scholarly journals Continuous methane concentration measurements at the Greenland ice sheet–atmosphere interface using a low-cost, low-power metal oxide sensor system

2020 ◽  
Vol 13 (6) ◽  
pp. 3319-3328
Author(s):  
Christian Juncher Jørgensen ◽  
Jacob Mønster ◽  
Karsten Fuglsang ◽  
Jesper Riis Christiansen
Keyword(s):  
Metal Oxide ◽  
Low Power ◽  
Low Cost ◽  
Relative Concentration ◽  
Ice Sheet ◽  
Greenland Ice Sheet ◽  
Concentration Difference ◽  
Calibration Period ◽  
Field Calibration ◽  
Metal Oxide Sensor

Abstract. In this paper, the performance of a low-cost and low-power methane (CH4) sensing system prototype based on a metal oxide sensor (MOS) sensitive to CH4 is tested in a natural CH4-emitting environment at the Greenland ice sheet (GrIS). We investigate if the MOS could be used as a supplementary measurement technique for monitoring CH4 emissions from the GrIS with the scope of setting up a CH4 monitoring network along the GrIS. The performance of the MOS is evaluated on the basis of simultaneous measurements using a cavity ring-down spectroscopy (CRDS) reference instrument for CH4 over a field calibration period of approximately 100 h. Results from the field calibration period show that CH4 concentrations measured with the MOS are in very good agreement with the reference CRDS. The absolute concentration difference between the MOS and the CRDS reference values within the measured concentration range of approximately 2–100 ppm CH4 was generally lower than 5 ppm CH4, while the relative concentration deviations between the MOS and the CRDS were generally below 10 %. The calculated root-mean-square error (RMSE) for the entire field calibration period was 1.69 ppm (n=37 140). The results confirm that low-cost and low-power MOSs can be effectively used for atmospheric CH4 measurements under stable water vapor conditions. The primary scientific importance of the study is that it provides a clear example of how the application of low-cost technology can enhance our future understanding on the climatic feedbacks from the cryosphere to the atmosphere.

scholarly journals Continuous methane concentration measurements at the Greenland Ice Sheet-atmosphere interface using a low-cost low-power metal oxide sensor system

2019 ◽  
Author(s):  
Christian Juncher Jørgensen ◽  
Jacob Mønster ◽  
Karsten Fuglsang ◽  
Jesper Riis Christiansen
Keyword(s):  
Metal Oxide ◽  
Low Power ◽  
Low Cost ◽  
Ice Sheet ◽  
Greenland Ice Sheet ◽  
Mean Bias Error ◽  
Concentration Difference ◽  
Calibration Period ◽  
Field Calibration ◽  
Metal Oxide Sensor

Abstract. In this paper, the performance of a low-cost and low-power methane (CH4) sensing system prototype based on a metal oxide sensor (MOS) sensitive to CH4 is tested in a natural CH4 emitting environment at the Greenland Ice sheet (GrIS). We investigate if the MOS could be used as a supplementary measurement technique for monitoring CH4 emissions from the GrIS with the scope of setting up a CH4 monitoring network along the GrIS. The performance of the MOS is evaluated on basis of parallel measurements using a CRDS reference instrument for v over a field calibration period of approximately 100 h. Results from the field calibration period show that CH4 concentrations measured with the MOS is in very good agreement with the reference CRDS. The absolute concentration difference between the MOS and the CRDS reference values within the measured concentration range of approximately 2–100 ppm CH4 were generally lower than 5 ppm CH4, while the relative concentration deviations between the MOS and the CRDS were generally below 10 %. Calculated mean bias error for the entire field calibration period was −0.05 ppm with a standard deviation of ± 1.69 ppm (n = 37 140). The results confirms that low-cost and low-power MOS can be effectively used for atmospheric CH4 measurements under stable water vapor conditions. The primary scientific importance of the study is that it provides a clear example on how the application of low cost technology can enhance our future understanding on the climatic feedbacks from the cryosphere to the atmosphere.

scholarly journals Sensitive and Low-Power Metal Oxide Gas Sensors with a Low-Cost Microelectromechanical Heater

ACS Omega ◽  
2021 ◽  
Author(s):  
Yulong Chen ◽  
Mingjie Li ◽  
Wenjun Yan ◽  
Xin Zhuang ◽  
Kar Wei Ng ◽  
...  
Keyword(s):  
Metal Oxide ◽  
Low Power ◽  
Gas Sensors ◽  
Low Cost ◽  
Metal Oxide Gas Sensors

scholarly journals A Gas Mixture Prediction Model Based on the Dynamic Response of a Metal-Oxide Sensor

Micromachines ◽  
2019 ◽  
Vol 10 (9) ◽  
pp. 598 ◽  
Author(s):  
Wei-Chih Wen ◽  
Ting-I Chou ◽  
Kea-Tiong Tang
Keyword(s):  
Dynamic Response ◽  
Metal Oxide ◽  
Low Cost ◽  
High Sensitivity ◽  
Temperature Changes ◽  
Concentration Estimation ◽  
Gas Identification ◽  
Different Characteristics ◽  
Metal Oxide Sensor ◽  
Different Gases

Metal-oxide (MOX) gas sensors are widely used for gas concentration estimation and gas identification due to their low cost, high sensitivity, and stability. However, MOX sensors have low selectivity to different gases, which leads to the problem of classification for mixtures and pure gases. In this study, a square wave was applied as the heater waveform to generate a dynamic response on the sensor. The information of the dynamic response, which includes different characteristics for different gases due to temperature changes, enhanced the selectivity of the MOX sensor. Moreover, a polynomial interaction term mixture model with a dynamic response is proposed to predict the concentration of the binary mixtures and pure gases. The proposed method improved the classification accuracy to 100%. Moreover, the relative error of quantification decreased to 1.4% for pure gases and 13.0% for mixtures.

scholarly journals An Approximation for Metal-Oxide Sensor Calibration for Air Quality Monitoring Using Multivariable Statistical Analysis

Sensors ◽  
2021 ◽  
Vol 21 (14) ◽  
pp. 4781
Author(s):  
Diego Sales-Lérida ◽  
Alfonso J. Bello ◽  
Alberto Sánchez-Alzola ◽  
Pedro Manuel Martínez-Jiménez
Keyword(s):  
Air Quality ◽  
Metal Oxide ◽  
Least Squares Method ◽  
Low Cost ◽  
Quality Monitoring ◽  
Sensor Calibration ◽  
Calibration Data ◽  
Air Quality Monitoring ◽  
Human Beings ◽  
Metal Oxide Sensor

Good air quality is essential for both human beings and the environment in general. The three most harmful air pollutants are nitrogen dioxide (NO2), ozone (O3) and particulate matter. Due to the high cost of monitoring stations, few examples of this type of infrastructure exist, and the use of low-cost sensors could help in air quality monitoring. The cost of metal-oxide sensors (MOS) is usually below EUR 10 and they maintain small dimensions, but their use in air quality monitoring is only valid through an exhaustive calibration process and subsequent precision analysis. We present an on-field calibration technique, based on the least squares method, to fit regression models for low-cost MOS sensors, one that has two main advantages: it can be easily applied by non-expert operators, and it can be used even with only a small amount of calibration data. In addition, the proposed method is adaptive, and the calibration can be refined as more data becomes available. We apply and evaluate the technique with a real dataset from a particular area in the south of Spain (Granada city). The evaluation results show that, despite the simplicity of the technique and the low quantity of data, the accuracy obtained with the low-cost MOS sensors is high enough to be used for air quality monitoring.

Novel Concept for the Formation of Sensitive, Selective, Rapidly Responding Conductometric Sensors

2010 ◽  
Vol 1253 ◽  
Author(s):  
James L Gole ◽  
Serdar Ozdemir
Keyword(s):  
Metal Oxide ◽  
Low Power ◽  
Selection Process ◽  
Low Cost ◽  
Electrical Contact ◽  
Sensor Arrays ◽  
Weak Acid ◽  
Sensor Technology ◽  
Temperature Drift ◽  
Novel Concept

AbstractRapidly responding, reversible, sensitive, and selective porous silicon-based (PS) gas sensors, operating at low power, are formed with a highly efficient electrical contact to a nanopore covered microporous array. Significant changes in sensor surface sensitivity can be correlated with the strong and weak acid-base (HSAB) character of the interacting gas analyte and the acidic nature of the PS surface so as to produce a dominant physisorption and create a range of highly selective surface coatings. This selection process dictates the application of nanostructured metal oxide and/or nanoparticle catalytic coatings, and provide for notably higher sensitivities which, in concert, form a basis for selectivity. Depositions which include AuxO, SnOx (Sn+2,+4) , CuxO ( Cu+1,+2), NiO(Ni+2) , nano-alumina, and titania, provide for the detection of gases including NO, NO2, CO, NH3, PH3, and H2S in an array-based format at the sub-ppm level. The value of this conductometric sensor technology results from a combination of (1) its sensitivity and short recovery time, (2) its operation at room temperature as well as at a single, readily accessible, temperature with an insensitivity to temperature drift, (3) its potential operation in a heat-sunk configuration allowing operation to a surface temperature of 80°C even in highly elevated temperature environments (in sharp contrast to metal oxide sensors), (4) its ease of coating with diversity of clearly mapped gas-selective materials for form sensor arrays, (5) its low cost of fabrication and operation, (6) its low power consumption, (7) its ease of rejuvenation following contamination, and (8) its ability to rapidly assess false positives using FFT techniques, operating the sensor in a pulsed gas mode.

Sign in / Sign up

Export Citation Format

Share Document