Journal articles on the topic 'Sensor measurements'
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1
Hagemeier, Sebastian, Markus Schake, and Peter Lehmann. "Sensor characterization by comparative measurements using a multi-sensor measuring system." Journal of Sensors and Sensor Systems 8, no. 1 (February 28, 2019): 111–21. http://dx.doi.org/10.5194/jsss-8-111-2019.
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Abstract. Typical 3-D topography sensors for the measurement of surface structures in the micro- and nanometre range are atomic force microscopes (AFMs), tactile stylus instruments, confocal microscopes and white-light interferometers. Each sensor shows its own transfer behaviour. In order to investigate transfer characteristics as well as systematic measurement effects, a multi-sensor measuring system is presented. With this measurement system comparative measurements using five different topography sensors are performed under identical conditions in a single set-up. In addition to the concept of the multi-sensor measuring system and an overview of the sensors used, surface profiles obtained from a fine chirp calibration standard are presented to show the difficulties of an exact reconstruction of the surface structure as well as the necessity of comparative measurements conducted with different topography sensors. Furthermore, the suitability of the AFM as reference sensor for high-precision measurements is shown by measuring the surface structure of a blank Blu-ray disc.
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Bílek, Jiří, Ondřej Bílek, Petr Maršolek, and Pavel Buček. "Ambient Air Quality Measurement with Low-Cost Optical and Electrochemical Sensors: An Evaluation of Continuous Year-Long Operation." Environments 8, no. 11 (October 27, 2021): 114. http://dx.doi.org/10.3390/environments8110114.
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Sensor technology is attractive to the public due to its availability and ease of use. However, its usage raises numerous questions. The general trustworthiness of sensor data is widely discussed, especially with regard to accuracy, precision, and long-term signal stability. The VSB-Technical University of Ostrava has operated an air quality sensor network for more than two years, and its large sets of valid results can help in understanding the limitations of sensory measurement. Monitoring is focused on the concentrations of dust particles, NO2, and ozone to verify the impact of newly planted greenery on the reduction in air pollution. The sensor network currently covers an open field on the outskirts of Ostrava, between Liberty Ironworks and the nearby ISKO1650 monitoring station, where some of the worst air pollution levels in the Czech Republic are regularly measured. In the future, trees should be allowed to grow over the sensors, enabling assessment of the green barrier effect on air pollution. As expected, the service life of the sensors varies from 1 to 3 years; therefore, checks are necessary both prior to the measurement and regularly during operation, verifying output stability and overall performance. Results of the PMx sensory measurements correlated well with the reference method. Concentration values measured by NO2 sensors correlated poorly with the reference method, although timeline plots of concentration changes were in accordance. We suggest that a comparison of timelines should be used for air quality evaluations, rather than particular values. The results showed that the sensor measurements are not yet suitable to replace the reference methods, and dense sensor networks proved useful and robust tools for indicative air quality measurements (AQM).
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Ziebarth, Mathias, Niclas Zeller, Michael Heizmann, and Franz Quint. "Modeling the unified measurement uncertainty of deflectometric and plenoptic 3-D sensors." Journal of Sensors and Sensor Systems 7, no. 2 (September 28, 2018): 517–33. http://dx.doi.org/10.5194/jsss-7-517-2018.
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Abstract. In this paper we propose new models of two complementary optical sensors to obtain 2.5-D measurements of opaque surfaces: a deflectometric and a plenoptic sensor. The deflectometric sensor uses active triangulation and works best on specular surfaces, while the plenoptic sensor uses passive triangulation and works best on textured, diffusely reflecting surfaces. We propose models to describe the measurement uncertainties of the sensors for specularly to diffusely reflecting surfaces under consideration of typical disturbances like ambient light or vibration. The predicted measurement uncertainties of both sensors can be used to obtain optimized measurements uncertainties for varying surface properties on the basis of a combined sensor system. The models are validated exemplarily based on real measurements.
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Ritter, Greice Scherer, Eliezer Oliveira Cavalheiro, Ronaldo Barcelos e. Silva, Leonardo Da Rosa Schmidt, and Silvana Maldaner. "Medidas de temperatura em ambiente interno usando a Plataforma Arduino." Ciência e Natura 42 (February 7, 2020): 35. http://dx.doi.org/10.5902/2179460x40637.
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The paper presents the results of a study with temperature measurements using low cost sensors connected to an Arduino microcontroller. To perform the study, three sensors widely used for monitoring environmental conditions with Arduino. The selected sensors were the LM35DZ (analog sensor) and DHT11 and DHT22 (digital sensors). The LM35DZ sensor is a sensor known to be an analog sensor that has linear temperature response with voltage. The DHT11 sensor measures temperature and humidity simultaneously. To measure temperature the DHT11 sensor uses a temperature-sensitive resistor and has a measurement range from 0 to 50 °C, with an uncertainty ± 2% ° C. The DHT22 has a measurement range -40 to 80 ° C and an uncertainty ± 1% ° C. Simultaneous temperature measurements with the three sensors showed good performance in indoor situations, showing the maximum and minimum temperatures of a daily temperature cycle.
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Benaissa, Bedr-Eddine, Fedoua Lahfa, Khatir Naima, Giulio Lorenzini, Mustafa Inc, and Younes Menni. "Detection and Cooperative Communications for Deployment Sensor Networks." Traitement du Signal 38, no. 3 (June 30, 2021): 555–64. http://dx.doi.org/10.18280/ts.380303.
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In a sensor network, and more specifically with a single-hop deployment policy, sensor measurements contain a lot of redundancy either in the measurement dimensions of a single sensor, or between the measurement dimensions of different sensors due to of the spatial correlation either in the temporal dimension of the measurements. The goal is to reduce this redundancy by deploying fewer sensors, while ensuring high measurement accuracy and maximizing service life. The proposed method minimizes the complexity in terms of communication and calculation and maximizes the lifetime of the network based on an aggregation and consensus system to reduce the spatio-temporal dimension of the data captured and consequently the number of sensors deployed. The results show a visible performance compared to the standard method of transmission on the free platform of the COOJA/Contiki simulator allowing to simulate network connections of wireless sensors and to interact with them.
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Buček, Pavel, Petr Maršolek, and Jiří Bílek. "Low-Cost Sensors for Air Quality Monitoring - the Current State of the Technology and a Use Overview." Chemistry-Didactics-Ecology-Metrology 26, no. 1-2 (December 1, 2021): 41–54. http://dx.doi.org/10.2478/cdem-2021-0003.
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Abstract In recent years the monitoring of air quality using cheap sensors has become an interesting alternative to conventional analytical techniques. Apart from vast price differences conventional techniques need to be performed by the trained personnel of commercial or research laboratories. Sensors capable of measuring dust, ozone, nitrogen and sulphur oxides, or other air pollutants are relatively simple electronic devices, which are comparable in size to a mobile phone. They provide the general public with the possibility to monitor air quality which can contribute to various projects that differ in regional scale, commercial funding or community-base. In connection with the low price of sensors arises the question of the quality of measured data. This issue is addressed by a number of studies focused on comparing the sensor data with the data of reference measurements. Sensory measurement is influenced by the monitored analyte, type and design of the particular sensor, as well as by the measurement conditions. Currently sensor networks serve as an additional source of information to the network of air quality monitoring stations, where the density of the network provides concentration trends in the area that may exceed specific measured values of pollutant concentrations and low uncertainty of reference measurements. The constant development of all types of sensors is leading to improvements and the difference in data quality between sensors and conventional monitoring techniques may be reduced.
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Pillarz, Marc, Axel von Freyberg, Dirk Stöbener, and Andreas Fischer. "Gear Shape Measurement Potential of Laser Triangulation and Confocal-Chromatic Distance Sensors." Sensors 21, no. 3 (January 30, 2021): 937. http://dx.doi.org/10.3390/s21030937.
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The demand for extensive gear shape measurements with single-digit µm uncertainty is growing. Tactile standard gear tests are precise but limited in speed. Recently, faster optical gear shape measurement systems have been examined. Optical gear shape measurements are challenging due to potential deviation sources such as the tilt angles between the surface normal and the sensor axis, the varying surface curvature, and the surface properties. Currently, the full potential of optical gear shape measurement systems is not known. Therefore, laser triangulation and confocal-chromatic gear shape measurements using a lateral scanning position measurement approach are studied. As a result of tooth flank standard measurements, random effects due to surface properties are identified to primarily dominate the achievable gear shape measurement uncertainty. The standard measurement uncertainty with the studied triangulation sensor amounts to >10 µm, which does not meet the requirements. The standard measurement uncertainty with the confocal-chromatic sensor is <6.5 µm. Furthermore, measurements on a spur gear show that multiple reflections do not influence the measurement uncertainty when measuring with the lateral scanning position measurement approach. Although commercial optical sensors are not designed for optical gear shape measurements, standard uncertainties of <10 µm are achievable for example with the applied confocal-chromatic sensor, which indicates the further potential for optical gear shape measurements.
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Gokcay, Mehmet Asim, and Chingiz Hajiyev. "Comparison of TRIAD+EKF and TRIAD+UKF Algorithms for Nanosatellite Attitude Estimation." WSEAS TRANSACTIONS ON SYSTEMS AND CONTROL 17 (May 4, 2022): 201–6. http://dx.doi.org/10.37394/23203.2022.17.23.
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Two most commonly used sensors on nanosatellites are magnetometer and sun sensor. In this paper, magnetometer and sun sensor measurements are combined gyro measurements to produce enhanced attitude estimation. Tri-Axial Attitude Determination (TRIAD) algorithm is used with Kalman filter to form a complete attitude filter. Sun sensor and magnetometer measurements are selected as inputs to TRIAD algorithm and output is fed to Kalman filter as a measurement. Two different Kalman filters, extended and unscented, are used with TRIAD algorithm. A comparison is given between performances of both Kalman filter.
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Lee, JeeEun, and Sun K. Yoo. "Radar-Based Detection of Respiration Rate with Adaptive Harmonic Quefrency Selection." Sensors 20, no. 6 (March 13, 2020): 1607. http://dx.doi.org/10.3390/s20061607.
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Continuous respiration monitoring is important for predicting a potential disease. Due to respiration measurements using contact sensors, it is difficult to achieve continuous measurement because the sensors are inconvenient to attach. In this study, a radar sensor was used for non-contact respiration measurements. The radar sensor had a high precision and could even be used in the dark. It could also be used continuously regardless of time and place. The radar sensor relied on the periodicity of respiration to detect the respiration rate. A respiration adaptive interval was set and the respiration rate was detected through harmonic quefrency selection. As a result, it was confirmed that there was no difference between the respiratory rate measured using a respiration belt and the respiratory rate detected using a radar sensor. Furthermore, case studies on changes in the radar position and about measurement for long periods confirmed that the radar sensor could detect respiration rate continuously regardless of the position and measurement duration.
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Sanati, Mehdi, Allen Sandwell, Hamid Mostaghimi, and Simon Park. "Development of Nanocomposite-Based Strain Sensor with Piezoelectric and Piezoresistive Properties." Sensors 18, no. 11 (November 6, 2018): 3789. http://dx.doi.org/10.3390/s18113789.
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Sensors provide aninterface between mechanical systems and the physical world. With the move towardsIndustry 4.0 and cyber-physical systems, demands for cost-effective sensors are rapidly increasing. Conventional sensors used for monitoring manufacturing processes are often bulky and need complex processes. In this study, a novel high-sensitive nanocomposite-based sensor is developed for measuring strain. The developed sensor is comprised of polyvinylidene fluoride (PVDF) as a piezoelectric polymer matrix, and embedded carbon nanotube (CNT) nanoparticles creating a conductive network. Exhibiting both piezoelectric and piezoresistive properties, the developed sensors are capable of strain measurement over a wide frequency band, including static and dynamic measurements. The piezoresistive and piezoelectric properties are fused to improve the overall sensitivity and frequency bandwidth of the sensor. To simulate the sensor, a 3D random walk model and a 2D finite element (FE) model are used to predict the electrical resistivity and the piezoelectric characteristics of the sensor, respectively. The developed models are verified with the experimental results. The developed nanocomposite sensors were employed for strain measurement of a cantilever beam under static load, impulse excitation, free and forced vibrations, collecting both piezoelectric and piezoresistive properties measurements. The obtained signals were fused and compared with those of a reference sensor. The results show that the sensor is capable of strain measurement in the range of 0–10 kHz, indicating its effectiveness at measuring both static and high frequency signals which is an important feature of the sensor.
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Kotarski, Mateusz, and Janusz Smulko. "Fluctuation Enhanced Gas Sensing at Modulated Temperature of Gas Sensor." International Journal of Measurement Technologies and Instrumentation Engineering 2, no. 2 (April 2012): 41–52. http://dx.doi.org/10.4018/ijmtie.2012040104.
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Taguchi gas sensors are commonly used to measure gas concentration. The standard detection method utilizes only changes of sensor DC resistance to determine various gases concentration. Unfortunately, such technique leads to false results due to cross-sensitivity of gas sensors at presence of other gases. Such adverse effects can be reduced by applying fluctuation enhanced sensing and temperature modulation of the sensor what allows to gather more information about ambient atmosphere than the sensor DC resistance only. The measurement setup of voltage fluctuations across the gas sensor as well as the selected measurements results of DC resistance under temperature modulation are presented. New indicators of gas detection have been proposed which utilize voltage fluctuations and DC resistance measurements at two selected different temperatures of the gas sensor.
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Domínguez-Niño, Jesús María, Jordi Oliver-Manera, Gerard Arbat, Joan Girona, and Jaume Casadesús. "Analysis of the Variability in Soil Moisture Measurements by Capacitance Sensors in a Drip-Irrigated Orchard." Sensors 20, no. 18 (September 7, 2020): 5100. http://dx.doi.org/10.3390/s20185100.
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Among the diverse techniques for monitoring soil moisture, capacitance-type soil moisture sensors are popular because of their low cost, low maintenance requirements, and acceptable performance. However, although in laboratory conditions the accuracy of these sensors is good, when installed in the field they tend to show large sensor-to-sensor differences, especially under drip irrigation. It makes difficult to decide in which positions the sensors are installed and the interpretation of the recorded data. The aim of this paper is to study the variability involved in the measurement of soil moisture by capacitance sensors in a drip-irrigated orchard and, using this information, find ways to optimize their usage to manage irrigation. For this purpose, the study examines the uncertainties in the measurement process plus the natural variability in the actual soil water dynamics. Measurements were collected by 57 sensors, located at 10 combinations of depth and position relative to the dripper. Our results showed large sensor-to-sensor differences, even when installed at equivalent depth and coordinates relative to the drippers. In contrast, differences among virtual sensors simulated using a HYDRUS-3D model at those soil locations were one order of magnitude smaller. Our results highlight, as a possible cause for the sensor-to-sensor differences in the measurements by capacitance sensors, the natural variability in size, shape, and centering of the wet area below the drippers, combined with the sharply defined variation in water content at the soil scale perceived by the sensors.
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Genser, Simon, Stefan Muckenhuber, Selim Solmaz, and Jakob Reckenzaun. "Development and Experimental Validation of an Intelligent Camera Model for Automated Driving." Sensors 21, no. 22 (November 15, 2021): 7583. http://dx.doi.org/10.3390/s21227583.
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The virtual testing and validation of advanced driver assistance system and automated driving (ADAS/AD) functions require efficient and realistic perception sensor models. In particular, the limitations and measurement errors of real perception sensors need to be simulated realistically in order to generate useful sensor data for the ADAS/AD function under test. In this paper, a novel sensor modeling approach for automotive perception sensors is introduced. The novel approach combines kernel density estimation with regression modeling and puts the main focus on the position measurement errors. The modeling approach is designed for any automotive perception sensor that provides position estimations at the object level. To demonstrate and evaluate the new approach, a common state-of-the-art automotive camera (Mobileye 630) was considered. Both sensor measurements (Mobileye position estimations) and ground-truth data (DGPS positions of all attending vehicles) were collected during a large measurement campaign on a Hungarian highway to support the development and experimental validation of the new approach. The quality of the model was tested and compared to reference measurements, leading to a pointwise position error of 9.60% in the lateral and 1.57% in the longitudinal direction. Additionally, the modeling of the natural scattering of the sensor model output was satisfying. In particular, the deviations of the position measurements were well modeled with this approach.
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Onofrei, Elena, Teodor-Cezar Codau, Gauthier Bedek, Daniel Dupont, and Cedric Cochrane. "Textile sensor for heat flow measurements." Textile Research Journal 87, no. 2 (July 22, 2016): 165–74. http://dx.doi.org/10.1177/0040517515627167.
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This paper describes the concept of creating and testing of a textile heat flow sensor in order to determine the amount of heat exchanged between the human body and its environment. The main advantage of this sensor is the permeability to moisture, which allows taking into account the evaporation phenomenon, contrary to the traditional heat flow sensors. Another property related to this new sensor is its flexibility conferred by the textile substrate, which allows it to be applied on deformable surfaces.
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Ryan, Wendy A., Nolan J. Doesken, and Steven R. Fassnacht. "Evaluation of Ultrasonic Snow Depth Sensors for U.S. Snow Measurements." Journal of Atmospheric and Oceanic Technology 25, no. 5 (May 1, 2008): 667–84. http://dx.doi.org/10.1175/2007jtecha947.1.
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Abstract Ultrasonic snow depth sensors are examined as a low cost, automated method to perform traditional snow measurements. In collaboration with the National Weather Service, nine sites across the United States were equipped with two manufacturers of ultrasonic depth sensors: the Campbell Scientific SR-50 and the Judd Communications sensor. Following standard observing protocol, manual measurements of 6-h snowfall and total snow depth on ground were also gathered. Results show that the sensors report the depth of snow directly beneath on average within ±1 cm of manual observations. However, the sensors tended to underestimate the traditional total depth of snow-on-ground measurement by approximately 2 cm. This is mainly attributed to spatial variability of the snow cover caused by factors such as wind scour and wind drift. After assessing how well the sensors represented the depth of snow on the ground, two algorithms were created to estimate the traditional measurement of 6-h snowfall from the continuous snow depth reported by the sensors. A 5-min snowfall algorithm (5MSA) and a 60-min snowfall algorithm (60MSA) were created. These simple algorithms essentially sum changes in snow depth using 5- and 60-min intervals of change and sum positive changes over the traditional 6-h observation periods after compaction routines are applied. The algorithm results were compared to manual observations of snowfall. The results indicated that the 5MSA worked best with the Campbell Scientific sensor. The Campbell sensor appears to estimate snowfall more accurately than the Judd sensor due to the difference in sensor resolution. The Judd sensor results did improve with the 60-min snowfall algorithm. This technology does appear to have potential for collecting useful and timely information on snow accumulation, but determination of snowfall to the current requirement of 0.1 in. (0.25 cm) is a difficult task.
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Maurizi, Marco, Janko Slavič, Filippo Cianetti, Marko Jerman, Joško Valentinčič, Andrej Lebar, and Miha Boltežar. "Dynamic Measurements Using FDM 3D-Printed Embedded Strain Sensors." Sensors 19, no. 12 (June 12, 2019): 2661. http://dx.doi.org/10.3390/s19122661.
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3D-printing technology is opening up new possibilities for the co-printing of sensory elements. While quasi-static research has shown promise, the dynamic performance has yet to be researched. This study researched smart 3D structures with embedded and printed sensory elements. The embedded strain sensor was based on the conductive PLA (Polylactic Acid) material. The research was focused on dynamic measurements of the strain and considered the theoretical background of the piezoresistivity of conductive PLA materials, the temperature effects, the nonlinearities, the dynamic range, the electromagnetic sensitivity and the frequency range. A quasi-static calibration used in the dynamic measurements was proposed. It was shown that the temperature effects were negligible, the sensory element was linear as long as the structure had a linear response, the dynamic range started at ∼ 30 μ ϵ and broadband performance was in the range of few kHz (depending on the size of the printed sensor). The promising results support future applications of smart 3D-printed systems with embedded sensory elements being used for dynamic measurements in areas where currently piezo-crystal-based sensors are used.
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Arai, Yoshikazu, Atsushi Shibuya, Y. Yoshikawa, and Wei Gao. "Online Measurement of Micro-Aspheric Surface Profile with Compensation of Scanning Error." Key Engineering Materials 381-382 (June 2008): 175–78. http://dx.doi.org/10.4028/www.scientific.net/kem.381-382.175.
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A novel scanning probe measurement system has been developed to achieve precise profile measurements of micro-aspheric surfaces. The system consists of a scanning stage (a spindle and a linear slide) and a sensor unit. The sensor unit consists of a ring artifact, two capacitance sensors and a contact-mode displacement sensor. The two capacitance sensors scan the surface of the ring artifact to measure and compensate the error motions of the scanning stage while the contact-mode displacement sensor scans the surface of a micro-aspheric. In this paper, a new contact-mode displacement sensor that has a small contact force of less than 2.3 mN and a stable output has been developed. After investigating the fundamental performance of the contact-mode displacement sensor, the sensor has been applied to the micro-aspheric surface profile measurement system. The effectiveness of the measurement system has been verified by the measurement results.
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Sui, Ruixiu, Horace C. Pringle, and Edward M. Barnes. "Soil Moisture Sensor Test with Mississippi Delta Soils." Transactions of the ASABE 62, no. 2 (2019): 363–70. http://dx.doi.org/10.13031/trans.12886.
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Abstract. One of the methods for irrigation scheduling is to use sensors to measure the soil moisture level in the plant root zone and apply water if there is a water shortage for the plants. The measurement accuracy and reliability of the soil moisture sensors are critical for sensor-based irrigation management. This study evaluated the measurement accuracy and repeatability of the EC-5 and 5TM soil volumetric water content (SVWC) sensors, the MPS-2 and 200SS soil water potential (SWP) sensors, and the 200TS soil temperature sensor. Six 183 cm × 183 cm × 71 cm wooden compartments were built inside a greenhouse, and each compartment was filled with one type of soil from the Mississippi Delta. A total of 66 sensors with 18 data loggers were installed in the soil compartments to measure SVWC, SWP, and soil temperature. Soil samples were periodically collected from the compartments to determine SVWC using the gravimetric method. SVWC measured by the sensors was compared with that determined by the gravimetric method. The SVWC readings from the sensors had a linear regression relationship with the gravimetric SVWC (r2 = 0.82). This relationship was used to calibrate the sensor readings. The SVWC and SWP sensors could detect the general trend of soil moisture changes. However, their measurements varied significantly among the sensors. To obtain accurate absolute soil moisture measurements, the sensors require individual and soil-specific calibration. The 5TM, MPS-2, and 200TS sensors performed well in soil temperature measurement tests. Individual temperature readings from these sensors were very close to the mean of all sensor readings. Keywords: Irrigation, Sensors, Soil types, Soil water content, Soil water potential.
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Gregori, Amedeo, Emidio Di Giampaolo, Alessandro Di Carlofelice, and Chiara Castoro. "Presenting a New Wireless Strain Method for Structural Monitoring: Experimental Validation." Journal of Sensors 2019 (November 3, 2019): 1–12. http://dx.doi.org/10.1155/2019/5370838.
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The structural health monitoring (SHM) of large and complex infrastructures as well as laboratory tests of new structures and materials resorts to strain gauge measurements to check mechanical stress. A wireless measurement of the strain gauge response is desirable in many practical applications to avoid the cost and the difficulty of wiring, particularly in large structures requiring several sensors and in complex objects where the measurement points are difficult to access. In this paper, a wireless strain gauge which is a hybrid between an RFID tag and a usual thin-film resistive strain gauge is experimented. Installation and maintenance problems of the wireless sensor networks are overcome allowing a high level of measurement accuracy, comparable to that of wired strain sensors, together with a long measurement distance. A large set of measurements has been performed using reference specimens and readings in order to validate the sensor and to develop a calibration procedure that makes the sensor suitable for a large number of different applications in civil engineering.
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Wahyuni, Retno Tri, Abdur Rahman Haritsah, Heri Subagiyo, and Edi Rahmanto. "Rancang Bangun Sensor Node untuk Monitoring Parameter Cuaca dan PM2.5 Menggunakan Arduino WiFi." Jurnal Elektro dan Mesin Terapan (ELEMENTER), Vol. 7 No. 2 (2021) (November 30, 2021): 7–17. http://dx.doi.org/10.35143/elementer.v7i2.5162.
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The node sensor for monitoring weather parameters and PM2.5 consists of weather parameter sensors, such as temperature, humidity, sun radiation intensity, rainfall, wind speed and wind direction. In addition, there are air quality parameters contains, namely pm2.5 sensors. Data processing and delivery is carried out by Arduino Uno WiFi which is a microcontroller device that has been integrated with ESP8226 which is a module to connect with WiFi networks. Sensor data is sent from Arduino to the data base server to be displayed on the website. The test results of each sensor compared to BMKG data showed small measurement error results for temperature and rainfall parameters with error percentages of 4.61% and 9.95% respectively. The results of measuring wind speed parameters have a considerable error of 30.03% caused by wind speed measurements carried out at different altitudes to BMKG sensors. Measurements of wind direction show different wind direction frequencies because they do not set the same reference point as the BMKG sensor at the time of the sensor laying. The PM2.5 measurement also showed a considerable measurement error result of 14.7% because the laying of the sensor was not conditioned with standards as in the BMKG sensor so that the particulate sample measured was not the same as the BMKG sensor. For measurement of sun radiation intensity and humidity each has shown a trend that is in accordance with environmental conditions. Data delivery testing also works well because all data stored on the server database is in the correct column on the data base and shows the same results compared to the sample data that the sensor reads manually. Article Details
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Küng, Alain, Benjamin A. Bircher, and Felix Meli. "Low-Cost 2D Index and Straightness Measurement System Based on a CMOS Image Sensor." Sensors 19, no. 24 (December 11, 2019): 5461. http://dx.doi.org/10.3390/s19245461.
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Accurate traceable measurement systems often use laser interferometers for position measurements in one or more dimensions. Since interferometers provide only incremental information, they are often combined with index sensors to provide a stable reference starting point. Straightness measurements are important for machine axis correction and for systems having several degrees of freedom. In this paper, we investigate the accuracy of an optical two-dimensional (2D) index sensor, which can also be used in a straightness measurement system, based on a fiber-coupled, collimated laser beam pointing onto an image sensor. Additionally, the sensor can directly determine a 2D position over a range of a few millimeters. The device is based on a simple and low-cost complementary metal–oxide–semiconductor (CMOS) image sensor chip and provides sub-micrometer accuracy. The system is an interesting alternative to standard techniques and can even be implemented on machines for real-time corrections. This paper presents the developed sensor properties for various applications and introduces a novel error separation method for straightness measurements.
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Kavaz, Ayse Gokcen, and Burak Barutcu. "Fault Detection of Wind Turbine Sensors Using Artificial Neural Networks." Journal of Sensors 2018 (December 19, 2018): 1–11. http://dx.doi.org/10.1155/2018/5628429.
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This paper proposes a method for sensor validation and fault detection in wind turbines. Ensuring validity of sensor measurements is a significant part in overall condition monitoring as sensor faults lead to incorrect results in monitoring a system’s state of health. Although identifying abrupt failures in sensors is relatively straightforward, calibration drifts are more difficult to detect. Therefore, a detection and isolation technique for sensor calibration drifts on the purpose of measurement validation was developed. Temperature sensor measurements from the Supervisory Control and Data Acquisition system of a wind turbine were used for this aim. Low output rate of the measurements and nonlinear characteristics of the system drive the necessity to design an advanced fault detection algorithm. Artificial neural networks were chosen for this purpose considering their high performance in nonlinear environments. The results demonstrate that the proposed method can effectively detect existence of calibration drift and isolate the exact sensor with faulty behaviour.
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Herregodts, Stijn, Patrick De Baets, Jan Victor, and Matthias Verstraete. "Use of Tekscan pressure sensors for measuring contact pressures in the human knee joint." International Journal Sustainable Construction & Design 6, no. 2 (July 7, 2015): 7. http://dx.doi.org/10.21825/scad.v6i2.1123.
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The Tekscan pressure sensor is a common instrument to quantify in vitro tibiofemoral and patellofemoral contact pressures, which helps to understand the impact of surgical intervention such as total knee arthroplasty (TKA). As a result of the non-linear behavior of the sensor, the conditioning, normalization and calibration of the sensor are critical to achieve correct measurements. In this paper, a literature review is presented that provides insight in the correct use of these sensors, resulting in optimal accuracy. To guarantee the repeatability of the measurements, a secure and correct fixation of the sensor in the joint is required. Using the sensor for intra-articular measurements induces several unintended effects, which potentially lower the accuracy of the measurement. First, the uneven surface can result in wrinkling and destruction of the sensor, in turn leading to measurement results that can be corrupted. Second, the presence of shear forces on the sensor can lead to wear of the sensor and reduction in sensitivity with loss of accuracy as a result. Also the fixation method can worsen the accuracy. In literature, a deterioration of the accuracy from 3% under optimal conditions to errors of more than 50% are reported as a result of the aforementioned effects.
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Jahren, Silje Ekroll, Niels Aakvaag, Frode Strisland, Andreas Vogl, Alessandro Liberale, and Anders E. Liverud. "Towards Human Motion Tracking Enhanced by Semi-Continuous Ultrasonic Time-of-Flight Measurements." Sensors 21, no. 7 (March 24, 2021): 2259. http://dx.doi.org/10.3390/s21072259.
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Human motion analysis is a valuable tool for assessing disease progression in persons with conditions such as multiple sclerosis or Parkinson’s disease. Human motion tracking is also used extensively for sporting technique and performance analysis as well as for work life ergonomics evaluations. Wearable inertial sensors (e.g., accelerometers, gyroscopes and/or magnetometers) are frequently employed because they are easy to mount and can be used in real life, out-of-the-lab-settings, as opposed to video-based lab setups. These distributed sensors cannot, however, measure relative distances between sensors, and are also cumbersome when it comes to calibration and drift compensation. In this study, we tested an ultrasonic time-of-flight sensor for measuring relative limb-to-limb distance, and we developed a combined inertial sensor and ultrasonic time-of-flight wearable measurement system. The aim was to investigate if ultrasonic time-of-flight sensors can supplement inertial sensor-based motion tracking by providing relative distances between inertial sensor modules. We found that the ultrasonic time-of-flight measurements reflected expected walking motion patterns. The stride length estimates derived from ultrasonic time-of-flight measurements corresponded well with estimates from validated inertial sensors, indicating that the inclusion of ultrasonic time-of-flight measurements could be a feasible approach for improving inertial sensor-only systems. Our prototype was able to measure both inertial and time-of-flight measurements simultaneously and continuously, but more work is necessary to merge the complementary approaches to provide more accurate and more detailed human motion tracking.
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Mikhailov, Petr, Zhomart Ualiyev, Assem Kabdoldina, Nurzhigit Smailov, Askar Khikmetov, and Feruza Malikova. "Multifunctional fiber-optic sensors for space infrastructure." Eastern-European Journal of Enterprise Technologies 5, no. 5 (113) (October 31, 2021): 80–89. http://dx.doi.org/10.15587/1729-4061.2021.242995.
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Sensors used in rocket and space technology are subject to extreme external influences in terms of temperature, vibration, and shock. Therefore, the choice of the type of sensors is justified precisely by the resistance to such factors, as well as the ability to ensure the temporal and parametric stability of measurements. A new type of sensors – fiber-optic ones – meets these conditions. The basis for the selection and further improvement of such sensors were such requirements as minimum power consumption, high accuracy and stability of measurements, the ability to combine several measurements in one sensor. It is noted that for space infrastructure the factor of the possibility of simultaneous measurement of several parameters with one sensor is one of the important quality indicators. This is due to the possibility of reducing the number of sensors themselves, which reduces the mass and size parameters of space technology. This applies, first of all, to measurements of pressure and temperature, since they, in aggregate, account for at least 40 % of all measurements in space products. The path of choos-ing the types of methods and sensor designs led to the combination of the amplitude conversion method and optical communication in one sensor. In this case, amplitude modulation of pressure and temperature is carried out by a microelec-tromechanical unit (module), and the modulated optical signal is transmitted by an optical module. Such a modular composition of the sensor makes it possible to dispense with optical ana-lyzers (interrogators) and carry out further pro-cessing based on standard interfaces. A limitation of the proposed methods and designs is the need for microelectromechanical structures that measure certain physical quantities. Such structures for fiber-optic sensors are not mass-produced; therefore, their manufacture can be established at instrument-making enterprises with microelectronic equipment
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SZCZEPAŃSKI, Grzegorz, and Aliaksandra SHMYK. "Testing ToF Sensors for Use in Obstacle Detection Systems." Problems of Mechatronics Armament Aviation Safety Engineering 13, no. 2 (June 30, 2022): 65–74. http://dx.doi.org/10.5604/01.3001.0015.9066.
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ToF (Time of Flight) sensors have been gaining popularity in recent times as a cheap and accurate way to take distance measurements. They may prove to be a key component of obstacle detection systems in the near future. This paper presents a stepper motor system with two measurement modules containing ToF sensors. The results of distance measurements made with these modules relative to a flat surface for different sensor modes are presented. Standard deviations were determined for the measurement results and a polynomial fitting was performed using the linear least squares method. The results were used to select the sensor for further work in terms of its use in an obstacle detection system.
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de Souza, Romina, Claudia Buchhart, Kurt Heil, Jürgen Plass, Francisco M. Padilla, and Urs Schmidhalter. "Effect of Time of Day and Sky Conditions on Different Vegetation Indices Calculated from Active and Passive Sensors and Images Taken from UAV." Remote Sensing 13, no. 9 (April 27, 2021): 1691. http://dx.doi.org/10.3390/rs13091691.
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Optical sensors have been widely reported to be useful tools to assess biomass, nutrition, and water status in several crops. However, the use of these sensors could be affected by the time of day and sky conditions. This study aimed to evaluate the effect of time of day and sky conditions (sunny versus overcast) on several vegetation indices (VI) calculated from two active sensors (the Crop Circle ACS-470 and Greenseeker RT100), two passive sensors (the hyperspectral bidirectional passive spectrometer and HandySpec Field sensor), and images taken from an unmanned aerial vehicle (UAV). The experimental work was conducted in a wheat crop in south-west Germany, with eight nitrogen (N) application treatments. Optical sensor measurements were made throughout the vegetative growth period on different dates in 2019 at 9:00, 14:00, and 16:00 solar time to evaluate the effect of time of day, and on a sunny and overcast day only at 9:00 h to evaluate the influence of sky conditions on different vegetation indices. For most vegetation indices evaluated, there were significant differences between paired time measurements, regardless of the sensor and day of measurement. The smallest differences between measurement times were found between measurements at 14:00 and 16:00 h, and they were observed for the vehicle-carried and the handheld hyperspectral passive sensor being lower than 2% and 4%, respectively, for the indices NIR/Red edge ratio, Red edge inflection point (REIP), and the water index. Differences were lower than 5% for the vehicle-carried active sensors Crop Circle ACS-470 (indices NIR/Red edge and NIR/Red ratios, and NDVI) and Greenseeker RT100 (index NDVI). The most stable indices over measurement times were the NIR/Red edge ratio, water index, and REIP index, regardless of the sensor used. The most considerable differences between measurement times were found for the simple ratios NIR/Red and NIR/Green. For measurements made on a sunny and overcast day, the most stable were the indices NIR/Red edge ratio, water index, and REIP. In practical terms, these results confirm that passive and active sensors could be used to measure on-farm at any time of day from 9:00 to 16:00 h by choosing optimized indices.
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Gao, Song, Min Gao, and Qin Kun Xiao. "Multisensor Tracking of a Maneuvering Target in Clutter with Proposed Parallel Updating Approach." Advanced Materials Research 383-390 (November 2011): 344–51. http://dx.doi.org/10.4028/www.scientific.net/amr.383-390.344.
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To solve the problem of measurement original uncertainty, we present a proposed parallel updating approach for tracking a maneuvering target in cluttered environment using multiple sensors. A parallel updating method is followed where the raw sensor measurements are passed to a central processor and fed directly to the target tracker. A past approach using parallel sensor processing has ignored certain data association probabilities. Simulation results show that compared with an existing IMMPDAF algorithm with parallel sensor approach, the IMMPDAF algorithm with proposed parallel updating approach solves the problem of measurements' origins and achieves significant improvement in the accuracy of track estimation.
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Marković, Marko, Jovan Bajić, Mehmed Batilović, Zoran Sušić, Ana Joža, and Goran Stojanović. "Comparative Analysis of Deformation Determination by Applying Fiber-optic 2D Deflection Sensors and Geodetic Measurements." Sensors 19, no. 4 (February 18, 2019): 844. http://dx.doi.org/10.3390/s19040844.
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In the paper the description of an experiment for a comparative analysis of two different methods for deformation determination, geodetic and 2D deflection sensors based on fiber-optic curvature sensors (FOCSs) is given. The experiment is performed by a using specially designed assembly which makes it possible to apply both methods. For performing geodetic measurements, a geodetic micro-network is established. Measurements by applying a 2D deflection sensor and three total stations are carried out for comparison. The data processing comprises graphical and numerical analysis of the results. Based on the presented results the potential of 2D deflection sensor application in structural health monitoring (SHM) procedures is indicated. The analysis of the measurement results also indicates the importance of integrating various types of sensors for obtaining more accurate and more reliable deformation measurements results.
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Bílek, Jiří, Petr Maršolek, Ondřej Bílek, and Pavel Buček. "Field Test of Mini Photoionization Detector-Based Sensors—Monitoring of Volatile Organic Pollutants in Ambient Air." Environments 9, no. 4 (April 10, 2022): 49. http://dx.doi.org/10.3390/environments9040049.
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The determination of the concentrations of the organic compounds in ambient air using reference methods is a time-consuming process. The samples must be collected on a specific sorbent material and analyzed. In the best-case scenario, the analysis may be performed on site by portable chromatography techniques; otherwise, transport and laboratory analysis is necessary. Continuous sensory measurement is advantageous, especially concerning speed, resolution, price and ease of use. On the other hand, questions are raised, especially on the subject of the quality of data obtained by sensory measurements. The authors tested several types of volatile organic compound (VOC) sensors. The chosen type was deployed in a 25-unit sensor network for further testing by parallel measurements with the reference technique within the CLAIRO project.
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Wang, Kuiwu, Qin Zhang, and Xiaolong Hu. "Improved Distributed Multisensor Fusion Method Based on Generalized Covariance Intersection." Journal of Sensors 2022 (October 28, 2022): 1–22. http://dx.doi.org/10.1155/2022/6348938.
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In response to the multitarget tracking problem of distributed sensors with a limited detection range, a distributed sensor measurement complementary Gaussian component correlation GCI fusion tracking method is proposed on the basis of the probabilistic hypothesis density filtering tracking theory. First, the sensor sensing range is extended by complementing the measurements. In this case, the multitarget density product is used to classify whether the measurements belong to the intersection region of the detection range. The local intersection region is complemented only once to reduce the computational cost. Secondly, each sensor runs a probabilistic hypothesis density filter separately and floods the filtering posterior with the neighboring sensors so that each sensor obtains the posterior information of the neighboring sensors. Subsequently, Gaussian components are correlated by distance division, and Gaussian components corresponding to the same target are correlated into the same subset. GCI fusion is performed on each correlated subset to complete the fusion state estimation. Simulation experiments show that the proposed method can effectively perform multitarget tracking in a distributed sensor network with a limited sensing range.
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Santos, Eduardo Alvarez, Paulo Cesar Sentelhas, Terry James Gillespie, and Jorge Lulu. "Performance of cylindrical leaf wetness duration sensors in a tropical climate condition." Scientia Agricola 65, spe (December 2008): 1–9. http://dx.doi.org/10.1590/s0103-90162008000700003.
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Leaf wetness duration (LWD) measurements are required for disease warning in several agricultural systems, since it is an important variable for the diagnose of plant disease epidemiology. The cylindrical sensor is an inexpensive and simple electronic LWD sensor initially designed to measure this variable for onions, however some studies show that it may be helpful for standard measurements in weather stations and also for different crops. Therefore, the objective of this study was to assess their performance under tropical climate conditions, in Brazil, having as standard measurements those obtained by flat plate sensors, which have presented very good performance when compared with visual observations. Before field assessments, all LWD sensors used in our study (flat plates and cylinders) were white latex painted and submitted to a heat treatment. Laboratory tests were performed in order to determine the resistance threshold for the sensor to be considered wet and the time response of the sensors to wetness. In the field, all cylindrical sensors were initially deployed horizontally 30-cm above a turfgrass surface in order to assess the variability among them with respect to LWD measurements. The variability among the horizontal cylindrical sensors was reduced by using a specific resistance threshold for each sensor. The mean coefficient of variation (CV) of LWD data measured by the cylindrical sensors was 9.7%. After that, the cylindrical sensors were deployed at five different angles: 0º, 15º, 30º, 45º, and 60º. Data of measurements made at these angles were compared with the standard measurement, obtained by flat plate sensors at the same height and installed at 45º. The deployment angle had no systematic effect on LWD measurements for the local tropical conditions, since the correlations between flat plate and elevated cylinder measurements were very high (R² > 0.91), which differed from the results obtained under temperate climatic conditions, where LWD measured by cylinders were two hours longer than by flat plate sensors.
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Unang Achlison. "Analisis Implementasi Pengukuran Suhu Tubuh Manusia dalam Pandemi Covid-19 di Indonesia." Pixel :Jurnal Ilmiah Komputer Grafis 13, no. 2 (December 24, 2020): 102–6. http://dx.doi.org/10.51903/pixel.v13i2.318.
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The corona virus (Covid-19) has attacked almost the entire world, including Indonesia. Places where community activities must comply with health protocols, one of which is checking human body temperature. The measurement of human body sensors is a very significant difference even though it is applied to the same human body, this is due to several factors. This research analyzes the measurement results of the human body temperature sensor. This study aims to determine an effective and efficient human body temperature sensor. The process of measuring human body temperature uses a microcontroller-based temperature sensor. After the results of temperature measurements using different temperature sensors are obtained, the measurement results are analyzed and compared to obtain an effective and efficient temperature sensor. Based on the analysis, the results of measuring human body temperature using a thermal camera are an effective and efficient sensor.
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Thomas, Rick M., A. Rob MacKenzie, S. James Reynolds, Jonathan P. Sadler, Ford Cropley, Simon Bell, Stephen J. Dugdale, Lee Chapman, Andrew Quinn, and Xiaoming Cai. "Avian Sensor Packages for Meteorological Measurements." Bulletin of the American Meteorological Society 99, no. 3 (March 1, 2018): 499–511. http://dx.doi.org/10.1175/bams-d-16-0181.1.
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Abstract The increasing miniaturization of accurate, reliable meteorological sensors and logging systems allows the deployment of sensor packages on lightweight airborne platforms. Here, we demonstrate the safe and humane use of avian species (white-tailed and Spanish imperial eagles) to carry a prototype miniature sensor package to measure temperature with a 5-Hz response and ±0.2°C resolution. This technique could allow sensor deployment above complex urban terrain, where such data are urgently required. Recent meteorological work has been facilitated by using unmanned aerial vehicles (UAVs), but their use within, and adjacent to, urban areas is heavily controlled. The package contains a wind speed sensor, a GPS, a pressure altimeter, and accelerometers. Four flight tests were conducted in a steep valley (glen) at a remote Scottish location that provided contrasting vertical temperature profiles. The glen was instrumented with additional meteorological equipment at the bird launch and landing sites. Vertical temperature profile data from the raptors indicated the success of this approach with absolute temperatures and lapse rates consistent with those measured by the weather stations. Movement and airspeed data aided the interpretation of finescale temperature profiles in complex terrain. As well as the potential for meteorological sensing, this work is of interest to the avian ecology and behavior communities and to aerodynamicists interested in developing airborne robotics to mimic aspects of bird flight. These sensors are being miniaturized further for deployment on other bird species in urban areas for rapid, repeatable, and reliable measurements, with the potential to fulfill a measurement niche above the urban canopy.
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Barbieri, Lindsay, Stephan Kral, Sean Bailey, Amy Frazier, Jamey Jacob, Joachim Reuder, David Brus, et al. "Intercomparison of Small Unmanned Aircraft System (sUAS) Measurements for Atmospheric Science during the LAPSE-RATE Campaign." Sensors 19, no. 9 (May 10, 2019): 2179. http://dx.doi.org/10.3390/s19092179.
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Small unmanned aircraft systems (sUAS) are rapidly transforming atmospheric research. With the advancement of the development and application of these systems, improving knowledge of best practices for accurate measurement is critical for achieving scientific goals. We present results from an intercomparison of atmospheric measurement data from the Lower Atmospheric Process Studies at Elevation—a Remotely piloted Aircraft Team Experiment (LAPSE-RATE) field campaign. We evaluate a total of 38 individual sUAS with 23 unique sensor and platform configurations using a meteorological tower for reference measurements. We assess precision, bias, and time response of sUAS measurements of temperature, humidity, pressure, wind speed, and wind direction. Most sUAS measurements show broad agreement with the reference, particularly temperature and wind speed, with mean value differences of 1.6 ± 2.6 ∘ C and 0.22 ± 0.59 m/s for all sUAS, respectively. sUAS platform and sensor configurations were found to contribute significantly to measurement accuracy. Sensor configurations, which included proper aspiration and radiation shielding of sensors, were found to provide the most accurate thermodynamic measurements (temperature and relative humidity), whereas sonic anemometers on multirotor platforms provided the most accurate wind measurements (horizontal speed and direction). We contribute both a characterization and assessment of sUAS for measuring atmospheric parameters, and identify important challenges and opportunities for improving scientific measurements with sUAS.
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Levy, Daniel, Jason Roos, Jace Robinson, William Carpenter, Richard Martin, Clark Taylor, Joseph Sugrue, and Andrew Terzuoli. "NON LINEAR OPTIMIZATION APPLIED TO ANGLE-OF-ARRIVAL SATELLITE BASED GEO-LOCALIZATION FOR BIASED AND TIME-DRIFTING SENSORS." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLI-B2 (June 7, 2016): 319–25. http://dx.doi.org/10.5194/isprs-archives-xli-b2-319-2016.
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Multiple sensors are used in a variety of geolocation systems. Many use Time Difference of Arrival (TDOA) or Received Signal Strength (RSS) measurements to estimate the most likely location of a signal. When an object does not emit an RF signal, Angle of Arrival (AOA) measurements using optical or infrared frequencies become more feasible than TDOA or RSS measurements. AOA measurements can be created from any sensor platform with any sort of optical sensor, location and attitude knowledge to track passive objects. Previous work has created a non-linear optimization (NLO) method for calculating the most likely estimate from AOA measurements. Two new modifications to the NLO algorithm are created and shown to correct AOA measurement errors by estimating the inherent bias and time-drift in the Inertial Measurement Unit (IMU) of the AOA sensing platform. One method corrects the sensor bias in post processing while treating the NLO method as a module. The other method directly corrects the sensor bias within the NLO algorithm by incorporating the bias parameters as a state vector in the estimation process. These two methods are analyzed using various Monte-Carlo simulations to check the general performance of the two modifications in comparison to the original NLO algorithm.
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Levy, Daniel, Jason Roos, Jace Robinson, William Carpenter, Richard Martin, Clark Taylor, Joseph Sugrue, and Andrew Terzuoli. "NON LINEAR OPTIMIZATION APPLIED TO ANGLE-OF-ARRIVAL SATELLITE BASED GEO-LOCALIZATION FOR BIASED AND TIME-DRIFTING SENSORS." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLI-B2 (June 7, 2016): 319–25. http://dx.doi.org/10.5194/isprsarchives-xli-b2-319-2016.
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Multiple sensors are used in a variety of geolocation systems. Many use Time Difference of Arrival (TDOA) or Received Signal Strength (RSS) measurements to estimate the most likely location of a signal. When an object does not emit an RF signal, Angle of Arrival (AOA) measurements using optical or infrared frequencies become more feasible than TDOA or RSS measurements. AOA measurements can be created from any sensor platform with any sort of optical sensor, location and attitude knowledge to track passive objects. Previous work has created a non-linear optimization (NLO) method for calculating the most likely estimate from AOA measurements. Two new modifications to the NLO algorithm are created and shown to correct AOA measurement errors by estimating the inherent bias and time-drift in the Inertial Measurement Unit (IMU) of the AOA sensing platform. One method corrects the sensor bias in post processing while treating the NLO method as a module. The other method directly corrects the sensor bias within the NLO algorithm by incorporating the bias parameters as a state vector in the estimation process. These two methods are analyzed using various Monte-Carlo simulations to check the general performance of the two modifications in comparison to the original NLO algorithm.
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Yuan, Dandan, Wenjun Yi, and Jun Guan. "Roll Attitude Determination of Spin Projectile Based on GPS and Magnetoresistive Sensor." Mathematical Problems in Engineering 2017 (2017): 1–9. http://dx.doi.org/10.1155/2017/9638741.
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Improvement in attack accuracy of the spin projectiles is a very significant objective, which increases the overall combat efficiency of projectiles. The accurate determination of the projectile roll attitude is the recent objective of the efficient guidance and control. The roll measurement system for the spin projectile is commonly based on the magnetoresistive sensor. It is well known that the magnetoresistive sensor produces a sinusoidally oscillating signal whose frequency slowly decays with time, besides the possibility of blind spot. On the other hand, absolute sensors such as GPS have fixed errors even though the update rates are generally low. To earn the benefit while eliminating weaknesses from both types of sensors, a mathematical model using filtering technique can be designed to integrate the magnetoresistive sensor and GPS measurements. In this paper, a mathematical model is developed to integrate the magnetoresistive sensor and GPS measurements in order to get an accurate prediction of projectile roll attitude in a real flight time. The proposed model is verified using numerical simulations, which illustrated that the accuracy of the roll attitude measurement is improved.
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Mukherjee, Anondo, Steven G. Brown, Michael C. McCarthy, Nathan R. Pavlovic, Levi G. Stanton, Janice Lam Snyder, Stephen D’Andrea, and Hilary R. Hafner. "Measuring Spatial and Temporal PM2.5 Variations in Sacramento, California, Communities Using a Network of Low-Cost Sensors." Sensors 19, no. 21 (October 29, 2019): 4701. http://dx.doi.org/10.3390/s19214701.
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Low-cost sensors can provide insight on the spatio-temporal variability of air pollution, provided that sufficient efforts are made to ensure data quality. Here, 19 AirBeam particulate matter (PM) sensors were deployed from December 2016 to January 2017 to determine the spatial variability of PM2.5 in Sacramento, California. Prior to, and after, the study, the 19 sensors were deployed and collocated at a regulatory air monitoring site. The sensors demonstrated a high degree of precision during all collocated measurement periods (Pearson R2 = 0.98 − 0.99 across all sensors), with little drift. A sensor-specific correction factor was developed such that each sensor reported a comparable value. Sensors had a moderate degree of correlation with regulatory monitors during the study (R2 = 0.60 − 0.68 at two sites). In a multi-linear regression model, the deviation between sensor and reference measurements of PM2.5 had the highest correlation with dew point and relative humidity. Sensor measurements were used to estimate the PM2.5 spatial variability, finding an average pairwise coefficient of divergence of 0.22 and a range of 0.14 to 0.33, indicating mostly homogeneous distributions. No significant difference in the average sensor PM concentrations between environmental justice (EJ) and non-EJ communities (p value = 0.24) was observed.
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Bogucki, Darek J., Tom Snowdon, Jennifer C. Doerr, and Joseph E. Serafy. "A Salinity–Temperature Sensor Based on Microwave Resonance Reflection." Sensors 22, no. 15 (August 8, 2022): 5915. http://dx.doi.org/10.3390/s22155915.
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We developed and tested a microwave in situ salinity sensor (MiSSo) to simultaneously measure salinity and temperature within the same water sample over broad ranges of salinity (S) (3–50 psu) and temperature (T) (3–30 °C). Modern aquatic S sensors rely on measurements of conductivity (C) between a set of electrodes contained within a small volume of water. To determine water salt content or S, conductivity, or C, measurements must be augmented with concurrent T measurements from the same water volume. In practice, modern S sensors do not sample C and T within the same volume, resulting in the S determination characterized by measurement artifacts. These artifacts render processing vast amounts of available C and T data to derive S time-consuming and generally preclude automated processing. Our MiSSo approach eliminates the need for an additional T sensor, as it permits us to concurrently determine the sample S and T within the same water volume. Laboratory trials demonstrated the MiSSo accuracy of S and T measurements to be <0.1 psu and <0.1 °C, respectively, when using microwave reflections at 11 distinct frequencies. Each measurement took 0.1 μs. Our results demonstrate a new physical method that permits the accurate S and T determination within the same water volume.
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Cross, Eben S., Leah R. Williams, David K. Lewis, Gregory R. Magoon, Timothy B. Onasch, Michael L. Kaminsky, Douglas R. Worsnop, and John T. Jayne. "Use of electrochemical sensors for measurement of air pollution: correcting interference response and validating measurements." Atmospheric Measurement Techniques 10, no. 9 (September 29, 2017): 3575–88. http://dx.doi.org/10.5194/amt-10-3575-2017.
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Abstract. The environments in which we live, work, and play are subject to enormous variability in air pollutant concentrations. To adequately characterize air quality (AQ), measurements must be fast (real time), scalable, and reliable (with known accuracy, precision, and stability over time). Lower-cost air-quality-sensor technologies offer new opportunities for fast and distributed measurements, but a persistent characterization gap remains when it comes to evaluating sensor performance under realistic environmental sampling conditions. This limits our ability to inform the public about pollution sources and inspire policy makers to address environmental justice issues related to air quality. In this paper, initial results obtained with a recently developed lower-cost air-quality-sensor system are reported. In this project, data were acquired with the ARISense integrated sensor package over a 4.5-month time interval during which the sensor system was co-located with a state-operated (Massachusetts, USA) air quality monitoring station equipped with reference instrumentation measuring the same pollutant species. This paper focuses on validating electrochemical (EC) sensor measurements of CO, NO, NO2, and O3 at an urban neighborhood site with pollutant concentration ranges (parts per billion by volume, ppb; 5 min averages, ±1σ): [CO] = 231 ± 116 ppb (spanning 84–1706 ppb), [NO] = 6.1 ± 11.5 ppb (spanning 0–209 ppb), [NO2] = 11.7 ± 8.3 ppb (spanning 0–71 ppb), and [O3] = 23.2 ± 12.5 ppb (spanning 0–99 ppb). Through the use of high-dimensional model representation (HDMR), we show that interference effects derived from the variable ambient gas concentration mix and changing environmental conditions over three seasons (sensor flow-cell temperature = 23.4 ± 8.5 °C, spanning 4.1 to 45.2 °C; and relative humidity = 50.1 ± 15.3 %, spanning 9.8–79.9 %) can be effectively modeled for the Alphasense CO-B4, NO-B4, NO2-B43F, and Ox-B421 sensors, yielding (5 min average) root mean square errors (RMSE) of 39.2, 4.52, 4.56, and 9.71 ppb, respectively. Our results substantiate the potential for distributed air pollution measurements that could be enabled with these sensors.
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Alqurashi, Yousef, Mohamed Elsherif, Asail Hendi, Khamis Essa, and Haider Butt. "Optical Hydrogel Detector for pH Measurements." Biosensors 12, no. 1 (January 13, 2022): 40. http://dx.doi.org/10.3390/bios12010040.
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Measuring pH has become a major key for determining health conditions, and food safety. The traditional pH assessment approaches are costly and offer low sensitivity. Here, a novel pH sensor based on a pH-responsive hydrogel has been developed. A Fresnel lens pattern was replicated on the surface of the pH-responsive hydrogel using the replica mould method. The pH sensors were tested in a pH range of 4–7. Introducing various pH solutions to the pH sensor led to volumetric shifts as the hydrogel swelled with pH. Consequently, the dimensions of the replicated Fresnel lens changed, modifying the focal length and the focus efficiency of the optical sensor. As a result, the measured optical power at a fixed distance from the sensor changed with pH. The optical sensor showed the best performance in the acidic region when pH changed from 4.5 to 5.5, in which the recorded power increased by 13%. The sensor exhibited high sensitivity to pH changes with a short respond time in a reversible manner. The developed pH optical sensor may have applications in medical point-of-care diagnostics and wearable continuous pH detection devices.
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van Putten, M. J. A. M., C. R. Kleijn, and H. E. A. van den Akker. "Multi-Parameter Sensing With a Thermal Silicon Flow Sensor." Journal of Fluids Engineering 124, no. 3 (August 19, 2002): 643–49. http://dx.doi.org/10.1115/1.1486471.
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We present a method for multi-parameter sensing in the application of thermal vector flow sensors. The method is based on the property that two independent signals can be obtained from a single sensing element, viz. a thermal vector flow sensor. For particular applications, this reduces the number of sensors in the measurement process. It may also allow redundant measurement of physical parameters, such as temperature; these redundant measurements are important for self-diagnostics of proper operation of a measurement system. The method is applied to a bidirectional silicon flow sensor, that generates two independent signals, both being a function of the Re number and the fluid temperature. This allows both temperature and mass flow measurement by use of a single sensor. Temperature estimates are accurate within 0.64 K and mass flow estimates within 5.6%.
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Wang, Tao, Bicong Wang, Yufeng Luo, Hengyu Li, Jinjun Rao, Zhizheng Wu, and Mei Liu. "Accurate Measurements of the Rotational Velocities of Brushless Direct-Current Motors by Using an Ultrasensitive Magnetoimpedance Sensing System." Micromachines 10, no. 12 (December 6, 2019): 859. http://dx.doi.org/10.3390/mi10120859.
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Reports on measurements of the rotational velocity by using giant magnetoimpedance (GMI) sensors are rarely seen. In this study, a rotational-velocity sensing system based on GMI effect was established to measure rotational velocities of brushless direct-current motors. Square waves and sawtooth waves were observed due to the rotation of the shaft. We also found that the square waves gradually became sawtooth waves with increasing the measurement distance and rotational velocity. The GMI-based rotational-velocity measurement results (1000–4300 r/min) were further confirmed using the Hall sensor. This GMI sensor is capable of measuring ultrahigh rotational velocity of 84,000 r/min with a large voltage response of 5 V, even when setting a large measurement distance of 9 cm. Accordingly, the GMI sensor is very useful for sensitive measurements of high rotational velocity.
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Yun, Zhong, Kuibing Li, Hao Jiang, and Xiaoyan Tang. "A Composite Flexible Sensor for Direct Ventricular Assist Device." Sensors 22, no. 7 (March 29, 2022): 2607. http://dx.doi.org/10.3390/s22072607.
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A direct ventricular assist device is one of the effective means to treat patients with heart failure; the key point of the problem is the flexible sensor that can measure the drive pressure and shape variable of the heart auxiliary device. This study was based on the high-voltage electric field guidance process and the porous foaming process, and designed an implantable resistance/capacitive composite flexible sensor that can effectively detect the pressure and deformation signal caused by fine surface contact and pneumatic muscle expansion. Experiments showed the performance of composite sensors with special structure design was greatly improved compared with the control group—the strain measurement sensitivity was 22, pressure measurement sensitivity was up to 0.19 Kpa−1. Stable strain measurements were made up to 35 times and pressure measurements over 100 times. In addition, we solved the interference problem of resistance/capacitance flexible sensors through an optimized common substrate process. Finally, we tested a pneumatic muscle direct ventricular assist device with a composite flexible sensor on a model heart; the experiment showed that this resistance/capacitive composite flexible sensor can effectively detect surface contact with pneumatic muscle and the displacement signals.
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SCHLEICHERT, JAN, ILKO RAHNEBERG, and THOMAS FRÖHLICH. "CALIBRATION OF A NOVEL SIX-DEGREE-OF-FREEDOM FORCE/TORQUE MEASUREMENT SYSTEM." International Journal of Modern Physics: Conference Series 24 (January 2013): 1360017. http://dx.doi.org/10.1142/s2010194513600173.
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Multi-component force/torque transducers are used in a large field of scientific and industrial applications like robotics, biomechanics and even fluid mechanics. These sensors need to be calibrated for traceable measurements. As the calibration procedure determines the measurement uncertainty, it plays an important role in sensor development for reaching the required measurement specifications. For the application in local Lorentz Force Velocimetry (Ref. 1) a six degree of freedom force/torque sensor for measurement ranges of ± 0.2 N and ± 5 mNm was developed. This sensor can also be adapted to other applications that require multi-dimensional force/torque feedback in the μN- and μNm-range such as tactile dimensional measurements and micro-manipulation. This paper discusses the calibration and the evaluation of the properties of the calibration device and the calibration procedure of the sensor system. After a brief introduction of the sensor design and its working principle the calibration setup is described and the uncertainty contributions to the forces and torques are calculated. Then the calibration procedure is presented and the resulting output signals of the sensor are depicted. As a result of the calibration, the calibration matrix is given with a discussion of its major components.
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Sugawara, Tsutomu, Hiroshi Matsumoto, Hiroki Ito, Shingo Sato, and Masanari Kokubu. "Co-fired Platinum High Temperature Sensor Element." Additional Conferences (Device Packaging, HiTEC, HiTEN, and CICMT) 2016, HiTEC (January 1, 2016): 000056–60. http://dx.doi.org/10.4071/2016-hitec-56.
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Abstract In recent years, initiatives for improving the fuel consumptions have been accelerated to reduce the CO2 emissions in exhaust gas from an automotive engine; as a measure against global warming. One of the known techniques to reduce CO2 emissions, is more accurate temperature measurement of the engine. For such application, sensors such as thermistors or thin-film platinum temperature sensors have been widely used for sensing exhaust gas temperature. Especially, the thin-film platinum temperature sensors were favorable because of its linearity in resistance to temperature dependensy and accuracy in temperature measurements. However, the deformation of a resistor circuit in thin-film platinum temperature sensor elements have been observed after used in high temperature. The deformation causes the resistance drifts which leads to less accurate temperature measurements. In this study, durability of the co-fired platinum temperature sensor element was examined for high temperature application. As of result, we found that the resistance drift of the co-fired platinum temperature sensor elements were smaller than that of the thin-film platinum temperature sensor elements; after storage test at 1100 °C. Thus, the co-fired platinum temperature sensor elements can be used for higher temperature sensing, which can contribute to the reduction of CO2 emission of automotive engines.
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Mahabbat Khudaverdieva, Mahabbat Khudaverdieva. "DISTANCE MEASURING BY ULTRASONIC SENSOR." Caucasus-Economic and Social Analysis Journal of Southern Caucasus 49, no. 02 (June 1, 2022): 36–43. http://dx.doi.org/10.36962/cesajsc49022022-36.
Full textAbstract:
The paper is devoted to checking the accuracy of the ultrasonic sensor measuring distance in the current configuration. SFR08 type equipped with I2C communication interface, which allows addressing, was selected as a measurement sensor. This fact makes it easy to create a sensor matrix. Because the communication card is used as a NI USB 8451, the control and visualization system is available as a PC (PC) based system. The purpose of verification measurements is to determine the actual sensor accuracy, especially when measuring longer distances. When measuring the accuracy of the sensor, the measured data were not included in the temperature compensation. Keywords: Ultrasonic sensors, I2C communication interface, virtual tool
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Appeltans, Simon, Angela Guerrero, Said Nawar, Jan Pieters, and Abdul M. Mouazen. "Practical Recommendations for Hyperspectral and Thermal Proximal Disease Sensing in Potato and Leek Fields." Remote Sensing 12, no. 12 (June 15, 2020): 1939. http://dx.doi.org/10.3390/rs12121939.
Full textAbstract:
Thermal and hyperspectral proximal disease sensing are valuable tools towards increasing pesticide use efficiency. However, some practical aspects of the implementation of these sensors remain poorly understood. We studied an optimal measurement setup combining both sensors for disease detection in leek and potato. This was achieved by optimising the signal-to-noise ratio (SNR) based on the height of measurement above the crop canopy, off-zenith camera angle and exposure time (ET) of the sensor. Our results indicated a clear increase in SNR with increasing ET for potato. Taking into account practical constraints, the suggested setup for a hyperspectral sensor in our experiment involves (for both leek and potato) an off-zenith angle of 17°, height of 30 cm above crop canopy and ET of 1 ms, which differs from the optimal setup of the same sensor for wheat. Artificial light proved important to counteract the effect of cloud cover on hyperspectral measurements. The interference of these lamps with thermal measurements was minimal for a young leek crop but increased in older leek and after long exposure. These results indicate the importance of optimising the setup before measurements, for each type of crop.
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Whitehill, Andrew R., Russell W. Long, Shawn P. Urbanski, Maribel Colón, Andrew Habel, and Matthew S. Landis. "Evaluation of Cairpol and Aeroqual Air Sensors in Biomass Burning Plumes." Atmosphere 13, no. 6 (May 28, 2022): 877. http://dx.doi.org/10.3390/atmos13060877.
Full textAbstract:
Cairpol and Aeroqual air quality sensors measuring CO, CO2, NO2, and other species were tested on fresh biomass burning plumes in field and laboratory environments. We evaluated the sensors by comparing 1 min sensor measurements to collocated reference instrument measurements. The sensors were evaluated based on the coefficient of determination (r2) between the sensor and reference measurements, as well as by the accuracy, collocated precision, root mean square error (RMSE), and other metrics. In general, CO and CO2 sensors performed well (in terms of accuracy and r2 values) compared to NO2 sensors. Cairpol CO and NO2 sensors had better sensor-versus-sensor agreement (i.e., collocated precision) than Aeroqual CO and NO2 sensors of the same species. Tests of other sensors (e.g., NH3, H2S, VOC, and NMHC) provided more inconsistent results and need further study. Aeroqual NO2 sensors had an apparent O3 interference that was not observed in the Cairpol NO2 sensors. Although the sensor accuracy lags that of reference-level monitors, with location-specific calibrations they have the potential to provide useful data about community air quality and personal exposure to smoke impacts.