Fully Integrated Photoacoustic NO2 Sensor for Sub-ppb Level Measurement.
Sensors (Basel)
; 20(5)2020 Feb 26.
Article
em En
| MEDLINE
| ID: mdl-32110962
ABSTRACT
A fully integrated photoacoustic nitrogen dioxide (NO2) sensor is developed and demonstrated. In this sensor, an embedded photoacoustic cell was manufactured by using an up-to-date 3D printing technique. A blue laser diode was used as a light source for excitation of photoacoustic wave in the photoacoustic cell. The photoacoustic wave is detected by a sensitive microelectromechanical system (MEMS) microphone. Homemade circuits are integrated into the sensor for laser diode driving and signal processing. The sensor was calibrated by using a chemiluminescence NO-NO2-NOX gas analyzer. And the performance of this sensor was evaluated. The linear relationship between photoacoustic signals and NO2 concentrations was verified in a range of below 202 ppb. The limit of detection was determined to 0.86 ppb with an integration time of 1 s. The corresponding normalized noise equivalent absorption was 2.0 × 10-8 cm-1âWâHz-1/2. The stability and the optimal integration time were evaluated with an Allan deviation analysis, from which a detection limit of 0.25 ppb at the optimal integration time of 240 s was obtained. The sensor was used to measure outdoor air and the results agree with that obtained from the NO-NO2-NOX gas analyzer. The low-cost and portable photoacoustic NO2 sensor has a potential application for atmospheric NO2 monitoring.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Revista:
Sensors (Basel)
Ano de publicação:
2020
Tipo de documento:
Article