Düşük maliyetli salınım tipi dijital yoğunluk ölçer geliştirilmesi

Öz

Düşük maliyetli, yüksek hassasiyetli ve kompakt yapıya sahip bir salınım tipi dijital yoğunluk ölçer geliştirilmiştir. Sistem; ‘U’ şeklinde bükülmüş cam tüp, piezoelektrik tahrik mekanizması, tüp sapmasını algılayan optik slot sensör ve rezonans frekansını ölçen Arduino tabanlı elektronik devreden oluşmaktadır. Cihazın çalışma prensibi, sıvının tüp içerisindeki kütlesine bağlı olarak rezonans frekansının değişmesine dayanmaktadır. Bu değişim, yoğunluk ile rezonans frekansı arasında doğrusal bir ilişki oluşturmakta; sistem, yoğunluğu bilinen referans çözeltiler (saf su ve farklı tuz konsantrasyonları) ile kalibre edilmiştir. Ölçümler sonucunda rezonans frekansı ile sıvı yoğunluğu arasındaki ilişkinin yüksek derecede lineer olduğu belirlenmiştir (R² = 0.9996). Yoğunluk değerleri virgülden sonra üç basamak hassasiyetle ve kararlı şekilde ölçülmüştür. Düşük maliyetli bileşenlerle üretilen bu prototip, laboratuvar ve endüstriyel kalite kontrol uygulamaları için ekonomik ve güvenilir bir alternatif sunmaktadır. Ayrıca sistemin taşınabilir yapısı, saha koşullarında hızlı ölçüm yapılmasına imkan tanımakta ve gelecekte sıcaklık kompanzasyonu gibi ek iyileştirmelerle daha geniş bir kullanım alanına uyarlanabileceğini göstermektedir.

Anahtar Kelimeler

• Sıvı yoğunluk ölçümü
• Salınım tipi sensör
• Doğal frekans
• Rezonans sensörü
• Titreşim tabanlı ölçüm

Development of low cost resonant type digital density meter

Öz

A low-cost, high-precision, and compact oscillation-type digital density meter has been developed. The device consists of a U-shaped glass tube, a piezoelectric actuation mechanism, an optical slot sensor for detecting tube deflection, and an Arduino-based electronic circuit for resonance frequency measurement. The working principle is based on the variation of resonance frequency as a function of the liquid mass inside the tube. This variation establishes a linear relationship between resonance frequency and liquid density. Calibration was performed using reference solutions with known densities (pure water and aqueous salt solutions of varying concentrations). Experimental results demonstrated a strong linear correlation between resonance frequency and density (R² = 0.9996). The system achieved stable density measurements with a precision of three decimal places. Owing to its low-cost components, the prototype provides an economical and reliable alternative for both laboratory and industrial quality control applications. In addition, its portable design enables rapid on-site measurements, and with further improvements such as temperature compensation, the system can be adapted for a broader range of applications.

Anahtar Kelimeler

• Liquid density measurement
• Oscillation type sensor
• Natural frequency
• Resonant sensor
• Vibration-based measurement

Kaynakça

1. F. Cuckow, A new method of high accuracy for the calibration of reference standard hydrometers, Journal of the Society of Chemical Industry, 68, 44-49, 1949. https://doi.org/10.1002/jctb.5000680203.
2. A. Rechberger, R. Amsüss, S. Rossegger, R. Breidler, and G. Steiner, High precision vibration-type densitometers based on pulsed excitation measurements, Sensors, 19, 1627, 2019. https://doi.org/10.3390/s19071627.
3. N. C. An, H. Jang, C. H. Kim, U. H. Ri, and H. C. Kim, Accuracy improvement of resonant sensor by an additional electrode in the measurement of liquid density and viscosity, Sensor Review, 44, 621-628, 2024. https://doi.org/ 10.1108/SR-04-2024-0289.
4. D. Xu, Y. Sun, W. Chen, J. Mu, and W. Peng, Development and experimental study of an experimental setup for an online vibrating tube liquid densitometer, Applied Sciences, 14, 9905, 2024. https://doi.org/10. 3390/app14219905.
5. X. Cheng, Development of resonant density meter and ıts application in tailings backfilling, Advances in Civil Engineering, 2021,1522639, 2021. https://doi.org/10.1155/ 2021/1522639.
6. L. Hnědkovský and I. Cibulka, An automated vibrating-tube densimeter for measurements of small density differences in dilute aqueous solutions, International Journal of Thermophysics, 25, 1135-1142, 2004. https://doi.org/10. 1023/B:IJOT.0000038505.88771.2e.
7. D. González-Salgado, J. Troncoso, and L. Romani, in Volume Properties: Liquids, Solutions and Vapours, ed. E. Wilhelm and T. Letcher, The Royal Society of Chemistry, pp. 100-114, 2014. https://doi.org/10.1039/9781782627043-00100.
8. C. Holcomb and S. L. Outcalt, A theoretically-based calibration and evaluation procedure for vibrating-tube densimeters, Fluid phase equilibria, 150, 815-827, 1998. https://doi.org/10.1016/S0378-3812(98)00362-8.

9. A. Furtado, E. Batista, I. Spohr, and E. Filipe, Measurement of density using oscillation-type density meters: calibration, traceability and uncertainties. Proceedings of the 14th International Congress of Metrology, Paris, France, 2009.
10. V. Semiconductors, Transmissive Optical Sensor with Phototransistor Output, Datasheet, 2009.
11. S. F. Barrett, Arduino I: Getting Started. Morgan & Claypool Publishers, San Rafael, CA, 2020.
12. B. Neff, F. Casset, A. Millet, V. Agache, and M. Colin, Piezoelectric actuated glass plate for liquid density and viscosity measurement, Micromachines, 11, 348, 2020. https://doi.org/10.3390/mi11040348.
13. L. Zhao, Y. Hu, T. Wang, J. Ding, X. Liu, Y. Zhao, Z. Jiang, A MEMS resonant sensor to measure fluid density and viscosity under flexural and torsional vibrating modes, Sensors, 16, 830, 2016. https://doi.org/10.3390 /s16060830.
14. Z. Li, Y. Gao, M. Chen, L. Lou, and H. Ren, An AlN piezoelectric micromachined ultrasonic transducer-based liquid density sensor, IEEE Transactions on Electron Devices, 70, 261-268, 2023. https://doi.org/10.1109/TED.20 22.3222662.
15. Huseynov, T. K., N. A. Abdulova, S. C. Abdullayeva, A. Y. Shirinova, and A. R. Hashimova, Investigation of the influence of the flow velocity of the measured liquid on the oscillation frequency of the resonator of a vibration-frequency density meter for the chemical industry, Int. Journal of Physics: Conference Series, vol. 2373, no. 8, p. 082024. IOP Publishing, 2022.
16. Sodium Chloride Water Solutions Density. Available: https://www.engineeringtoolbox.com/sodium-chloride-water-d_1187.html