Experimental verification of a method for quasi-continuous monitoring of the resonance frequency of a quartz tuning fork based photoacoustic detector
Georgii K. Raspopin1, Viktor V. Nikolaev1, Alexei V. Borisov1, Yury V. Kistenev2
1Laboratory of Ecophotonics, Tomsk State University, 634050, Tomsk, Russia
2Laboratory of Laser Molecular Imaging and Machine Learning, Tomsk State University, 634050, Tomsk, Russia
Abstract
The use of high‑Q quartz tuning fork (QTF) as highly sensitive detectors in gas phase photo-acoustic spectroscopy is associated with the need for continuous calibration of their mechanical resonance frequency (fres) due to its dependence on the temperature, humidity, and composition of the gas sample being studied. The approaches used today for adjusting the resonant frequency of the QTF require complex switching circuits or interrupting the process of photo‑acoustic measurements. To overcome these limitations, a method for quasi‑continuous monitoring of fres was proposed and numerically investigated in [1]. The principle is based on measuring the fres of the reference QTF using an acoustic excitation source and, based on the obtained value, adjusting the fmod of the optical radiation source in real time.
In the present work, an experimental verification of the proposed method’s effectiveness was carried out using the example of studying the fres dependence of two acoustically isolated quartz fork resonators with a nominal resonant frequency of fres = 32768 Hz, obtained within the frequency range of 32740-32770 Hz at temperature values T = {20; 25; 30; 37}°C. The results demonstrate that, by measuring the resonance frequency of a reference QTF and knowing the calibration conversion coefficients that relate the temperature dependencies of the reference and measurement QTFs, it is possible to determine the mechanical resonance frequency of the measurement QTF. Thus, is enables the fmod of the optical source to be matched to the fres of the photo-acoustic detector without interrupting the measurement process.
The work was performed according to the Government research assignment for TSU, project FSWM-2025-0038
[1]. Борисов А.В., Николаев В.В., Кистенев Ю.В. Метод квазинепрерывного контроля частоты акустического резонанса фотоакустического детектора на основе кварцевого резонатора. Известия высших учебных заведений. Физика. – 2025. – Т. 68. – No. 11. – С. 68-74. – DOI: 10.17223/00213411/68/11/8.
Speaker
Raspopin Georgii Konstantinovich
Laboratory of Ecophotonics, Tomsk State University, 634050, Tomsk, Russia
Russia
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