Photoacoustic detection of acetone in N2 and synthetic air using a high power UV LED
- The performance of a photoacoustic trace gas sensor for the detection of acetone in N2 and synthetic air is reported. The sensor system utilises an amplitude modulated UV LED. The light source has an emission maximum at 278 nm and a maximum CW output power of 300 mW according to the datasheet. Three different collimating and focusing approaches have been investigated to guide the highly divergent LED light into the acoustic resonator of the photoacoustic measurement cell. A 3D printed aluminium cell was designed to optimize light coupling by simultaneously minimizing the photoacoustic background signal generation. Hence, the diameter of the resonator was set to a comparable large diameter of 10 mm and the inner walls of the resonator were mirror polished. The additive manufacturing procedure allowed for integration of a spirally formed gas channel, enabling gas heating prior to detection. The sensor performance was investigated by measuring acetone in N2 and synthetic air at different concentrations. The UV LED current was set to 86 % of the maximum value according to the datasheet of the light source in order to increase the lifetime and thermal stability. An Allan-Werle deviation analysis validates a stable sensor performance. The limit of detection (LoD) was determined at a 3σ noise level with a 10 s lock-in amplifier time constant by sampling data points over 20 s with a data acquisition rate of 5 Hz. LoDs of 80.8 ppbV and 19.6 ppbV were obtained for acetone in N2 and synthetic air, respectively.
Author: | Stefan Weigl, Florian Feldmeier, Rudolf Bierl, Frank-Michael Matysik |
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DOI: | https://doi.org/10.1016/j.snb.2020.128109 |
Parent Title (English): | Sensors Actuators B Chemical |
Publisher: | Elsevier |
Document Type: | Article |
Language: | English |
Year of first Publication: | 2020 |
Release Date: | 2021/03/12 |
Tag: | Acetone breath analysis; Acetone detection; High power UV LED; Photoacoustic spectroscopy; UV LED collimation system |
Volume: | 316 |
Issue: | August |
Article Number: | 128109 |
First Page: | 1 |
Last Page: | 11 |
Note: | Corresponding author at: Sensorik-Applikationszentrum (SappZ) der Ostbayerischen Technischen Hochschule Regensburg |
Institutes: | Fakultät Angewandte Natur- und Kulturwissenschaften |
Fakultät Angewandte Natur- und Kulturwissenschaften / Sensorik-Applikationszentrum (SappZ) | |
Begutachtungsstatus: | peer-reviewed |
research focus: | Sensorik |
OpenAccess Publikationsweg: | Hybrid Open Access - OA-Veröffentlichung in einer Subskriptionszeitschrift/-medium |
Corresponding author der OTH Regensburg | |
Licence (German): | Creative Commons - CC BY-NC-ND - Namensnennung - Nicht kommerziell - Keine Bearbeitungen 4.0 International |