Journal articles: 'Sensor CO2'

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Widodo, Slamet, M. Miftakul Amin, and Adi Sutrisman. "The Design of The Monitoring Tools Of Clean Air Condition And Dangerous Gas CO, CO2 CH4 In Chemical Laboratory By Using Fuzzy Logic Based On Microcontroller." E3S Web of Conferences 31 (2018): 10008. http://dx.doi.org/10.1051/e3sconf/20183110008.

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There are many phenomena that human are exposed to toxins from certain types such as of CO2, CO2 and CH4 gases. The device used to detect large amounts of CO, CO2, and CH4 gas in air in enclosed spaces using MQ 135 gas sensors of different types based on the three sensitivity of the Gas. The results of testing the use of sensors MQ 135 on the gas content of CO, CO2 and CH4 received by the sensor is still in the form of ppm based on the maximum ppm detection range of each sensor. Active sensor detects CO 120 ppm gas, CO2 1600 ppm and CH4 1ppm "standby 1" air condition with intermediate rotary fan. Active sensor detects CO 30 ppm gas, CO2 490 ppm and CH4 7 ppm "Standby 2" with low rotating fan output. Fuzzy rulebase logic for motor speed when gas detection sensor CO, CO2, and CH4 output controls the motion speed of the fan blower. Active sensors detect CO 15 ppm, CO2 320 ppm and CH4 45 ppm "Danger" air condition with high fan spin fan. At the gas level of CO 15 ppm, CO2 390 ppm and CH4 3 ppm detect "normal" AC sensor with fan output stop spinning.

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Boudaden, Jamila, Armin Klumpp, Hanns-Erik Endres, and Ignaz Eisele. "Capacitive CO2 Sensor." Proceedings 1, no. 4 (August 11, 2017): 472. http://dx.doi.org/10.3390/proceedings1040472.

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Wang, Guangwei, Hongzhen Chen, and Yuanhui Wu. "Influence of Heat Disturbance on the Performance of YSZ based CO2 Sensor with Compound of Li2CO3-BaCO3-Nd2O3 as Auxiliary Sensing Electrode." Journal of New Materials for Electrochemical Systems 23, no. 4 (December 31, 2020): 244–51. http://dx.doi.org/10.14447/jnmes.v23i4.a04.

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Suddenly changes and fluctuations of temperature often occur in the operational environment of the CO2 electrochemical sensor. In this work, the YSZ based potentiometric CO2 sensor having Li2CO3-BaCO3-Nd2O3 compound as its auxiliary sensing material was prepared. And the effects of several types of heat disturbance on the performance of this kind of sensor ware studied. The results indicate that the sensors after heat disturbances respond similarly with the sensor as prepared, which presents rapid and correct response for the change of CO2 concentration within the experimental range of 271-576802 ppm. The sensors, with or without heat disturbance, respond well as different extents of abrupt alteration of CO2 concentration occurs, and the EMF outputs recover rapidly as the concentration of CO2 change back to the base value. At the constant concentration of CO2, the EMFs of the sensors with or without heat treatment decrease slowly as the time increases, the reason for this phenomenon might be the accumulation of inert substances on the electrode interfaces and ageing of electrodes. However, heat treatment can improve the long-term stability of the sensor to some extent. Furthermore, this type of sensor works stably with the existence of water vapor (10%), it has similar response curve in the dry and water vapor content system. After some further investigations and improvements, it might be potentially applied in the practical combustion atmosphere.

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Müller, Michael, Peter Graf, Jonas Meyer, Anastasia Pentina, Dominik Brunner, Fernando Perez-Cruz, Christoph Hüglin, and Lukas Emmenegger. "Integration and calibration of non-dispersive infrared (NDIR) CO2 low-cost sensors and their operation in a sensor network covering Switzerland." Atmospheric Measurement Techniques 13, no. 7 (July 15, 2020): 3815–34. http://dx.doi.org/10.5194/amt-13-3815-2020.

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Abstract. More than 300 non-dispersive infrared (NDIR) CO2 low-cost sensors labelled as LP8 were integrated into sensor units and evaluated for the purpose of long-term operation in the Carbosense CO2 sensor network in Switzerland. Prior to deployment, all sensors were calibrated in a pressure and climate chamber and in ambient conditions co-located with a reference instrument. To investigate their long-term performance and to test different data processing strategies, 18 sensors were deployed at five locations equipped with a reference instrument after calibration. Their accuracy during 19 to 25 months deployment was between 8 and 12 ppm. This level of accuracy requires careful sensor calibration prior to deployment, continuous monitoring of the sensors, efficient data filtering, and a procedure to correct drifts and jumps in the sensor signal during operation. High relative humidity (> ∼85 %) impairs the LP8 measurements, and corresponding data filtering results in a significant loss during humid conditions. The LP8 sensors are not suitable for the detection of small regional gradients and long-term trends. However, with careful data processing, the sensors are able to resolve CO2 changes and differences with a magnitude larger than about 30 ppm. Thereby, the sensor can resolve the site-specific CO2 signal at most locations in Switzerland. A low-power network (LPN) using LoRaWAN allowed for reliable data transmission with low energy consumption and proved to be a key element of the Carbosense low-cost sensor network.

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Handlogten, Mary E., Naoki Shiraishi, Hisataka Awata, Chunfa Huang, and R. Tyler Miller. "Extracellular Ca2+-sensing receptor is a promiscuous divalent cation sensor that responds to lead." American Journal of Physiology-Renal Physiology 279, no. 6 (December 1, 2000): F1083—F1091. http://dx.doi.org/10.1152/ajprenal.2000.279.6.f1083.

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The extracellular Ca2+-sensing receptor (CaR) responds to polycations, including Ca2+ and neomycin. This receptor is a physiological regulator of systemic Ca2+ metabolism and may also mediate the toxic effects of hypercalcemia. A number of divalent cations, including Pb2+, Co2+, Cd2+, and Fe2+, are toxic to the kidney, brain, and other tissues where the CaR is expressed. To determine which divalent cations can activate the CaR, we expressed the human CaR in HEK-293 cells and measured activation of phospholipase A2(PLA2) and the mitogen-activated protein kinase p42ERK in response to potential agonists for the receptor. HEK-293 cells expressing the nonfunctional mutant CaR R796W served as controls. Extracellular Ca2+, Ba2+, Cd2+, Co2+, Fe2+, Gd3+, Ni2+, Pb2+, and neomycin activated the CaR, but Hg2+and Fe3+ did not. We analyzed the kinetics of activation of p42ERK and PLA2 by the CaR in response to Ca2+, Co2+, and Pb2+. The EC50 values ranged from ∼0.1 mM for Pb2+ to ∼4.0 mM for Ca2+. The Hill coefficients were >3, indicating multiple cooperative ligand binding sites or subunits. Submaximal concentrations of Ca2+ and Pb2+ were additive for activation of the CaR. The EC50 for Ca2+ or Pb2+ was reduced four- to fivefold by the presence of the other ion. These divalent cations also activated PLA2 via the CaR in Madin-Darby canine kidney cells that stably express the CaR. We conclude that many divalent cations activate the CaR and that their effects are additive. The facts that the CaR is a promiscuous polycation sensor and that the effects of these ions are additive to activate it suggest that the CaR may contribute to the toxicity of some heavy metals such as Pb2+, Cd2+, Co2+, and Fe2+ for the kidney and other tissues where it is expressed.

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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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Yang, Lung Jieh. "Gas Permeation in Polydimethylsiloxane In Situ Monitoring by Silicon Pressure Sensors." Advanced Materials Research 74 (June 2009): 113–16. http://dx.doi.org/10.4028/www.scientific.net/amr.74.113.

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This paper proposes a new way to detect the gas-leakage through PDMS. We use PDMS instead of Pyrex #7740 glass to seal the backside V-grooves of silicon pressure sensors. We put the packaged sensor into a pressurized chamber with CO2 at 300 psi. By observing the output voltage of the pressure sensor, the time history for CO2 permeating into the sensor cavity was easily found. In experiments, we use several PDMS membranes with different thickness, from 45 to 2000 μm, to package the pressure sensors and investigate the gas-leakage of PDMS. The gas leaking through PDMS is shown to be governed by diffusion mechanism, and the diffusion coefficients derived from CO2 leaking history is 2.2×10-9 m2/sec, matched with the previous work.

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Ming, An Jie, Yao Hui Ren, Yu Zhang, Le Zhang, Wen Bo Zhang, Zhen Xin Tan, Wen Ou, et al. "A Compact Infrared Gas Sensor Based on an Asymmetry Gas Cavity." Key Engineering Materials 645-646 (May 2015): 1111–14. http://dx.doi.org/10.4028/www.scientific.net/kem.645-646.1111.

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Many gas molecules absorb electromagnetic radiation at characteristic wavelengths in the infrared region. This absorption can be used to identify defined substances like CO2, ammoniac, and so far. This study presents a comparative analysis of parameters of infrared radiation source and detector hardware that are most important for the creation of portable optical nondispersive infrared (NDIR) gas sensors. One of the central issues in the design of this kind of sensors is the geometry of the sensor cell. In this paper we investigate an asymmetry sensor cavity and predict the performance using Tracepro software. Then, the CO2 sensor is made and tested.

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Santonico, Marco, Alessandro Zompanti, Anna Sabatini, Luca Vollero, Simone Grasso, Carlo Di Mezza, and Giorgio Pennazza. "CO2 and O2 Detection by Electric Field Sensors." Sensors 20, no. 3 (January 25, 2020): 668. http://dx.doi.org/10.3390/s20030668.

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In this work an array of chemical sensors for gas detection has been developed, starting with a commercial sensor platform developed by Microchip (GestIC), which is normally used to detect, trace, and classify hand movements in space. The system is based on electric field changes, and in this work, it has been used as mechanism revealing the adsorption of chemical species CO2 and O2. The system is composed of five electrodes, and their responses were obtained by interfacing the sensors with an acquisition board based on an ATMEGA 328 microprocessor (Atmel MEGA AVR microcontroller). A dedicated measurement chamber was designed and prototyped in acrylonitrile butadiene styrene (ABS) using an Ultimaker3 3D printer. The measurement cell size is 120 × 85 mm. Anthocyanins (red rose) were used as a sensing material in order to functionalize the sensor surface. The sensor was calibrated using different concentrations of oxygen and carbon dioxide, ranging from 5% to 25%, mixed with water vapor in the range from 50% to 90%. The sensor exhibits good repeatability for CO2 concentrations. To better understand the sensor response characteristics, sensitivity and resolution were calculated from the response curves at different working points. The sensitivity is in the order of magnitude of tens to hundreds of µV/% for CO2, and of µV/% in the case of O2. The resolution is in the range of 10−1%–10−3% for CO2, and it is around 10−1% for O2. The system could be specialized for different fields, for environmental, medical, and food applications.

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Roxana Varlan, Anca, and Willy Sansen. "Micromachined conductometric p(CO2) sensor." Sensors and Actuators B: Chemical 44, no. 1-3 (October 1997): 309–15. http://dx.doi.org/10.1016/s0925-4005(97)00223-2.

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Suriano, Domenico, Gennaro Cassano, and Michele Penza. "Design and Development of a Flexible, Plug-and-Play, Cost-Effective Tool for on-Field Evaluation of Gas Sensors." Journal of Sensors 2020 (August 1, 2020): 1–20. http://dx.doi.org/10.1155/2020/8812025.

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Atmospheric pollution is one of the biggest concerns for public health. Air quality monitoring is currently performed by expensive and cumbersome monitoring stations. For this reason, they are sparse, and therefore, inadequate to provide enough accurate information on the personal exposure to pollutant gases. The current worldwide trend to address this issue consists in the use of low-cost small gas sensors, already available on the market, with a wide range of costs and performances. However, the performance of these sensors is heavily affected by the environmental conditions of the specific location used for their deployment. For this reason, it is of fundamental importance to test them in real-world scenarios. Field evaluation of sensor performance could be a challenging task because, on the one hand, they have heterogeneous output signals, and on the other hand, there is no widely shared evaluation protocol. The SentinAir system has been designed and developed to facilitate this task. It can carry out performance evaluations for any type of sensor thanks to its configurable and adaptable sensing capability, multiple wireless sensor network compatibility, flexibility, and usability. In order to evaluate SentinAir capabilities and functionalities, the performances of CO2, NO2, and O3 sensors were tested in real-world scenarios against reference instruments. To the best of our knowledge, there is no previous study providing information about the performance of SP-61 (O3 sensor), IRC-A1 (CO2 sensor), and TDS5008 (CO2 sensor) achieved during on-field tests. On the contrary, results obtained by OXB431 (O3 sensor) and NO2B43F (NO2 sensor) are consistent with the ones shown in previous studies carried out in similar conditions. During validation tests, we have found R2=0.507 for the best performing NO2 sensor, and R2=0.668 for the best O3 sensor. Concerning the indoor experiment, the best CO2 sensor performance showed an excellent R2=0.995. In conclusion, the effectiveness of this tool in evaluating the performance of heterogeneous gas sensors in different real-world scenarios has been demonstrated. Therefore, we anticipate that the use of SentinAir will facilitate researchers to carry out these challenging tasks.

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Oguchi, Kimio, and Ryoya Ozawa. "Human Presence Recognition in a Closed Space by using Cost-effective CO2 Sensor and the Information Gain Processing Method." Indonesian Journal of Electrical Engineering and Computer Science 5, no. 3 (March 1, 2017): 549. http://dx.doi.org/10.11591/ijeecs.v5.i3.pp549-555.

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The recent rapid progress in ICT technologies such as smart/intelligent sensor devices, broadband/ubiquitous networks, and Internet of everything (IoT) has advanced the penetration of sensor networks and their applications. The requirements of human daily life, security, energy efficiency, safety, comfort, and ecological, can be achieved with the help of these networks and applications. Traditionally, if we want some information on, for example, environment status, a variety of dedicated sensors is needed. This will increase the number of sensors installed and thus system cost, sensor data traffic loads, and installation difficulty. Therefore, we need to find redundancies in the captured information or interpret the semantics captured by non-dedicated sensors to reduce sensor network overheads. This paper clarifies the feasibility of recognizing human presence in a space by processing information captured by other than dedicated sensors. It proposes a method and implements it as a cost-effective prototype sensor network for a university library. This method processes CO2 concentration, originally designed to check environment status. In the experiment, training data is captured with none, one, or two subjects. The information gain (IG) method is applied to the resulting data, to set thresholds and thus judge the number of people. Human presence (none, one or two people) is accurately recognized from the CO2 concentration data. The experiments clarify that a CO2 sensor in set in a small room to check environment status can recognize the number of humans in the room with more than 70 % accuracy. This eliminates the need for an extra sensor, which reduces sensor network cost.

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Bellancini, Michele, Laura Cercenelli, Stefano Severi, Guido Comai, and Emanuela Marcelli. "Development of a CO2 Sensor for Extracorporeal Life Support Applications." Sensors 20, no. 13 (June 27, 2020): 3613. http://dx.doi.org/10.3390/s20133613.

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Measurement of carbon dioxide (CO2) in medical applications is a well-established method for monitoring patient’s pulmonary function in a noninvasive way widely used in emergency, intensive care, and during anesthesia. Even in extracorporeal-life support applications, such as Extracorporeal Carbon Dioxide Removal (ECCO2R), Extracorporeal Membrane Oxygenation (ECMO), and cardiopulmonary by-pass (CPB), measurement of the CO2 concentration in the membrane oxygenator exhaust gas is proven to be useful to evaluate the treatment progress as well as the performance of the membrane oxygenator. In this paper, we present a new optical sensor specifically designed for the measurement of CO2 concentration in oxygenator exhaust gas. Further, the developed sensor allows measurement of the gas flow applied to the membrane oxygenator as well as the estimation of the CO2 removal rate. A heating module is implemented within the sensor to avoid water vapor condensation. Effects of temperature on the sensor optical elements of the sensors are disclosed, as well as a method to avoid signal–temperature dependency. The newly developed sensor has been tested and compared against a reference device routinely used in clinical practice in both laboratory and in vivo conditions. Results show that sensor accuracy fulfills the requirements of the ISO standard, and that is suitable for clinical applications.

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Ma, Ying, Kittithat Promthaveepong, and Nan Li. "CO2-Responsive Polymer-Functionalized Au Nanoparticles for CO2 Sensor." Analytical Chemistry 88, no. 16 (July 26, 2016): 8289–93. http://dx.doi.org/10.1021/acs.analchem.6b02133.

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Suzuki, Takuya, Frieder Lauxmann, Andre Sackmann, Anna Staerz, Udo Weimar, Christoph Berthold, and Nicolae Barsan. "Operando Investigations of Rare-Earth Oxycarbonate CO2 Sensors." Proceedings 2, no. 13 (November 26, 2018): 801. http://dx.doi.org/10.3390/proceedings2130801.

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In this work, we have succeeded in synthesizing monoclinic and hexagonal La2O2CO3 using two different routes and revealed that both of them are sensitive to CO2 to the same degree. Moreover, we observed that the resistance of the sensor based on hexagonal phase is much higher and more stable than the one of the sensors based on the monoclinic phase. Using Operando and time resolved XRD measurements, we have also demonstrated that the resistivity of the sensor based on monoclinic La2O2CO3 increases because of the material transformation into the hexagonal phase during an exemplarily aging process.

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Yasmin Sofea Rosland, Nur, Khadijah Ismail, Siti Nooraya Mohd Tawil, and Siti Hasnawati Jamal. "PEDOT:PSS/GO NANOCOMPOSITE FOR INDOOR CO2 SENSOR." International Journal of Advanced Research 9, no. 08 (August 31, 2021): 473–81. http://dx.doi.org/10.21474/ijar01/13292.

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Carbon dioxide (CO2) which is a colourless and odourless gas, requires an efficient detection, as excessive amount in the environment would possibly leads to global warming. This work discusses on an environmentally friendly and non-toxic CO2 sensor for indoor air monitoring. The fabricated sensor is developed by using poly(3,4ethylenedioxythiophene):poly(4styrenesulfonate)/ graphene oxide (PEDOT:PSS/GO) nanocomposite. Nanocomposite characterisations are performed by using field-emission scanning electron microscope (FESEM) and X-ray diffraction (XRD) to confirm excellent properties of PEDOT:PSS and GO as suitable materials for CO2 sensor development. Fabrication of one layer PEDOT:PSS/GO nanocomposite on environmentally friendly kaolin-coated paper substrate via dip coating method shows good electrical conductivity of 0.25 S. At room temperature, at fixed CO2 flow rate of 0.05 l/min, the fabricated sensor response time is 32 s, with sensor response and sensitivity of 0.8 and 16/l/min respectively. With fast chemiresistive response towards CO2 molecules, the fabricated sensor provides promising results for indoor CO2 monitoring.

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von Oppeln-Bronikowski, Nicolai, Brad de Young, Dariia Atamanchuk, and Douglas Wallace. "Glider-based observations of CO2 in the Labrador Sea." Ocean Science 17, no. 1 (January 4, 2021): 1–16. http://dx.doi.org/10.5194/os-17-1-2021.

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Abstract. Ocean gliders can provide high-spatial- and temporal-resolution data and target specific ocean regions at a low cost compared to ship-based measurements. An important gap, however, given the need for carbon measurements, is the lack of capable sensors for glider-based CO2 measurements. We need to develop robust methods to evaluate novel CO2 sensors for gliders. Here we present results from testing the performance of a novel CO2 optode sensor (Atamanchuk et al., 2014), deployed on a Slocum glider, in the Labrador Sea and on the Newfoundland Shelf. This paper (1) investigates the performance of the CO2 optode on two glider deployments, (2) demonstrates the utility of using the autonomous SeaCycler profiler mooring (Send et al., 2013; Atamanchuk et al., 2020) to improve in situ sensor data, and (3) presents data from moored and mobile platforms to resolve fine scales of temporal and spatial variability of O2 and pCO2 in the Labrador Sea. The Aanderaa CO2 optode is an early prototype sensor that has not undergone rigorous testing on a glider but is compact and uses little power. Our analysis shows that the sensor suffers from instability and slow response times (τ95>100 s), affected by different behavior when profiling through small (<3 ∘C) vs. large (>10 ∘C) changes in temperature over similar time intervals. We compare the glider and SeaCycler O2 and CO2 observations and estimate the glider data uncertainty as ± 6.14 and ± 44.01 µatm, respectively. From the Labrador Sea mission, we point to short timescales (<7 d) and distance (<15 km) scales as important drivers of change in this region.

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Fernández-Ramos, María Dolores, Fátima Mirza-Montoro, Luis Fermín Capitán-Vallvey, and Isabel María Pérez de Vargas-Sansalvador. "Near Infrared Sensor to Determine Carbon Dioxide Gas Based on Ionic Liquid." Coatings 11, no. 2 (January 30, 2021): 163. http://dx.doi.org/10.3390/coatings11020163.

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In this study we present an NIR carbon dioxide gas sensor based on an inner filter process that includes an ionic liquid (IL), 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIMBF4), to improve its stability, dynamic behavior and lifetime, which are usually the main drawbacks with these sensors. The presence of CO2 causes a displacement of a simple boron-dipyrromethene-type fluorophore, azaBODIPY, as the pH indicator towards its acid form. This increases the emission intensity of Cr(III)-doped gadolinium aluminium borate (GAB) as the luminophore. The characterization of the prepared sensor was carried out and a discussion of the results is presented. The response and recovery times improved considerably, 23 and 49 s, respectively, with respect to the sensor without IL, at 60 and 120 s, respectively,. Additionally, the measurement range is extended when using IL, able in this case to measure in the complete range up to 100% CO2; without IL the measurement range is limited to 60% CO2. The detection limit ranges from 0.57% CO2 without IL to 0.26% CO2 when IL is added. The useful lifetime of the sensing membrane was 20 days for membranes with IL and only 6 days for membranes without IL, with the sensor always kept in the dark and without the need to maintain a special atmosphere.

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Kodu, Margus, Tea Avarmaa, Hugo Mändar, Rando Saar, and Raivo Jaaniso. "Structure-Dependent CO2 Gas Sensitivity of La2O2CO3 Thin Films." Journal of Sensors 2017 (2017): 1–6. http://dx.doi.org/10.1155/2017/9591081.

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Rare earth oxycarbonates are potential candidate materials for constructing simple and low-cost chemiresistive sensors for monitoring carbon dioxide (CO2) gas in the living and working environment for personal comfort and health reasons. Also, measurement of CO2 concentrations is needed in many industrial processes. Specifically, sol-gel made nanoparticles of Nd and La oxycarbonates have been studied previously as novel CO2 gas sensor materials. In this paper, pulsed laser deposition of La oxycarbonate (La2O2CO3) thin films was studied and structural properties of obtained thin films were characterized. Also, CO2 gas sensing ability of synthesized films was evaluated. The films deposited under CO2 partial pressure in various conditions were all Raman amorphous. In situ or ex situ annealing procedure at high CO2 partial pressure was needed for obtaining crystalline La2O2CO3 films, whereby hexagonal and monoclinic polymorphs were obtained in ex situ and in situ processes, respectively. Sensor structure, made using in situ process, was sensitive to CO2 gas and showed relatively fast response and recovery characteristics.

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De Acha, Nerea, César Elosúa, and Francisco J. Arregui. "Development of an Aptamer Based Luminescent Optical Fiber Sensor for the Continuous Monitoring of Hg2+ in Aqueous Media." Sensors 20, no. 8 (April 22, 2020): 2372. http://dx.doi.org/10.3390/s20082372.

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A fluorescent optical fiber sensor for the detection of mercury (Hg2+) ions in aqueous solutions is presented in this work. The sensor was based on a fluorophore-labeled thymine (T)-rich oligodeoxyribonucleotide (ON) sequence that was directly immobilized onto the tip of a tapered optical fiber. In the presence of mercury ions, the formation of T–Hg2+-T mismatches quenches the fluorescence emission by the labeled fluorophore, which enables the measurement of Hg2+ ions in aqueous solutions. Thus, in contrast to commonly designed sensors, neither a fluorescence quencher nor a complementary ON sequence is required. The sensor presented a response time of 24.8 seconds toward 5 × 10−12 M Hg2+. It also showed both good reversibility (higher than the 95.8%) and selectivity: the I0/I variation was 10 times higher for Hg2+ ions than for Mn2+ ions. Other contaminants examined (Co2+, Ag+, Cd2+, Ni2+, Ca2+, Pb2+, Mn2+, Zn2+, Fe3+, and Cu2+) presented an even lower interference. The limit of detection of the sensor was 4.73 × 10−13 M Hg2+ in buffer solution and 9.03 × 10−13 M Hg2+ in ultrapure water, and was also able to detect 5 × 10−12 M Hg2+ in tap water.

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Loghin, Florin C., Aniello Falco, Jose F. Salmeron, Paolo Lugli, Alaa Abdellah, and Almudena Rivadeneyra. "Fully Transparent Gas Sensor Based on Carbon Nanotubes." Sensors 19, no. 20 (October 22, 2019): 4591. http://dx.doi.org/10.3390/s19204591.

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In this paper, we demonstrate the feasibility of realization of transparent gas sensors based on carbon nanotubes (CNTs). Both sensing layer and electrodes consist of CNTs deposited by spray deposition. The transparent sensor—with a transmittance higher than 60% in both sensing layer and electrodes—is characterized towards NH3 and CO2 and compared with a reference sensor with the same active layer but evaporated Au electrodes. In particular, the sensitivity towards NH3 is virtually identical for both reference and transparent sensors, whereas the transparent device exhibits higher sensitivity to CO2 than the reference electrode. The effect of the spacing among consecutive electrodes is also studied, demonstrating that a wider spacing in fully CNT based sensors results in a higher sensitivity because of the higher sensing resistance, whereas this effect was not observed in gold electrodes, as their resistance can be neglected with respect to the resistance of the CNT sensing layer. Overall, the transparent sensors show performance comparable—if not superior—to the traditionally realized ones, opening the way for seamlessly integrated sensors, which do not compromise on quality.

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Takakura, Tadashi, Haruki Sunagawa, Maro Tamaki, Takae Usui, and Naoki Taniai. "IN SITE NET PHOTOSYNTHESIS MEASUREMENT OF A PLANT CANOPY IN A SINGLE-SPAN GREENHOUSE." JOURNAL OF ADVANCES IN AGRICULTURE 7, no. 2 (May 30, 2017): 1015–20. http://dx.doi.org/10.24297/jaa.v7i2.6092.

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Using newly developed sensor units that were more compact and accurate than earlier units (Takakura et al., 2009), this study was conducted to estimate the net photosynthesis of a plant canopy in a practical greenhouse during plant cultivation. Net photosynthesis and the ventilation flow rate are two unknowns in this greenhouse system, with adequate growth of bitter gourd plants. Environmental conditions related to evapotranspiration from the canopy and CO2 flux from the soil surface were measured respectively using the developed sensor units and a box-type CO2 concentration sensor. Heat flux from the soil was also measured. Two equations were solved: one for CO2 balance and one for water vapor balance. On-line monitoring of net photosynthesis is possible using simple and inexpensive sensors, but the obtained data of the canopy photosynthesis were scattered because of frequent changes in the ventilation amount. Furthermore, improved sensor units revealed that the evapotranspiration of the canopy was linearly related to net solar radiation in the greenhouse.

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Challener, William A., Ansas M. Kasten, Sachin Dekate, Dimitri Dylov, Reza Ghandi, Renato Guida, S. M. Hasan, Thaddeus Czauski, Russell Craddock, and Roger Jones. "Multipoint Pressure and Temperature Sensing Fiber Optic Cable for Monitoring CO2 Sequestration." MRS Advances 1, no. 21 (2016): 1501–12. http://dx.doi.org/10.1557/adv.2016.119.

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ABSTRACTA highly accurate multi-point pressure measurement system based on MEMS pressure sensors spliced into a fiber optic cable and suitable for downhole deployment in a CO2 sequestration well was designed, developed and tested in the laboratory. An interrogator system based on a pulsed laser excitation was shown to be capable of multiple (potentially 60+) point sensor measurements on a single fiber. The interrogator was interfaced with the GE PredixTM industrial internet to demonstrate a remote monitoring system. Sensor packages were fabricated and tested at high temperatures and pressures in supercritical CO2. Environmental and stress testing of the sensor components and package indicated areas in which the design of the package should be further improved.

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Huber, J., C. Weber, A. Eberhardt, and J. Wöllenstein. "Photoacoustic CO2-Sensor for Automotive Applications." Procedia Engineering 168 (2016): 3–6. http://dx.doi.org/10.1016/j.proeng.2016.11.111.

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Wierzbicka, M., P. Pasierb, and M. Rekas. "CO2 sensor studied by impedance spectroscopy." Physica B: Condensed Matter 387, no. 1-2 (January 2007): 302–12. http://dx.doi.org/10.1016/j.physb.2006.04.020.

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Andò, B., S. Baglio, G. Di Pasquale, A. Pollicino, S. D’Agata, C. Gugliuzzo, C. Lombardo, and G. Re. "An Inkjet Printed CO2 Gas Sensor." Procedia Engineering 120 (2015): 628–31. http://dx.doi.org/10.1016/j.proeng.2015.08.755.

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Vanus, Jan, Jan Nedoma, Marcel Fajkus, and Radek Martinek. "Design of a New Method for Detection of Occupancy in the Smart Home Using an FBG Sensor." Sensors 20, no. 2 (January 10, 2020): 398. http://dx.doi.org/10.3390/s20020398.

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This article introduces a new way of using a fibre Bragg grating (FBG) sensor for detecting the presence and number of occupants in the monitored space in a smart home (SH). CO2 sensors are used to determine the CO2 concentration of the monitored rooms in an SH. CO2 sensors can also be used for occupancy recognition of the monitored spaces in SH. To determine the presence of occupants in the monitored rooms of the SH, the newly devised method of CO2 prediction, by means of an artificial neural network (ANN) with a scaled conjugate gradient (SCG) algorithm using measurements of typical operational technical quantities (indoor temperature, relative humidity indoor and CO2 concentration in the SH) is used. The goal of the experiments is to verify the possibility of using the FBG sensor in order to unambiguously detect the number of occupants in the selected room (R104) and, at the same time, to harness the newly proposed method of CO2 prediction with ANN SCG for recognition of the SH occupancy status and the SH spatial location (rooms R104, R203, and R204) of an occupant. The designed experiments will verify the possibility of using a minimum number of sensors for measuring the non-electric quantities of indoor temperature and indoor relative humidity and the possibility of monitoring the presence of occupants in the SH using CO2 prediction by means of the ANN SCG method with ANN learning for the data obtained from only one room (R203). The prediction accuracy exceeded 90% in certain experiments. The uniqueness and innovativeness of the described solution lie in the integrated multidisciplinary application of technological procedures (the BACnet technology control SH, FBG sensors) and mathematical methods (ANN prediction with SCG algorithm, the adaptive filtration with an LMS algorithm) employed for the recognition of number persons and occupancy recognition of selected monitored rooms of SH.

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Chen, Guo Feng, Hsiao Pin Tsai, Ping Shan Lai, and Ming Yuan Liao. "Functionalized Mn2+ Doped Zinc Sulfide Quantum Dots as a Metal Ion Sensor for Industrial Wastes." Applied Mechanics and Materials 284-287 (January 2013): 138–42. http://dx.doi.org/10.4028/www.scientific.net/amm.284-287.138.

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L-cysteine capped Mn2+-doped ZnS quantum dots are prepared as a fluorescence probe for the detection of heavy metal contaminants, such as As2O42-, Cd2+, CrO42-, Ni2+, Zn2+, Ca2+, Fe2+, Cu2+, Pb2+, Co2+ and Mn2+ ions. The results show L-cysteine capped Mn2+-doped ZnS quantum dots exhibit good sensitivity and selectivity for the detection of copper ions. The relationship between the detection limit, linear range and the concentration of quantum dots are examined. The optimum fluorescence sensor is obtained at the L-cysteine-ZnS QDs concentration of 2 mg/mL and pH 7.0 in phosphate buffer. The limit of detection for this sensor system is 0.2 ppm with the linear range between 0.5 and 20 ppm. The effect of foreign ions from Mn2+, Fe2+, Co2+ and Ni2+ for the detection of Cu2+ solution is also evaluated. The results show there is no significant difference on the measurement of quenching effect.

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Cao, Xin Liang. "The Controllable Flexible Features of ZnO Thin Film Gas Sensor." Advanced Materials Research 335-336 (September 2011): 478–82. http://dx.doi.org/10.4028/www.scientific.net/amr.335-336.478.

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For different gas sensing, the preparation of Zinc Oxide (ZnO) thin film gas sensor has its particularity. In this paper, three kinds of preparation methods, fitting for CO and methane and CO2 sensing, are introduced. Moreover, the sensitivity is respectively analyzed as gas sensors. The reference is provided for the preparation and applications of ZnO thin film gas sensor.

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Niklas, Christian, Stephan Bauke, Fabian Müller, Kai Golibrzuch, Hainer Wackerbarth, and Georgios Ctistis. "Quantitative measurement of combustion gases in harsh environments using NDIR spectroscopy." Journal of Sensors and Sensor Systems 8, no. 1 (March 1, 2019): 123–32. http://dx.doi.org/10.5194/jsss-8-123-2019.

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Abstract. The global climate change calls for more environmentally friendly use of energy and has led to stricter limits and regulations for the emissions of various greenhouse gases. Consequently, there is nowadays an increasing need for the detection of exhaust and natural gases. This need leads to an ever-growing market for gas sensors, which, at the moment, is dominated by chemical sensors. Yet, the increasing demands to also measure under harsh environmental conditions pave the way for non-invasive measurements and thus optical detection techniques. Here, we present the development of two optical detection systems using non-dispersive infrared absorption spectroscopy (NDIR). One system is intended for civilian use, capable of detecting both CO as well as CO2 in the range of 4–5 µm. Furthermore, restrictions regarding size and economic viability are put on this sensor so it can compete with existing sensors. For CO2, an estimated resolution of 444 ppm is achieved, which is competitive with established sensors on the market. For CO an estimated resolution of 1401 ppm was achieved, rendering it necessary to improve this sensor to be competitive with other available sensors. The second system is used in an exhaust system and is capable of detecting CO2 at 3.2 µm facing cross-sensitivity with H2O. A data analysis method is described to separate the CO2 and H2O signals, revealing a time resolution of 33 µs.

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Lehto, Juhani. "CO2 exakt einstellen." UmweltMagazin 50, no. 08-09 (2020): 48–49. http://dx.doi.org/10.37544/0173-363x-2020-08-09-48.

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In den Niederlanden versuchen Forscher, den CO2-Gehalt in Gewächshäusern so einzustellen, dass etwa reichhaltig Gemüse und Obst geerntet werden kann. Im Mittelpunkt steht dabei ein CO2-Sensor einer finnischen Firma.

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Wang, Hai Rong, Jun Qiang Ren, Guo Liang Sun, and Di Cen. "Micro CO₂ Sensor Based on Li₂CO₃, Pt | Li₃PO₄ | Pt, Li₂TiO₃-TiO₂ Structure." Applied Mechanics and Materials 44-47 (December 2010): 2747–51. http://dx.doi.org/10.4028/www.scientific.net/amm.44-47.2747.

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This paper presents a micro solid electrolyte CO2 gas sensor in which Li2CO3, Li2TiO3-TiO2 serves as sensing and reference electrodes respectively, and the Li3PO4 film acts as the electrolyte. The sensor was constructed in the sequent layers of O2, CO2, Li2CO3, Pt | Li3PO4 | Pt, Li2TiO3-TiO2, O2, CO2 on the Al2O3 substrate by MEMS process. Experimental results indicate that the micro solid-electrolyte CO2 gas sensor has a relatively rapid speed of response. By discussions, we may find that the improved performance will be realized by optimizing the primary parameters of the sensor.

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Amsar, Amsar, Khairuman Khairuman, and Marlina Marlina. "Perancangan Alat Pendeteksi CO2 Menggunakan Sensor MQ-2 Berbasis Internet Of Thing." METHOMIKA: Jurnal Manajemen Informatika dan Komputerisasi Akuntansi 4, no. 1 (April 1, 2020): 73–79. http://dx.doi.org/10.46880/jmika.v4i1.143.

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Salah satu gas yang sangat berbahaya bagi kesehatan manusia adalah Gas CO2, untuk mengetahui kadar di tempat tertentu mengandung CO2 tanpa menggunakan alat bantu pendeteksi akan sulit dilakukan, karena Gas CO2 tersebut merupakan zat yang tidak dapat dilihat langsung oleh mata manusia, maka dalam penelitian ini dirancang sebuah alat pendeteksi CO2 yang dapat memberikan notifikasi kadar CO2 ke telegram berbasis Internet Of Things (IOT) . dalam peneltian ini alat yang digunakan untuk pengukuran kadar CO2 dengan menggunakan sensor MQ-2 untuk mendeteksi kadar dari karbon dioksida, sehingga kadar CO2 yang terdeteksi oleh sensor selanjutnya dikirim melalui jaringan IOT berbasis notifikasi via telegram, notifikasi pada telegram sebagai media pemberi inforamsi pada alat yang dibangun ini dengan lima kategori yaitu: baik, sedang, tidak sehat, sangat tidak sehat dan berbahaya, adapun hasil dari rentang diperoleh jika sensor MQ-2 mendeteksi karbon dioksida dengan rentang 0-50 ppm, maka kondisi udara baik, apabila sensor mendeteksi karbondioksida dengan rentang 51-100 ppm, maka kondisi udara sedang, apabila sensor mendeteksi karbondioksida dengan rentang 101-199 ppm, maka kondisi udara tidak sehat, apabila sensor mendeteksi karbondioksida dengan rentang 200-299 ppm, maka kondisi udara sangat tidak sehat, dan apabila sensor mendeteksi karbondioksida dengan rentang 300 ppm, maka notifikasi ke telegram berbahaya.

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Sya’bani, Ashari, Indra Chandra, Lutfi Ikbal Majid, Furqan Vaicdan, Robbi Adam Aldino Barus, Arief Abdurrachman, and Rahmat Awaludin Salam. "Pemantauan Konsentrasi PM2.5 dan CO2 Berbasis Low-Cost Sensor secara Real-Time di Cekungan Udara Bandung Raya." Jurnal Teknologi Lingkungan 21, no. 1 (January 30, 2020): 9–15. http://dx.doi.org/10.29122/jtl.v21i1.3707.

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ABSTRACTField observation of PM2.5 and CO2 concentrations and meteorological conditions using low-cost sensors in real-time was carried out in the Greater Bandung air basin on Mar. 12 – Apr. 25, 2019. PM2.5 and CO2 sensors, as well as detectors of meteorological parameters, have been calibrated in the Laboratory. The instruments were placed in two locations (±300 m apart horizontally and ±20 m vertically), namely Tokong Nanas Building (Location 1 / L1) and Deli Building (L2), Telkom University, Bandung. Data was stored in the data logger and sent to the cloud database every 2-min through the GSM module. The results show that the same air mass in both locations has identified, except for some events that are affected by anthropogenic activities (those concentrations in L2 L1) and wind speed/direction (time delay). The daily-average PM2.5 and CO2 concentrations at L1 and L2 are 52 µg m-3 and 580 ppm, and 70 µg m-3 and 809 ppm. PM2.5 and CO2 mass concentrations relatively higher (±172 µg m-3 and 916 ppm) at night due to a stable atmosphere (potential temperature, dθ/dz 0, typical data from 20:00 to 3:00 local time), lower planetary boundary layer, and mixed local emissions and transboundary air pollutants. Meanwhile, lower CO2 concentrations in daytime mostly occur due to the activity of vegetation, which actively absorbs CO2 in the photosynthesis process. The fluctuation of those concentrations due to polluted air suggests that the performances of low-cost sensors can be adequately used properly for ambient air quality monitoring. Keywords: CO2, low-cost sensors, PM2.5, potential temperatureABSTRAKPemantauan konsentrasi PM2.5 dan CO2 serta kondisi meteorologi berbasis low-cost sensors secara real-time di cekungan udara Bandung Raya telah dilakukan pada 12 Maret-25 April 2019. Sensor PM2.5 dan CO2, serta detektor parameter meteorologi telah dikalibrasi di Laboratorium. Alat ukur ditempatkan di dua lokasi dengan perbedaan jarak ±300 m dan ketinggian ±20 m, yaitu Gedung Tokong Nanas (Lokasi 1 / L1) dan Gedung Deli (L2), Universitas Telkom, Bandung. Komunikasi data menggunakan modul GSM (SIM900A) dan data disimpan di data logger dan dikirimkan ke cloud database per 2 menit. Hasil pengukuran menunjukkan bahwa massa udara di kedua lokasi memiliki tren data konsentrasi PM2.5 dan CO2 yang relatif homogen, kecuali pada beberapa kejadian yang dipengaruhi oleh aktivitas antropogenik (konsentrasi PM2.5 dan CO2 di L2 L1) serta arah dan kecepatan angin (adanya perbedaan konsentrasi massa PM2.5 akibat penundaan waktu). Rerata harian konsentrasi PM2.5 dan CO2 di L1 dan L2 berturut-turut adalah 52 µg m-3 dan 580 ppm serta 70 µg m-3 dan 809 ppm. Konsentrasi massa PM2.5 dan CO2 yang relatif lebih tinggi (±172 µg m-3 dan 916 ppm) di malam hari akibat atmosfer yang lebih stabil (temperatur potensial, dθ/dz 0, tipikal dari pukul 20:00-03:00), penurunan planetary boundary layer, dan terjadinya pencampuran partikulat lokal dengan polutan udara lintas batas. Sedangkan, konsentrasi CO2 yang relatif lebih rendah di siang hari sebagian besar terjadi akibat aktivitas vegetasi yang aktif menyerap CO2 pada proses fotosintesis. Fluktuasi konsentrasi karena udara tercemar menunjukkan bahwa kinerja low-cost sensors dapat digunakan dengan baik untuk memantau kualitas udara di atmosfer.Kata kunci: CO2, low-cost sensor, PM2.5, temperatur potensial

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Lee, Joseph K., Andreas Christen, Rick Ketler, and Zoran Nesic. "A mobile sensor network to map carbon dioxide emissions in urban environments." Atmospheric Measurement Techniques 10, no. 2 (March 1, 2017): 645–65. http://dx.doi.org/10.5194/amt-10-645-2017.

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Abstract. A method for directly measuring carbon dioxide (CO2) emissions using a mobile sensor network in cities at fine spatial resolution was developed and tested. First, a compact, mobile system was built using an infrared gas analyzer combined with open-source hardware to control, georeference, and log measurements of CO2 mixing ratios on vehicles (car, bicycles). Second, two measurement campaigns, one in summer and one in winter (heating season) were carried out. Five mobile sensors were deployed within a 1 × 12. 7 km transect across the city of Vancouver, BC, Canada. The sensors were operated for 3.5 h on pre-defined routes to map CO2 mixing ratios at street level, which were then averaged to 100 × 100 m grid cells. The averaged CO2 mixing ratios of all grids in the study area were 417.9 ppm in summer and 442.5 ppm in winter. In both campaigns, mixing ratios were highest in the grid cells of the downtown core and along arterial roads and lowest in parks and well vegetated residential areas. Third, an aerodynamic resistance approach to calculating emissions was used to derive CO2 emissions from the gridded CO2 mixing ratio measurements in conjunction with mixing ratios and fluxes collected from a 28 m tall eddy-covariance tower located within the study area. These measured emissions showed a range of −12 to 226 CO2 ha−1 h−1 in summer and of −14 to 163 kg CO2 ha−1 h−1 in winter, with an average of 35.1 kg CO2 ha−1 h−1 (summer) and 25.9 kg CO2 ha−1 h−1 (winter). Fourth, an independent emissions inventory was developed for the study area using buildings energy simulations from a previous study and routinely available traffic counts. The emissions inventory for the same area averaged to 22.06 kg CO2 ha−1 h−1 (summer) and 28.76 kg CO2 ha−1 h−1 (winter) and was used to compare against the measured emissions from the mobile sensor network. The comparison on a grid-by-grid basis showed linearity between CO2 mixing ratios and the emissions inventory (R2 = 0. 53 in summer and R2 = 0. 47 in winter). Also, 87 % (summer) and 94 % (winter) of measured grid cells show a difference within ±1 order of magnitude, and 49 % (summer) and 69 % (winter) show an error of less than a factor 2. Although associated with considerable errors at the individual grid cell level, the study demonstrates a promising method of using a network of mobile sensors and an aerodynamic resistance approach to rapidly map greenhouse gases at high spatial resolution across cities. The method could be improved by longer measurements and a refined calculation of the aerodynamic resistance.

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Sugrue, Rebecca A., Chelsea V. Preble, and Thomas W. Kirchstetter. "Comparing the Use of High- to Low-Cost Black Carbon and Carbon Dioxide Sensors for Characterizing On-Road Diesel Truck Emissions." Sensors 20, no. 23 (November 24, 2020): 6714. http://dx.doi.org/10.3390/s20236714.

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The exhaust plume capture method is a commonly used approach to measure pollutants emitted by in-use heavy-duty diesel trucks. Lower cost sensors, if used in place of traditional research-grade analyzers, could enable wider application of this method, including use as a monitoring tool to identify high-emitting trucks that may warrant inspection and maintenance. However, low-cost sensors have for the most part only been evaluated under ambient conditions as opposed to source-influenced environments with rapidly changing pollutant concentrations. This study compared black carbon (BC) emission factors determined using different BC and carbon dioxide (CO2) sensors that range in cost from $200 to $20,000. Controlled laboratory experiments show that traditional zero and span steady-state calibration checks are not robust indicators of sensor performance when sampling short duration concentration peaks. Fleet BC emission factor distributions measured at two locations at the Port of Oakland in California with 16 BC/CO2 sensor pairs were similar, but unique sensor pairs identified different high-emitting trucks. At one location, the low-cost PP Systems SBA-5 agreed on the classification of 90% of the high emitters identified by the LI-COR LI-7000 when both were paired with the Magee Scientific AE33. Conversely, lower cost BC sensors when paired with the LI-7000 misclassified more than 50% of high emitters when compared to the AE33/LI-7000. Confidence in emission factor quantification and high-emitter identification improves with larger integrated peak areas of CO2 and especially BC. This work highlights that sensor evaluation should be conducted under application-specific conditions, whether that be for ambient air monitoring or source characterization.

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Davydova, Marina, Alexandr Laposa, Jiri Smarhak, Alexander Kromka, Neda Neykova, Josef Nahlik, Jiri Kroutil, Jan Drahokoupil, and Jan Voves. "Gas-sensing behaviour of ZnO/diamond nanostructures." Beilstein Journal of Nanotechnology 9 (January 3, 2018): 22–29. http://dx.doi.org/10.3762/bjnano.9.4.

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Microstructured single- and double-layered sensor devices based on p-type hydrogen-terminated nanocrystalline diamond (NCD) films and/or n-type ZnO nanorods (NRs) have been obtained via a facile microwave-plasma-enhanced chemical vapour deposition process or a hydrothermal growth procedure. The morphology and crystal structure of the synthesized materials was analysed with scanning electron microscopy, X-ray diffraction measurements and Raman spectroscopy. The gas sensing properties of the sensors based on i) NCD films, ii) ZnO nanorods, and iii) hybrid ZnO NRs/NCD structures were evaluated with respect to oxidizing (i.e., NO2, CO2) and reducing (i.e., NH3) gases at 150 °C. The hybrid ZnO NRs/NCD sensor showed a remarkably enhanced NO2 response compared to the ZnO NRs sensor. Further, inspired by this special hybrid structure, the simulation of interaction between the gas molecules (NO2 and CO2) and hybrid ZnO NRs/NCD sensor was studied using DFT calculations.

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Kim, Han Ji, Jung Woon Choi, Shin Do Kim, and Kwang Soo Yoo. "Thick-Film CO₂ Sensors Based on NASICON Synthesized by a Sol-Gel Process." Materials Science Forum 544-545 (May 2007): 925–28. http://dx.doi.org/10.4028/www.scientific.net/msf.544-545.925.

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Thick-film CO2 sensors were fabricated using a sodium super ionic conductor (NASICON: Na1+xZr2SixP3-xO12) with a series of Li2CO3-BaCO3 auxiliary phases. The powder of a precursor of NASICON with high purity was synthesized by a sol-gel process. Using the NASICON paste, an electrolyte was prepared on the alumina substrate through screen printing and then sintered at 1000°C for 5 hours. The resulted NASICON thick film was characterized by XRD and FESEM. Within a wide range of CO2 volume ratio concentration from 1,000 to 10,000 ppm, the output of the sensor showed a good electromotive force (EMF) response that was very close to the theoretical value. The sensor attached with a binary carbonate auxiliary phase Li2CO3-BaCO3 (1:2) showed fairly good CO2 sensing properties at 470°C.

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Schmidt, Mark, Peter Linke, Stefan Sommer, Daniel Esser, and Sergiy Cherednichenko. "Natural CO2 Seeps Offshore Panarea: A Test Site for Subsea CO2 Leak Detection Technology." Marine Technology Society Journal 49, no. 1 (January 1, 2015): 19–30. http://dx.doi.org/10.4031/mtsj.49.1.3.

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AbstractDuring RV Poseidon cruise POS469 (May 2014), the distribution of pCO2 in the near field of submarine volcanic gas flares in shallow water depths down to 50 m below sea level was continuously monitored using three different and independent methodologies. In situ nondispersive infrared (NDIR) spectrometry, pH measurements, and onboard membrane inlet mass spectrometry (MIMS) were used to determine the fate of rising CO2 bubbles and the dissolved CO2 plume patterns in a 300 × 400-m working area. The In situ sensor carrier platform, a towed video-controlled water sampling rosette, equipped with CTD sensors, guaranteed excellent ground truthing of seafloor characteristics and bubble discharge. Sensor data and near-seafloor observations indicated that the gas bubbles (<9 mm in diameter, >97 vol.% of CO2) dissolved very rapidly within the first 10 m above seafloor. Bottom water masses enriched with pCO2 (up to 1,100 μatm) show low pH values (up to 7.80) and tend to spread rather downslope west than following the measured weak current in SSE-SSW direction. The 3-D evaluation of pCO2 plume is a valuable tool to back-trace the origin of CO2 leakage when compared with local current regimes, water column CTD data, and seafloor bathymetry. Seep sites offshore Panarea can be used for studying CO2 leakage behavior and testing measuring strategies in shallow waters. Moreover, this area is a naturally designed laboratory to improve existing physicochemical and oceanographic transport models for subsea CO2 leakage.

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Astuti, Irnin Agustina Dwi, and Thoha Firdaus. "Analisis Kandungan CO2 Dengan Sensor dan Berbasis Logger Pro di Daerah Yogyakarta." JIPFRI (Jurnal Inovasi Pendidikan Fisika dan Riset Ilmiah) 1, no. 1 (May 1, 2017): 5–8. http://dx.doi.org/10.30599/jipfri.v1i1.118.

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Penelitian ini bertujuan untuk menganalisis kandungan CO2 di daerah Yogyakarta dengan menggunakan sensor CO2 dan logger pro. Kota Yogyakarta setiap tahunnya mengalami kepadatan penduduk yang menyebabkan pesatnya pemakaian kendaraan bermotor juga. Ini yang menyebabkan tingkat polusi udara di kota Yogyakarta juga semakin buruk akibat polusi kendaraan bermotor maupun industri. Kandungan CO2 yang seharusnya di atmosfer bumi sebesar 381 PPM. Dalam penelitian ini menganalisis kandungan CO2 di sepuluh tempat keramaian di Yogyakarta. Penelitian ini menggunakan sensor gas CO2 Vernier dan di analisis menggunakan software logger pro. Ketika sensor CO2 bekerja selama 5 menit akan muncul pulsa kandungan CO2 pada logger pro, kemudian dicari rata-rata kandungan CO2. Hasil penelitian ini dapat diperoleh uji kandungan CO2 yang paling tinggi adalah di daerah 0 KM Yogyakarta sebesar 973,2 PPM. Hasil ini melebihi nilai batas ambang rata-rata yang seharusnya di atmosfir bumi yaitu 381 PPM. Oleh karena itu perlu ditanami pepohonan dan mengurangi emisi kendaraan bermotor agar tingkat kandungan CO2 di kota Yogyakarta semakin menurun.

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Matsubara, Shogo, Shinichiro Kaneko, Shinji Morimoto, Shoichi Shimizu, Tatsumi Ishihara, and Yusaku Takita. "A practical capacitive type CO2 sensor using CeO2/BaCO3/CuO ceramics." Sensors and Actuators B: Chemical 65, no. 1-3 (June 2000): 128–32. http://dx.doi.org/10.1016/s0925-4005(99)00407-4.

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Andò, Bruno, Salvatore Baglio, Giovanna Di Pasquale, Antonio Pollicino, Salvatore Graziani, Chiara Gugliuzzo, Cristian Lombardo, and Vicenzo Marletta. "Direct Printing of a Multi-Layer Sensor on Pet Substrate for CO2 Detection." Energies 12, no. 3 (February 12, 2019): 557. http://dx.doi.org/10.3390/en12030557.

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The use of inexpensive gas sensors is a real need for many applications requiring the use of disposable sensors. This work deals with the realization and characterization of a low cost CO2 sensor realized by rapid prototyping techniques. In particular, the sensor consists of a set of InterDigiTed electrodes, over which a double sensing layer made of PEDOT/PSS (CLEVIOS™ PHCV4, by H.C.Starck) and a solution of pristine graphene powder has been deposited. A silver nano-particle solution is used for inkjet printing the electrodes onto the PET (PolyEthylene Terephthalate) substrate, through a commercial inkjet printer. The sensing strategy is based on the variation of the electrical conductance of graphene due to gas molecules adsorption. The device responsivity observed in two different operating conditions (50 °C and 60 °C), is 4.0 µΩ/Ω/ppm and 4.7 µΩ/Ω/ppm. The corresponding values of the resolution are 400 ppm and 420 ppm. Main advantages of the developed sensor consist in the cost-effective fabrication techniques and the device flexibility, which are strategic for applications requiring disposable and shapeable devices to be installed into irregular surfaces.

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Bouyer, Patrice, Yuehan Zhou, and Walter F. Boron. "An increase in intracellular calcium concentration that is induced by basolateral CO2 in rabbit renal proximal tubule." American Journal of Physiology-Renal Physiology 285, no. 4 (October 2003): F674—F687. http://dx.doi.org/10.1152/ajprenal.00107.2003.

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Working with isolated perfused S2 proximal tubules, we asked whether the basolateral CO2 sensor acts, in part, by raising intracellular Ca2+ concentration ([Ca2+]i), monitored with the dye fura 2 (or fura-PE3). In paired experiments, adding 5% CO2/22 mM [Formula: see text] (constant pH 7.40) to the bath (basolateral) solution caused [Ca2+]i to increase from 57 ± 3 to 97 ± 9nM( n = 8, P < 0.002), whereas the same maneuver in the lumen had no effect. Intracellular pH (pHi), measured with the dye BCECF, fell by 0.54 ± 0.08 ( n = 14) when we added [Formula: see text] to the lumen. In 14 tubules in which we added [Formula: see text] to the bath, pHi fell by 0.55 ± 0.11 in 9 with a high initial pHi, but rose by 0.28 ± 0.07 in the other 5 with a low initial pHi. Thus it cannot be a pHi change that triggers the [Ca2+]i increase. Introducing to the bath an out-of-equilibrium (OOE) solution containing 20% CO2/no [Formula: see text] caused [Ca2+]i to rise by 62 ± 17 nM ( n = 10), whereas an OOE solution containing 0% CO2/22 mM [Formula: see text] caused only a trivial increase. Removing Ca2+ from the lumen and bath, or adding 10 μM nifedipine (L- and T-type Ca2+-channel blocker) or 2 μM thapsigargin [sarco-(endo) plasmic reticulum Ca2+-ATPase inhibitor] or 4 μM rotenone (mitochondrial inhibitor) to the lumen and bath, failed to reduce the CO2-induced increase in [Ca2+]i. Adding 10 mM caffeine (ryanodine-receptor agonist) had no effect on [Ca2+]i. Thus basolateral CO2, presumably via a basolateral sensor, triggers the release of Ca2+ from a nonconventional intracellular pool.

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S, Subhashini, and Vimala Juliet A. "PEIZORESISTIVE MEMS CANTILEVER BASED CO2 GAS SENSOR." International Journal on Intelligent Electronic Systems 6, no. 2 (2012): 13–17. http://dx.doi.org/10.18000/ijies.30111.

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Liao, Bo, Qin Wei, Kaiyi Wang, and Yexiang Liu. "Study on CuO–BaTiO3 semiconductor CO2 sensor." Sensors and Actuators B: Chemical 80, no. 3 (December 2001): 208–14. http://dx.doi.org/10.1016/s0925-4005(01)00892-9.

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Wang, Hui, Sergei I. Vagin, Bernhard Rieger, and Alkiviathes Meldrum. "An Ultrasensitive Fluorescent Paper-Based CO2 Sensor." ACS Applied Materials & Interfaces 12, no. 18 (April 22, 2020): 20507–13. http://dx.doi.org/10.1021/acsami.0c03405.

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47

Oho, T., T. Tonosaki, K. Isomura, and K. Ogura. "A CO2 sensor operating under high humidity." Journal of Electroanalytical Chemistry 522, no. 2 (April 2002): 173–78. http://dx.doi.org/10.1016/s0022-0728(02)00712-x.

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48

Kürschner, Wolfram M. "Leaf sensor for CO2 in deep time." Nature 411, no. 6835 (May 2001): 247–48. http://dx.doi.org/10.1038/35077181.

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49

S., Subhashini, and Vimala Juliet A. "Peizoresistive MEMS Cantilever based CO2 Gas Sensor." International Journal of Computer Applications 49, no. 18 (July 28, 2012): 6–10. http://dx.doi.org/10.5120/7725-1128.

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50

Cai, Qing Y., Arthur Cammers-Goodwin, and Craig A. Grimes. "A wireless, remote query magnetoelastic CO2 sensor." Journal of Environmental Monitoring 2, no. 6 (2000): 556–60. http://dx.doi.org/10.1039/b004929h.

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Journal articles on the topic 'Sensor CO2'

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