All Title Author
Keywords Abstract


Ultrasonic Measurements of Temperature in Aqueous Solutions: Why and How

DOI: 10.1155/2011/156396

Full-Text   Cite this paper   Add to My Lib

Abstract:

The paper describes two different approaches to ultrasonic measurements of temperature in aqueous solutions. The first approach uses two narrowband ultrasonic transducers and support electronics that form an oscillating sensor which output frequency is related to the measured temperature. This low-cost sensor demonstrated sensitivity of about 40?Hz/K at the distance of 190?mm and the operating frequency of about 25?kHz. The second approach utilised pulse-echo mode at the centre frequency of 20?MHz. The reflector featured a cavity that was filled with deionised water. The ultrasound propagation delay in the cavity was related to the temperature in the solution. The experiments were conducted for deionised water, and solutions of sodium persulfate, sodium chloride, and acetic acid with concentrations up to 0.5?M. In the experiments (conducted within the temperature range from 15 to 30°C), we observed increases in the ultrasound velocity for increased temperatures and concentrations as was expected. Measurement results were compared with literature data for pure and seawater. It was concluded that ultrasonic measurements of temperature were conducted with the resolution well below 0.1?K for both methods. Advantages of ultrasonic temperature measurements over conventional thermometers were discussed. 1. Introduction to Ultrasonic Evaluation of Temperature Ultrasonic evaluation is used for various objects and media, especially when they are opaque and thus impenetrable by electromagnetic radiation. It involves excitation of ultrasonic waves by some transducers and reception of these waves after they have passed through the whole or a part of the object under evaluation. The measured decrease in the wave’s amplitude determines the ultrasound attenuation whilst the measured propagation delay specifies the ultrasound velocity. These parameters differ for various materials and also depend on the environmental conditions such as temperature (e.g., [1]). Ultrasonic spectroscopy is concerned with the ultrasound attenuation and velocity across a range of frequencies. Ultrasonic evaluation normally employs low intensity ultrasound, and can be considered non-invasive in most cases. However, the emitted energy needs to be constrained if it can cause changes to the object under evaluation. Ultrasonic evaluation is realised by using various arrangements for the wave excitation and reception (Figure 1) that have their specific advantages and limitations (Table 1). Table 1: Features of various ultrasonic evaluation methods. Figure 1: Experimental arrangements for various

References

[1]  G. W. C. Kaye and T. H. Laby, Tables of Physical and Chemical Constants, Longman, London, UK, 1986.
[2]  A. M. Mayer, “On an acoustic pyrometer,” Philosophical Magazine, vol. 45, pp. 18–22, 1873.
[3]  A. A. Fathimani and J. F. W. Bell, “A new resonant thermometer for nuclear reactor applications,” Journal of Physics E, vol. 11, no. 6, pp. 588–596, 1978.
[4]  S. F. Green, “An acoustic technique for rapid temperature distribution measurements,” Journal of the Acoustical Society of America, vol. 77, no. 2, pp. 759–763, 1985.
[5]  L. C. Lynnworth, “Industrial applications of ultrasound. A review. II. Measurements, tests, and process control using low intensity ultrasound,” IEEE Transactions on Sonics and Ultrasonics, vol. 54-22, no. 2, pp. 71–101, 1975.
[6]  “Thermocouple,” http://en.wikipedia.org/wiki/Thermocouple.
[7]  “Resistance thermometer,” http://en.wikipedia.org/wiki/Resistance_thermometer.
[8]  “Thermistor,” http://en.wikipedia.org/wiki/Thermistor.
[9]  “Silicon bandgap temperature sensor,” http://en.wikipedia.org/wiki/Silicon_bandgap_temperature_sensor.
[10]  R. M. Arthur, W. L. Straube, J. W. Trobaugh, and E. G. Moros, “Non-invasive estimation of hyperthermia temperatures with ultrasound,” International Journal of Hyperthermia, vol. 21, no. 6, pp. 589–600, 2005.
[11]  D. E. Yuhas, M. J. Mutton, J. R. Remiasz, and C. L. Vorrez, “Ultrasonic measurements of bore temperature in large caliber guns,” Review of Progress in Quantitative NDE, July 2008, http://imsysinc.com/downloads/QNDE%20NETS.pdf.
[12]  T. L. Liao, W. Y. Tsai, and C. F. Huang, “A new ultrasonic temperature measurement system for air conditioners in automobiles,” Measurement Science and Technology, vol. 15, no. 2, pp. 413–419, 2004.
[13]  A. N. Kalashnikov, K. L. Shafran, V. G. Ivchenko, R. E. Challis, and C. C. Perry, “In situ ultrasonic monitoring of aluminum ion hydrolysis in aqueous solutions: instrumentation, techniques, and comparisons to pH-metry,” IEEE Transactions on Instrumentation and Measurement, vol. 56, no. 4, pp. 1329–1339, 2007.
[14]  S. Alzebda and A. N. Kalashnikov, “Ultrasonic sensing of temperature of liquids using inexpensive narrowband piezoelectric transducers,” IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control, vol. 57, pp. 2704–2711, 2011.
[15]  A. N. Kalashnikov, V. Ivchenko, R. E. Challis, and A. K. Holmes, “Compensation for temperatre variation in ultrasonic chemical process onitoring,” in Proceedings of the IEEE Ultrasonics Symposium, pp. 1151–1154, September 2005.
[16]  “Sodium chloride,” http://resource.npl.co.uk/acoustics/techguides/soundseawater/.
[17]  A. N. Kalashnikov, V. G. Ivchenko, R. E. Challis, and B. R. Hayes-Gill, “High-accuracy data acquisition architectures for ultrasonic imaging,” IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control, vol. 54, no. 8, pp. 1596–1605, 2007.
[18]  “Sodium persulfate,” http://en.wikipedia.org/wiki/Sodium_persulfate.
[19]  V. A. Del Grosso and C. W. Mader, “Speed of sound in pure water,” Journal of the Acoustical Society of America, vol. 52, no. 5, pp. 1442–1446, 1972.
[20]  A. N. Kalashnikov and R. E. Challis, “Errors and uncertainties in the measurement of ultrasonic wave attenuation and phase velocity,” IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control, vol. 52, no. 10, pp. 1754–1768, 2005.
[21]  “Seawater,” http://en.wikipedia.org/wiki/Seawater.
[22]  G. S. K. Wong and S. M. Zhu, “Speed of sound in seawater as a function of salinity, temperature, and pressure,” Journal of the Acoustical Society of America, vol. 97, no. 3, pp. 1732–1736, 1995.
[23]  “Speed of sound in sea-water,” http://resource.npl.co.uk/acoustics/techguides/soundseawater/.
[24]  J. R. Lovett, “Merged sea-water sound speed equations,” Journal of the Acoustical Society of America, vol. 63, no. 6, pp. 1713–1718, 1978.
[25]  “Acetic acid,” http://en.wikipedia.org/wiki/Acetic acid. Publications of the present authors are available for anonymous download on ftp://128.243.76.5/PUBLIC DISK/ak1/index.htm.

Full-Text

comments powered by Disqus