A low-cost ultrasonic absorption spectrometer mainly using off-the-shelf parts

Published

March 11, 2025

Author(s)

Michelle Crouse, Malgorzata Musial, Jason Widegren, Jacob Pawlik, Bryan Bosworth, Nathan Orloff, Aaron Hagerstrom, Angela Stelson, Robert Lirette

Abstract

Ultrasonic absorption spectroscopy can probe intermolecular interactions that inform research into chemical engineering and pharmaceutical manufacturing processes. The only commercial ultrasonic spectrometer costs over one hundred thousand dollars, putting it out of reach for many institutions. We designed an inexpensive ultrasonic absorption spectrometer comprised of off-the-shelf components and parts from a rapid prototyping service. We employed the through-transmission method for quantifying absorption, using thirty-one pulse measurements at varying distances. These measurements significantly improved absorption metrology accuracy compared to the fixed path technique and the pulse-echo method, which rely on only two measurements. We measured pure water to correct for diffraction effects and used repeated water measurements to propagate the uncertainty. We measured salt solutions and cellulose to validate the spectrometer, comparing the data to results obtained from a commercial spectrometer. The results were well within the margin of error for both devices. Notably, from these measurements, we observed a relaxation peak near 1 MHz in scandium sulfate, which was reported once before using a resonator method of spectroscopy. Our system offers an inexpensive alternative to a commercial ultrasonic absorption spectrometer accessible to university researchers and students.

Proceedings Title

Proceedings of Meetings on Acoustics

Volume

55

Issue

1

Conference Dates

November 19-21, 2024

Conference Location

Virtual, CO, US

Conference Title

187th Meeting of the Acoustical Society of America

Pub Type

Conferences

Download Paper

https://doi.org/10.1121/2.0002003

Local Download

Keywords

Ultrasonic absorption, Ultrasound, Acoustics

Citation

Crouse, M. , Musial, M. , Widegren, J. , Pawlik, J. , Bosworth, B. , Orloff, N. , Hagerstrom, A. , Stelson, A. and Lirette, R. (2025), A low-cost ultrasonic absorption spectrometer mainly using off-the-shelf parts, Proceedings of Meetings on Acoustics, Virtual, CO, US, [online], https://doi.org/10.1121/2.0002003, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=959248 (Accessed October 16, 2025)