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Comparison of the characteristics of small commercial NDIR CO2 sensor models and development of a portable CO2 measurement device.

Yasuda T, Yonemura S, Tani A - Sensors (Basel) (2012)

Bottom Line: When the correction was applied to the sensors, the accuracy of measurements improved significantly in the case of the K30 and AN100 units.In particular, in the case of K30 the relative RMS error decreased from 24% to 4%.This indicates that acceptable accuracy can be realized using the calibration method developed in this study.

View Article: PubMed Central - PubMed

Affiliation: Plant and Environmental Sciences, Department of Environmental Health Science, University of Shizuoka, Shizuoka Japan. p09402@u-shizuoka-ken.ac.jp

ABSTRACT
Many sensors have to be used simultaneously for multipoint carbon dioxide (CO(2)) observation. All the sensors should be calibrated in advance, but this is a time-consuming process. To seek a simplified calibration method, we used four commercial CO(2) sensor models and characterized their output tendencies against ambient temperature and length of use, in addition to offset characteristics. We used four samples of standard gas with different CO(2) concentrations (0, 407, 1,110, and 1,810 ppm). The outputs of K30 and AN100 models showed linear relationships with temperature and length of use. Calibration coefficients for sensor models were determined using the data from three individual sensors of the same model to minimize the relative RMS error. When the correction was applied to the sensors, the accuracy of measurements improved significantly in the case of the K30 and AN100 units. In particular, in the case of K30 the relative RMS error decreased from 24% to 4%. Hence, we have chosen K30 for developing a portable CO(2) measurement device (10 × 10 × 15 cm, 900 g). Data of CO(2) concentration, measurement time and location, temperature, humidity, and atmospheric pressure can be recorded onto a Secure Digital (SD) memory card. The CO(2) concentration in a high-school lecture room was monitored with this device. The CO(2) data, when corrected for simultaneously measured temperature, water vapor partial pressure, and atmospheric pressure, showed a good agreement with the data measured by a highly accurate CO(2) analyzer, LI-6262. This indicates that acceptable accuracy can be realized using the calibration method developed in this study.

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Relationship between temperature and CTCday in the case of K30 (n = 3).
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f4-sensors-12-03641: Relationship between temperature and CTCday in the case of K30 (n = 3).

Mentions: CTCday was calculated using Equation (8) for each measurement at a different temperature and for different length of use. CTCday was plotted against temperature and length of use, and the relationships between them were investigated. Figure 4 shows the relationship between CTCday for K30 and T. CTCday increased linearly with increasing T, and the values of the slope were not greatly different among data obtained for different lengths of use. Linear relationships were not observed in the case of AN100 and S100.


Comparison of the characteristics of small commercial NDIR CO2 sensor models and development of a portable CO2 measurement device.

Yasuda T, Yonemura S, Tani A - Sensors (Basel) (2012)

Relationship between temperature and CTCday in the case of K30 (n = 3).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3376595&req=5

f4-sensors-12-03641: Relationship between temperature and CTCday in the case of K30 (n = 3).
Mentions: CTCday was calculated using Equation (8) for each measurement at a different temperature and for different length of use. CTCday was plotted against temperature and length of use, and the relationships between them were investigated. Figure 4 shows the relationship between CTCday for K30 and T. CTCday increased linearly with increasing T, and the values of the slope were not greatly different among data obtained for different lengths of use. Linear relationships were not observed in the case of AN100 and S100.

Bottom Line: When the correction was applied to the sensors, the accuracy of measurements improved significantly in the case of the K30 and AN100 units.In particular, in the case of K30 the relative RMS error decreased from 24% to 4%.This indicates that acceptable accuracy can be realized using the calibration method developed in this study.

View Article: PubMed Central - PubMed

Affiliation: Plant and Environmental Sciences, Department of Environmental Health Science, University of Shizuoka, Shizuoka Japan. p09402@u-shizuoka-ken.ac.jp

ABSTRACT
Many sensors have to be used simultaneously for multipoint carbon dioxide (CO(2)) observation. All the sensors should be calibrated in advance, but this is a time-consuming process. To seek a simplified calibration method, we used four commercial CO(2) sensor models and characterized their output tendencies against ambient temperature and length of use, in addition to offset characteristics. We used four samples of standard gas with different CO(2) concentrations (0, 407, 1,110, and 1,810 ppm). The outputs of K30 and AN100 models showed linear relationships with temperature and length of use. Calibration coefficients for sensor models were determined using the data from three individual sensors of the same model to minimize the relative RMS error. When the correction was applied to the sensors, the accuracy of measurements improved significantly in the case of the K30 and AN100 units. In particular, in the case of K30 the relative RMS error decreased from 24% to 4%. Hence, we have chosen K30 for developing a portable CO(2) measurement device (10 × 10 × 15 cm, 900 g). Data of CO(2) concentration, measurement time and location, temperature, humidity, and atmospheric pressure can be recorded onto a Secure Digital (SD) memory card. The CO(2) concentration in a high-school lecture room was monitored with this device. The CO(2) data, when corrected for simultaneously measured temperature, water vapor partial pressure, and atmospheric pressure, showed a good agreement with the data measured by a highly accurate CO(2) analyzer, LI-6262. This indicates that acceptable accuracy can be realized using the calibration method developed in this study.

Show MeSH