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Search results for: GAS SENSOR
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Efficiency of linear and non-linear classifiers for gas identification from electrocatalytic gas sensor
PublicationElectrocatalytic gas sensors belong to the family of electrochemical solid state sensors. Their responses are acquired in the form of I-V plots as a result of application of cyclic voltammetry technique. In order to obtain information about the type of measured gas the multivariate data analysis and pattern classification techniques can be employed. However, there is a lack of information in literature about application of such...
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Efficiency of gas mixtures detection by resistive gas sensors
PublicationResistive gas sensors are very popular and are commonly used to detect various gases and their mixtures. Theeir main disadvantage is very limited selectivity. Practical use of gas sensors in environenmental applications requires determination of concentration of a few mixed gases at the same time. We would like to present recent results of gas detection improvement by utilizing a single gas sensor and additional measurements to...
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EFFICIENCY OF GAS MIXTURES DETECTION BY RESISTIVE GAS SENSORS
PublicationResistive gas sensors are very popular and are commonly used to detect various gases and their mixtures. Their main disadvantage is very limited selectivity. Practical use of gas sensors in environmental applications (e.g., in sewage systems to protect workers, in air conditioning systems to monitor atmosphere quality) requires determination of concentration of a few mixed gases at the same time. We would like to present recent...
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Gas sensors based on conducting polymers-recent developments
PublicationThis work discusses sensing performance dependence of PEDOT polymer and its composites on the counter ions used in the polymerization process. The sensors based on PEDOT-RGO composite show reversible response to NO2, while on PEDOT/LiClO4 irreversible. As a result, PEDOT-RGO could be used as a typical gas sensor, while sensor based PEDOT/LiClO4 could be used as an integrating gas sensor, also known as an accumulating gas sensor....
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Gas sampling system for matrix of semiconductor gas sensors
PublicationSemiconductor gas sensors are popular commercial sensors applied in numerous gas detection systems. They are reliable, small, rugged and inexpensive. However, there are a few problem limiting the wider use of such sensors. Semiconductor gas sensor usually exhibits a low selectivity, low repeatability, drift of response, strong temperature and moisture influence on sensor properties. Sample flow rate is one of the parameters that...
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Selectivity of amperometric gas sensors in multicomponent gas mixtures
PublicationIn recent years smog and poor air quality became a growing environmental problem. There is a need to continuously monitor the quality of air. The lack of selectivity is one of the most important problems limiting the use of gas sensors for this purpose. In this study, a selectivity of the six amperometric gas sensors is being investigated. Calibration of sensors has been performed in order to find a correlation between concentration...
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Analytical fluctuation enhanced sensing by resistive gas sensors
PublicationResistance fluctuations across polarised resistive gas sensors were studied in detail to evaluate sensor working conditions for detecting methane and ammonia at various concentrations. The 1/f noise component typically dominates other noise sources up to a few kHz and can be utilised to improve gas selectivity when compared with measurements of the sensor DC resistance. The Arrhenius plot was created and the activation energy for...
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Identification of defected sensors in an array of amperometric gas sensors
PublicationPurpose Amperometric gas sensors are commonly used in air quality monitoring in long-term measurements. Baseline shift of sensor responses and power failure may occur over time, which is an obstacle for reliable operation of the entire system. The purpose of this study is to check the possibility of using PCA method to detect defected samples, identify faulty sensor and correct the responses of the sensor identified as faulty. Design/methodology/approach In...
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Scalable Measurement System for Multiple Impedance Gas Sensors
PublicationAuthor proposes scalable architecture of the measurement system for gas sensor with impedance dependance of the gas concentration. The main part of the system is a single-board impedance analyser. The number of analysers working in parallel can be configured according to specific application. The system is controlled by a single computer which organises the measurement cycle and store the acquired measurement data. The system is...
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Problems of gas detection by resistance fluctuations in gas sensors
PublicationPrzedstawiono problemy budowy dystrybutora gazów oraz próbek zapachowych do badań sensorów gazu. Podano układ elektroniczny wykorzystywany do rejestracji fluktuacji rezystancji obserwowany w czujnikach gazu. Załączono przykładowe wyniki obserwacji sygnałów losowych.
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An electronic nose based on the semiconducting and electrochemical gas sensors
PublicationThe practical application of human nose for fragrance recognition is severely limited by the fact that our sense of smell is subjective and gets tired easily. Consequently, there is a significant need for an instrument that can be a substitution of the human sense of smell. Development of an electronic nose devices is an active area of research starting from pioneering research of Dodd and Persuad in the mid-1980s. Such systems...
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Resistive gas sensors – Perspectives on selectivity and sensitivity improvement
PublicationResistive gas sensors are very popular and relatively inexpensive; they can operate at elevated or room temperature for years on end. The main disadvantage of resistive gas sensors is their limited selectivity and sensitivity, but various methods have been applied to improve their behavior. The composition of the porous gas sensing layer, or changes in the sensor’s operating temperature, can enhance the gas detection ability. Furthermore, emerging...
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IMPEDANCE MEASUREMENT MODULE FOR GAS SENSORS WITH TEMPERATURE CONDITIONING FEATURE
PublicationThe paper presents an impedance measurement module which is aimed for gas sensor. Sensor’s heater temperature conditioning and modulation feature is available in order to allow implementation of different techniques improving selectivity and sensitivity of gas sensors. The measurement module uses three-parameter sine-fitting technique for impedance measurement. To monitor sensor temperature, the resistance of the sensor’s heater...
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Techniques of acquiring additional features of the responses of individual gas sensors
PublicationGas sensors usually exhibit lack of selectivity, require fre quent calibration, exhibit drift of the response and a lot of factors, such as humidity or ambient temperature, influen ce their performance. Different approaches can be used to overcome this shortcomings. Building arrays of different sensors and usage of pattern recognition methods to analyze responses of elements...
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Chemiresistive gas sensors based on carbon nanotubes - fabrication and application
PublicationMany types of sensors have been invented to identify and quantify chemical contamination in the gas phase. Sensors based on carbon nanotubes are particularly attractive because of their wide range of applicaions and potential use in electronic nose that can be controlled using algorithms of Artificial Intelligence. Sensor functions, fabrication and selected applications are reviewed and discussed with focus on chemiresistors. Drawbacks...
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Ammonia Gas Sensors: Comparison of Solid-State and Optical Methods
PublicationHigh precision and fast measurement of gas concentrations is important for both understanding and monitoring various phenomena, from industrial and environmental to medical and scientific applications. This article deals with the recent progress in ammonia detection using in-situ solid-state and optical methods. Due to the continuous progress in material engineering and optoelectronic technologies, these methods are among the most...
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Chemiresistive gas sensors based on carbon nanotubes - fabrication and application
PublicationOpisano przygotowanie i możliwości zastosowania chemirezystancyjnych czujników gazów wykonanych z nanorurek węglowych.
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Amperometric gas sensors with elektrodes chemically deposited on Nafion membrane
PublicationW pracy przedstawiono opis metod otrzymywania elektrod pracujących w czujnikach amperometrycznych gazów z elektrolitem ciekłym. Zaprezentowano metody chemiczne takie jak: metoda impregnacji-redukcji i metoda Takenaka-Torikai. Przedstawiono przegląd konstrukcji czujnikowych gazowych z elektrodami tego typu.
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Resistance Noise Higher-Order Spectrums in Nanoparticle Gas Sensors.
PublicationPrzedstawiono badania fluktuacji rezystancji sensora gazu wykonanego z nanocząstek WO3. Stwierdzono występowanie składowych o rozkładzie prawdopodobieństwa różnym od rozkładu Gaussa. W celu zwiększenia czułości i selektywności wykrywanych gazów zastosowan do analizy obserwowanych fluktuacji spektra wyższych rzędów.
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Application of a Gas Sensor Array to Effectiveness Monitoring of Air Contaminated with Toluene Vapors Absorption Process
PublicationThis 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...