The ZnO-TiO2 thick film (with 1:1 molar ratio) exhibited good response toward liquid petroleum gas as compared to other investigated compositions. Further, liquid petroleum gas sensing characteristics of CuO modified ZnO-TiO2 thick films were investigated. 0.2 M CuO modified ZnO-TiO2 thick film exhibited excellent liquid petroleum gas sensing characteristics such as higher response (~ 1637.49 at 185 °C) with quick response time (~30 s), low recovery time (~70 s), excellent repeatability and stability at low operating temperature.

10

E-nos (elektroniczny nos)

Krzyżewska I., Kozarska A.

LAB Laboratoria, Aparatura, Badania

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2016

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R. 21, nr 3

20--28

11

MWCNT-Pt nanocomposite as the active element of harmful gas sensors

Dobrzańska-Danikiewicz A. D., Łukowiec D., Wolany W., Procek M., Sękala A.

Archives of Materials Science and Engineering

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2016

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Vol. 81, nr 1

14--21

EN

Purpose: The goal of this paper is presentation of the variations in MWCNTs-Pt nanocomposite resistance which were examined in the presence of hydrogen with a rising concentration of, respectively, 1, 2, 3 and 4% H2 as well as nitrogen dioxide with a rising concentration of, respectively, 20, 100, 200, 400 ppm of NO2. Design/methodology/approach: Variations in electrical conductivity for the MWCNTs-Pt composite placed, alternately, in the atmosphere of gas and in the atmosphere of selected gases, were measured with a measuring station equipped with precision and inert gas reducers, mass flow meters, filtration systems of gas mixture and the studied mixture’s humidity and temperature control. An active layer of the transducer consisted of MWCNTsPt nanocomposite deposited thereon. All the measurements were carried out in the atmosphere of synthetic air (20% of O2 and 80% of N2) at 22.5°C. Findings: It was found based on the results obtained that system resistance is rising as hydrogen concentration is rising in the atmospheric air. The results of analogous examinations of variations in MWCNTs-Pt nanocomposite resistance carried out for a varying concentration of nitrogen dioxide in the atmosphere of synthetic air are opposite, because lowering system resistance was noted along with a heightening concentration of NO2. The best results were achieved for the nanocomposite presented in the article having a 5% mass concentration of platinum and with uniformly dispersed Pt particles on the surface of carbon nanoparticles. Practical implications: The outcomes presented signify the selectiveness of the applied system consisting of carbon nanotubes decorated with platinum nanoparticles. It means that this material can be used as the active element of harmful gas sensors. Originality/value: A carbon-metal MWCNTs-Pt nanocomposite with special electrical properties was fabricated in the course of research works, whose originality is based on the appropriately selected composition and the specific morphology.

12

Hydrogen Detection With a Gas Sensor Array – Processing and Recognition of Dynamic Responses Using Neural Networks

Gwiżdż P., Brudnik A., Zakrzewska K.

Metrology and Measurement Systems

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2015

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Vol. 22, nr 1

3--12

EN

An array consisting of four commercial gas sensors with target specifications for hydrocarbons, ammonia, alcohol, explosive gases has been constructed and tested. The sensors in the array operate in the dynamic mode upon the temperature modulation from 350°C to 500°C. Changes in the sensor operating temperature lead to distinct resistance responses affected by the gas type, its concentration and the humidity level. The measurements are performed upon various hydrogen (17-3000 ppm), methane (167-3000 ppm) and propane (167-3000 ppm) concentrations at relative humidity levels of 0-75%RH. The measured dynamic response signals are further processed with the Discrete Fourier Transform. Absolute values of the dc component and the first five harmonics of each sensor are analysed by a feed-forward back-propagation neural network. The ultimate aim of this research is to achieve a reliable hydrogen detection despite an interference of the humidity and residual gases.

13

Numerical and Experimental Analysis of the Response of a SAW Structure with WO3 Layers on Action of Carbon Monoxide

Hejczyk T., Urbańczyk M., Pustelny T., Jakubik W.

Archives of Acoustics

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2015

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Vol. 40, No. 1

19--24

EN

The paper presents the results of an analysis of gaseous sensors based on a surface acoustic wave (SAW) by means of the equivalent model theory. The applied theory analyzes the response of the SAW sensor in the steady state affected by carbon monoxide (CO) in air. A thin layer of WO3 has been used as a sensor layer. The acoustical replacing impedance of the sensor layer was used, which takes into account the profile of the concentration of gas molecules in the layer. Thanks to implementing the Ingebrigtsen equation, the authors determined analytical expressions for the relative changes of the velocity of the surface acoustic wave in the steady state. The results of the analysis have shown that there is an optimum thickness of the layer of CO sensor at which the acoustoelectric effect (manifested here as a change in the acoustic wave velocity) is at its highest. The theoretical results were verified and confirmed experimentally.

14

Zastosowanie laserów kaskadowych w układach do detekcji śladowych ilości gazów

Bielecki Z., Wojtas J., Stacewicz T.

Elektronika : konstrukcje, technologie, zastosowania

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2014

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Vol. 55, nr 11

44-46

PL

W pracy omówiono najczęściej stosowane układy spektroskopii absorpcyjnej przeznaczone do wykrywania śladowych ilości niebezpiecznych gazów, par materiałów wybuchowych i wybranych biomarkerów w wydychanym powietrzu. Szczególną uwagę poświęcono układom z komórkami wieloprzejściowymi, metodzie CRDS (ang. Cavity Ring Down Spectroscopy) i jej odmianom. Omówiono problemy związane z absorpcją promieniowania podczerwonego przez parę wodną, oraz konstrukcją tego typu czujników w celu uzyskania możliwie jak największej czułości. Przedstawiono celowość stosowania układów służących do filtracji, osuszania oraz dostarczenia tak przygotowanej próbki do modułów zatężania (tzw. prekoncentratorów), a następnie do czujników.

EN

The paper presents laser absorption spectroscopy systems, which are the most commonly used for detection of trace hazardous gases, explosives vapors and the biomarkers in exhaled air. Particular attention was paid to the systems of multi-pass cells and cavity enhanced spectroscopy (CRDS, CEAS). Disadvantage influence of water vapor and carbon dioxide was analyzed. These gases occur in breath with high concentration, which cause a limitation of the sensitivity. The attempt to minimization of this effect and experimental results are also described.

15

Investigation of electrocatalytic gas sensor properties in presence of chlorine

Strzelczyk A., Jasiński G., Chachulski B. A., Jasiński P.

Elektronika : konstrukcje, technologie, zastosowania

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2014

|

Vol. 55, nr 1

26-28

PL

W artykule przedstawiono wyniki badań czujnika elektrokatalitycznym w atmosferze zawierającej chlor. Prezentowane badania dotyczą czujnika wykonanego w technologii ceramicznej na bazie NASICONu posiadającego dwie okrągłe, platynowe elektrody. Wykonano pomiary w różnych temperaturach w celu wyznaczenia optymalnej temperatury działania czujnika.

EN

In this paper performance of an electrocatalytic sensor in presence of chlorine is investigated. Presented studies concern sensor prepared in ceramic technology based on NASICON as a solid electrolyte with two round shaped platinum electrodes. Measurements in different temperatures have been performed in order to determine optimal sensor working temperature.

16

Influence of the internal electrolyte composition on amperometric sulphur dioxide sensor properties

Strzelczyk A., Jasiński G., Chachulski B. A.

Elektronika : konstrukcje, technologie, zastosowania

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2014

|

Vol. 55, nr 1

23-26

PL

W tej pracy przedstawiono wyniki badań amperometrycznego czujnika dwutlenku siarki z ciekłym elektrolitem, siarczanortęciową elektrodę odniesienia oraz elektrodę roboczą w postaci membrany wykonanej z polimerowego elektrolitu stałego (Nafionu) pokrytej złotem. Głównym celem przedstawionych badań było określenie wpływu składu elektrolitu wewnętrznego na właściwości czujnika. Przebadano czujnik wypełniony 1M i 5M kwasem siarkowym.

EN

In this work investigation of an amperometric sulphur dioxide sensor with a liquid electrolyte, a mercury sulphate reference electrode and solid polymer electrolyte (Nafion) covered with gold as a working electrode properties is presented. The main goal of this research is to determine the influence of internal electrolyte composition on the sensor properties. Sensor filled with 1M and 5M sulphuric acid has been studied.

17

Studies of changes in electrical resistance of zinc oxide nanostructures under the influence of variable gaseous environments

Procek M., Pustelny T., Stolarczyk A., Maciak E.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2014

|

Vol. 62, nr 4

635--639

EN

The paper deals with the investigations concerning the influence of the changing gas environment on electrical resistance of zinc oxide (ZnO) nanostructures. The investigated structures are wide-gap semiconductors with the morphology of ZnO flower-shaped agglomerates of nanostructures. The resistance changes of these nanostructures were tested under the influence of various gases such as nitrogen dioxide (NO2), hydrogen (H2), ammonia (NH3) and also of humidity changes of carrier gases. To clarify the mechanisms of physicochemical processes in ZnO nanostructures during their interaction with gaseous environments, investigations were performed in two different carrier gases, viz. in synthetic air and in nitrogen. The study was carried out at a structure temperature of 200◦C.

18

Korekcja nieliniowości charakterystyk rezystancyjnych czujników gazów

Urzędniczok H.

Przegląd Elektrotechniczny

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2013

|

R. 89, nr 4

224-226

PL

Półprzewodnikowe rezystancyjne czujniki gazów, pomimo wysiłku konstruktorów, wykazują szereg niekorzystnych właściwości metrologicznych, w tym znaczną nieliniowość charakterystyk przetwarzania. W artykule opisano metodę wyznaczania charakterystyki przetwarzania dla pewnej klasy czujników tego typu i przedstawiono uzyskane wyniki. Zaproponowano analogowy układ kondycjonowania pozwalający na kształtowanie charakterystyk przetwarzania części analogowej toru pomiarowego, a w szczególności uzyskanie znacznie lepszej liniowości w szerokim zakresie stężeń gazów. Zamieszczono zależności opisujące układ. Przedstawiono charakterystyki toru pomiarowego uzyskane przy zastosowaniu czujnika typu TGS 3870, przeznaczonego do zastosowań w miernikach stężenia tlenku węgla i metanu. Proponowany układ może znaleźć zastosowanie również dla innych typów półprzewodnikowych, rezystancyjnych czujników gazów.

EN

The transfer curves of gas sensors based on semiconductor sensing materials (like SiO2) usually are strongly nonlinear. The characteristics given in data sheets are not precise enough to design a transducer for gas concentration measurements, therefore an individual calibration of the sensor is needed. This paper describes a method of determination of the transfer curve for selected types of semiconductor resistive gas sensors. There is also presented an electronic conditioning device, designed to considerable improve linearity for the measuring transducer, composed of the sensor and conditioning device. This device was applied to TGS3870 sensor, which is sensitive to carbon monoxide and methane. Linearity of transfer curves is considerably better in comparison with that ones for the sensor.

19

Urządzenia do monitorowania gazów rozpuszczonych w oleju transformatorowym

Malewski R.

Pomiary Automatyka Kontrola

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2013

|

R. 59, nr 2

93--96

PL

Czujniki wykrywające wodór i inne gazy w oleju działają na różnych zasadach, co stanowi o ich zaletach i ograniczeniach. Dotychczas głównym ograniczeniem powszechnego zastosowania układów monitorujących zawartość gazów w oleju była wysoka cena. Opracowanie układu monitorującego w oparciu o palladowy czujnik zawartości oleju uprościło konstrukcję i obniżyło cenę takiego układu do poziomu uzasadniającego jego stosowanie do transformatorów średniej mocy.

EN

Gas in oil monitoring devices for condition assessment of HV power-transformer insulation have been reviewed for their measuring characteristics, complexity of design and cost. More advanced, complex and expensive monitors have been installed on large and strategically important transformers. However, the medium-power transformers constitute majority of transformer population in electric-power systems, but the high price of monitoring devices prevented their application to the medium-power units. The recently designed inexpensive Hydrogen-in-oil monitor uses a Palladium alloy sensor that reduces complexity and cost of this monitor effectively. Installation of such a simple monitoring system on medium-power transformers is economically justified, in particular on units with service-aged paper-oil insulation. The paper describes on-line diagnostics of power transformers with various measuring devices. Such diagnostics is based on measurements of hydrogen, carbon oxides, gas chromatography, photo-acoustic gas spectrography.

20

Gas sensing performance of nanocrystalline ZnO prepared by a simple route

Murade P. A., Sangawar V. S., Chaudhari G. N., Kapse V. D., Bajpeyee A. U.

Materials Science Poland

|

2013

|

Vol. 31, No. 3

298--305

EN

The nanocrystalline powders of pure and Al3+-doped ZnO with hexagonal structure were prepared by a simple hydrothermal decomposition route. The structure and crystal phase of the powders were characterized by X-ray diffraction (XRD) and the microstructure by transmission electron microscopy (TEM). All the compositions exhibited a single phase, suggesting a formation of solid solution between Al2O3 and ZnO. DC electrical properties of the prepared nanoparticles were studied by DC conductivity measurements. The indirect heating structure sensors based on pure and doped ZnO as sensitive materials were fabricated on an alumna tube with Au electrodes. Gas-sensing properties of the sensor elements were measured as a function of concentration of dopant, operating temperature and concentrations of the test gases. The pure ZnO exhibited high response to NH3 gas at an operating temperature of 200 C. Doping of ZnO with Al3+ increased its response towards NH3 and the Al3+-doped ZnO (3.0 wt% Al2O3) showed the maximum response at 175 C. The selectivity of the sensor elements for NH3 against different reducing gases like LPG, H2S and H2 was studied. The results on response and recovery time were also discussed.