Measurement of speed of sound in a gas-filled acoustic resonator

Determination of the specific toxic, harmful, or flammable gases concentration i.e. butane, cannot be done directly. It requires devices that can do this measurement without any direct contact between the gas and human (observer) i.e. gas sensors. These sensors are typically used in security systems or early warning system. This research is about design and development of a gas sensor based on acoustic resonance. The sensor that has been developed is acoustic resonator based sensor, with two speakers as the sources of acoustic vibrations. This sensor is made to work at its resonance frequency. Since the resonance frequency of acoustic resonator is influenced by the speed of sound in the acoustic resonator, and the speed of sound is influenced by the density and concentration of the gas in the acoustic resonator, the changing of gas concentrations will cause resonance frequency shifting of the acoustic resonator. So, by taking measurement of resonance frequency shifting of resonator, gas concentration can be determined. This research was conducted in four stages, the first stage is designing of acoustic resonator, the second stage is manufacturing and initial testing of the acoustic resonator, the third stage is conditioning stage to make acoustic resonator works at its resonance frequency automatically, and the final stage is the testing stage of acoustic resonator using butane. Based on the research conducted, it can be concluded that the acoustic resonator system can work accurately and precision to detect the changing of butane gas concentration. Absolute error and relative error are relatively small, the largest of absolute error is 7.69% and the largest relative error is 0.47%.

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Estimates of the difference between thermodynamic temperature and the International Temperature Scale of 1990 in the range 118 K to 303 K

Philosophical Transactions of The Royal Society A Mathematical Physical and Engineering Sciences ◽

10.1098/rsta.2015.0048 ◽

2016 ◽

Vol 374 (2064) ◽

pp. 20150048 ◽

Cited By ~ 20

Author(s):

R. Underwood ◽

M. de Podesta ◽

G. Sutton ◽

L. Stanger ◽

R. Rusby ◽

...

Keyword(s):

Speed Of Sound ◽

Temperature Scale ◽

Opposite Sign ◽

Thermodynamic Temperature ◽

Acoustic Resonator ◽

International Temperature Scale ◽

Acoustic Thermometry ◽

International Temperature ◽

The Difference

Using exceptionally accurate measurements of the speed of sound in argon, we have made estimates of the difference between thermodynamic temperature, T , and the temperature estimated using the International Temperature Scale of 1990, T 90 , in the range 118 K to 303 K. Thermodynamic temperature was estimated using the technique of relative primary acoustic thermometry in the NPL-Cranfield combined microwave and acoustic resonator. Our values of ( T − T 90 ) agree well with most recent estimates, but because we have taken data at closely spaced temperature intervals, the data reveal previously unseen detail. Most strikingly, we see undulations in ( T − T 90 ) below 273.16 K, and the discontinuity in the slope of ( T − T 90 ) at 273.16 K appears to have the opposite sign to that previously reported.

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Photoacoustic Excitation of the Interior Surface of an Acoustic Resonator for Speed of Sound Measurement

International Journal of Thermophysics ◽

10.1007/bf03344911 ◽

1998 ◽

Vol 19 (6) ◽

pp. 1595-1603 ◽

Cited By ~ 1

Author(s):

G. Benedetto ◽

R. M. Gavioso ◽

R. Spagnolo

Keyword(s):

Speed Of Sound ◽

Acoustic Resonator ◽

Interior Surface ◽

Sound Measurement

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Design and Development of Gas Sensor Based On Acoustic Resonance

KnE Engineering ◽

10.18502/keg.v1i1.482 ◽

2016 ◽

Vol 1 ◽

Author(s):

Melany Febrina

Keyword(s):

Resonance Frequency ◽

Gas Sensor ◽

Relative Error ◽

Speed Of Sound ◽

Acoustic Resonance ◽

Absolute Error ◽

Acoustic Resonator ◽

Design And Development ◽

Gas Concentration ◽

Frequency Shifting

Determination of the specific toxic, harmful, or flammable gases concentration i.e. butane, cannot be done directly. It requires devices that can do this measurement without any direct contact between the gas and human (observer) i.e. gas sensors. These sensors are typically used in security systems or early warning system. This research is about design and development of a gas sensor based on acoustic resonance. The sensor that has been developed is acoustic resonator based sensor, with two speakers as the sources of acoustic vibrations. This sensor is made to work at its resonance frequency. Since the resonance frequency of acoustic resonator is influenced by the speed of sound in the acoustic resonator, and the speed of sound is influenced by the density and concentration of the gas in the acoustic resonator, the changing of gas concentrations will cause resonance frequency shifting of the acoustic resonator. So, by taking measurement of resonance frequency shifting of resonator, gas concentration can be determined. This research was conducted in four stages, the first stage is designing of acoustic resonator, the second stage is manufacturing and initial testing of the acoustic resonator, the third stage is conditioning stage to make acoustic resonator works at its resonance frequency automatically, and the final stage is the testing stage of acoustic resonator using butane. Based on the research conducted, it can be concluded that the acoustic resonator system can work accurately and precision to detect the changing of butane gas concentration. Absolute error and relative error are relatively small, the largest of absolute error is 7.69% and the largest relative error is 0.47%.

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Response to “Oil-Based Gel Phantoms and the Speed of Sound”

Ultrasound in Medicine & Biology ◽

10.1016/j.ultrasmedbio.2020.07.012 ◽

2020 ◽

Vol 46 (11) ◽

pp. 3172

Author(s):

Natasha Alves ◽

Brian K. Courtney

Keyword(s):

Speed Of Sound

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PARAMETRIC OSCILLATIONS IN A LIQUID FILLED ACOUSTIC RESONATOR

Le Journal de Physique Colloques ◽

10.1051/jphyscol:1972660 ◽

1972 ◽

Vol 33 (C6) ◽

pp. C6-281-C6-284

Author(s):

P. J. KING

Keyword(s):

Acoustic Resonator ◽

Parametric Oscillations

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Low loss film bulk acoustic resonator in liquid environments

10.32469/10355/6083 ◽

2008 ◽

Author(s):

Sai Sumanth Pottigari

Keyword(s):

Acoustic Resonator ◽

Low Loss ◽

Film Bulk Acoustic Resonator ◽

Film Bulk

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AN IMPROVED ARMORED VEHICLE KRAZ “FIONA” NOISE SILENCER

Avtoshliakhovyk Ukrayiny ◽

10.33868/0365-8392-2019-1-257-21-26 ◽

2019 ◽

pp. 21-26

Author(s):

Volodymyr Fedorov ◽

Vasyl’ Yanovsky ◽

Dmytro Kovalshuk

Keyword(s):

Noise Reduction ◽

Speed Of Sound ◽

Acoustic Waves ◽

Noise Level ◽

Combustion Engine ◽

Environmental Aspect ◽

Exhaust Gases ◽

Ecological Requirements ◽

On The Road ◽

Armored Vehicle

Ecological requirements for cars grow from year to year, both in the world as a whole, and in Ukraine in particular. This is especially true of noise pollution. Additionally, noise reduction becomes relevant, taking into account the conduct of military operations during the last 5 years on the territory of Ukraine. The war has caused a special need for military vehicles for which masking properties are vital. Noise is a serious disincentive factor. Therefore, its reduction for a military vehicle, apart from the environmental aspect, is of a purely military nature, that is, it is extremely important. The car has many sources of noise there are many ways to deal with them. One of the most powerful source of noise is the sleeping bag. This kind of noise is reduced by means of silencers of noise. The vast majority of silencer data in the basis of its design has a reactive (or resonant) muffler. To calculate the jet silencer you must know the speed of sound in the sleeping bags. In order to increase the acoustic efficiency of reactive and resonant mufflers of exhaust gases noise of the ICE of cars, an experimental method was proposed for determining the speed of sound in the sleighs. Implementation of the method is carried out by measuring the attenuation of acoustic waves. The noise level of the bedrooms is measured without silencer and silencer. Based on the data obtained, the noise reduction performance of the residual is established. From the well-known formula, based on the calculation of the efficiency of the silencing of a jet muffler, a formula is obtained for calculating the speed of sound in the sleeping quays. In this formula, all parameters are known: the level of silencer efficiency, the noise level of the sleeping, the ratio of areas of cross sections of the muffler and the inlet pipe and the length of the muffler. The sound speed thus established can continue to be used not only for engines of the type for which measurements and calculations were made, but also with a certain approximation for some other types of engines. This method provides high accuracy for determining the required parameter. In the given work on the example of the armored car KrAZ “Fiona” the calculation of efficiency increase of the reactive silencer is made due to the above-mentioned method. Also, the projected decrease in the external noise level of the KrAZ Armored Vehicle “Fiona” is considered by determining the speed of sound in the recesses on the trunk cycle on the road with acceleration up to speed of 50 km/h (75 km/h) and the movement with this speed, as well as when driving at a speed of 45 km/h. Keywords: transport, armored car, internal combustion engine, exhaust, exhaust gases, noise, source, acoustic efficiency, acoustic efficiency, speed of sound, jet muffler.

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