scholarly journals Field Study of Metal Oxide Semiconductor Gas Sensors in Temperature Cycled Operation for Selective VOC Monitoring in Indoor Air

Atmosphere ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 647
Author(s):  
Tobias Baur ◽  
Johannes Amann ◽  
Caroline Schultealbert ◽  
Andreas Schütze
Keyword(s):  
Air Quality ◽  
Metal Oxide ◽  
Gas Sensor ◽  
Gas Sensors ◽  
Indoor Air ◽  
Ambient Air ◽  
Quantitative Agreement ◽  
Metal Oxide Semiconductor ◽  
Oxide Semiconductor ◽  
High Temporal Resolution

More and more metal oxide semiconductor (MOS) gas sensors with digital interfaces are entering the market for indoor air quality (IAQ) monitoring. These sensors are intended to measure volatile organic compounds (VOCs) in indoor air, an important air quality factor. However, their standard operating mode often does not make full use of their true capabilities. More sophisticated operation modes, extensive calibration and advanced data evaluation can significantly improve VOC measurements and, furthermore, achieve selective measurements of single gases or at least types of VOCs. This study provides an overview of the potential and limits of MOS gas sensors for IAQ monitoring using temperature cycled operation (TCO), calibration with randomized exposure and data-based models trained with advanced machine learning. After lab calibration, a commercial digital gas sensor with four different gas-sensitive layers was tested in the field over several weeks. In addition to monitoring normal ambient air, release tests were performed with compounds that were included in the lab calibration, but also with additional VOCs. The tests were accompanied by different analytical systems (GC-MS with Tenax sampling, mobile GC-PID and GC-RCP). The results show quantitative agreement between analytical systems and the MOS gas sensor system. The study shows that MOS sensors are highly suitable for determining the overall VOC concentrations with high temporal resolution and, with some restrictions, also for selective measurements of individual components.

scholarly journals Calibration of Metal Oxide Semiconductor Gas Sensors by High School Students

2021 ◽  
Vol 17 (04) ◽  
pp. 4
Author(s):  
Sebastian Höfner ◽  
Andreas Schütze ◽  
Michael Hirth ◽  
Jochen Kuhn ◽  
Benjamin Brück
Keyword(s):  
High School Students ◽  
Air Quality ◽  
Metal Oxide ◽  
Gas Sensor ◽  
Gas Sensors ◽  
Objective Assessment ◽  
Metal Oxide Semiconductor ◽  
Oxide Semiconductor ◽  
Calibration Process ◽  
Wide Range

A wide range of pollutants cannot be perceived with human senses, which is why the use of gas sensors is indispensable for an objective assessment of air quality. Since many pollutants are both odorless and colorless, there is a lack of awareness, in particular among students. The project SUSmobil (funded by DBU – Deutsche Bundesstiftung Umwelt) aims to change this. In three modules on the topic of gas sensors and air quality, the students (a) learn the functionality of a metal oxide semiconductor (MOS) gas sensor, (b) perform a calibration process and (c) carry out environmental measurements with calibrated sensors. Based on these introductory experiments, the students are encouraged to develop their own environmental questions. In this paper, the student experiment for the calibration of a MOS gas sensor for ethanol is discussed. The experiment, designed as an HTML-based learning, addresses both theoretical and practical aspects of a typical sensor calibration process, consisting of data acquisition, feature extraction and model generation. In this example, machine learning is used for generating the evaluation model as existing physical models are not sufficiently exact.

scholarly journals Synthesis of Metal Oxide Semiconductor Nanostructures for Gas Sensors

Gas Sensors ◽  
2020 ◽  
Author(s):  
Nazar Abbas Shah ◽  
Majeed Gul ◽  
Murrawat Abbas ◽  
Muhammad Amin
Keyword(s):  
Metal Oxide ◽  
Gas Sensors ◽  
Semiconductor Nanostructures ◽  
Metal Oxide Semiconductor ◽  
Oxide Semiconductor

scholarly journals A Prototype to Detect the Alcohol Content of Beers Based on an Electronic Nose

Sensors ◽  
2019 ◽  
Vol 19 (11) ◽  
pp. 2646 ◽  
Author(s):  
Henike Guilherme Jordan Voss ◽  
José Jair Alves Mendes Júnior ◽  
Murilo Eduardo Farinelli ◽  
Sergio Luiz Stevan
Keyword(s):  
Metal Oxide ◽  
Electronic Nose ◽  
Gas Sensors ◽  
Metal Oxide Semiconductor ◽  
Oxide Semiconductor ◽  
Alcohol Content ◽  
Electronic Noses

Due to the emergence of new microbreweries in the Brazilian market, there is a need to construct equipment to quickly and accurately identify the alcohol content in beverages, together with a reduced marketing cost. Towards this purpose, the electronic noses prove to be the most suitable equipment for this situation. In this work, a prototype was developed to detect the concentration of ethanol in a high spectrum of beers presents in the market. It was used cheap and easy-to-acquire 13 gas sensors made with a metal oxide semiconductor (MOS). Samples with 15 predetermined alcohol contents were used for the training and construction of the models. For validation, seven different commercial beverages were used. The correlation (R2) of 0.888 for the MLR (RMSE = 0.45) and the error of 5.47% for the ELM (RMSE = 0.33) demonstrate that the equipment can be an effective tool for detecting the levels of alcohol contained in beverages.

Detection of triacetone triperoxide using temperature cycled metal-oxide semiconductor gas sensors

2015 ◽  
Vol 212 (6) ◽  
pp. 1289-1298 ◽  
Author(s):  
Johannes Warmer ◽  
Patrick Wagner ◽  
Michael J. Schöning ◽  
Peter Kaul
Keyword(s):  
Metal Oxide ◽  
Gas Sensors ◽  
Metal Oxide Semiconductor ◽  
Oxide Semiconductor ◽  
Triacetone Triperoxide ◽  
Semiconductor Gas Sensors
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