| Title: |
Primary calibration for airborne infrasound utilizing the vertical gradient of the ambient pressure |
| Authors: |
Rust, Marvin; Kling, Christoph; Koch, Christian |
| Contributors: |
European Association of National Metrology Institutes |
| Source: |
Metrologia ; volume 60, issue 4, page 045001 ; ISSN 0026-1394 1681-7575 |
| Publisher Information: |
IOP Publishing |
| Publication Year: |
2023 |
| Description: |
The demand for reliable and traceable measurements of airborne infrasound has risen, one major application being the International Monitoring System run by the Comprehensive Nuclear-Test-Ban Treaty Organization. However, the current calibration methods do not sufficiently cover the infrasound frequency range. In this paper, we present a calibration method for microphones in this frequency range and its implementation as a measurement setup. The method is based on the vertical gradient of the ambient pressure as a stimulus. A DUT is subjected to an alternating pressure by periodically changing its altitude. The measurement setup realizes such a periodic altitude change by means of a vertically rotating disk and is capable of calibrating measurement microphones in a frequency range from 0.1 Hz to 5 Hz with a planned extension to 10 Hz. A measurement uncertainty of 0.07 dB at maximum could be realized. Particular attention was paid to the mechanics of the measurement setup to ensure that the DUT moves in a precisely determined orbit. We present example calibrations and an uncertainty budget for a Brüel & Kjær 4193 measurement microphone in the frequency range from 0.1 Hz to 5 Hz. Finally, we demonstrate the performance of the calibration method by comparing the acquired results to other calibration techniques showing an agreement better than 0.1 dB. |
| Document Type: |
article in journal/newspaper |
| Language: |
unknown |
| DOI: |
10.1088/1681-7575/acd941 |
| DOI: |
10.1088/1681-7575/acd941/pdf |
| Availability: |
https://doi.org/10.1088/1681-7575/acd941; https://iopscience.iop.org/article/10.1088/1681-7575/acd941; https://iopscience.iop.org/article/10.1088/1681-7575/acd941/pdf |
| Rights: |
http://creativecommons.org/licenses/by/4.0 ; https://iopscience.iop.org/info/page/text-and-data-mining |
| Accession Number: |
edsbas.D898EDF3 |
| Database: |
BASE |