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1

Respiratory Disorders - Measuring Method and Equipment

Nitkiewicz S., Barański R., Kukwa A., Zając A.

Metrology and Measurement Systems

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2018

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Vol. 25, nr 1

187--202

EN

Respiratory disorders can occur from birth and accompany us throughout life. Very relevant and timely diagnosis of dysfunction is very important. Many currently performed examinations are not sufficient and do not give a full view of the cause of the disorder. In this paper the authors give several methods and pieces of equipment to do so. Furthermore, the proposed solution enables precise quantification of individual breaths, as well as their entire series. In addition to the above mentioned equipment, the authors present an example of software that works with the adopted solution. The considerations are illustrated with an example, along with calculations made using the authors’ software.

2

Absolutny pomiar bardzo małych prędkości przepływu gazu metodą fal cieplnych

Rachalski A.

Pomiary Automatyka Kontrola

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2013

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R. 59, nr 7

618--620

PL

Przedstawiono metodę absolutnego pomiaru prędkości przepływu gazu za pomocą fal cieplnych, w zakresie bardzo małych prędkości. Na podstawie rozwiązania analitycznego zjawiska propagacji fali cieplnej w płynącym gazie, prędkość przepływu wyznaczono metodą estymacji nieliniowej uprzednio zmierzonych przesunięć fazowych składowych harmonicznych fali w funkcji częstotliwości. Metoda umożliwia pomiar prędkości przepływu gazu rzędu kilku cm/s, bez uprzedniego wzorcowania czujnika.

EN

The phenomenon of thermal wave propagation in a flowing gas is described by the equation of energy conservation (Eq. 1). Kiełbasa [1] solved this equation using the Green's function technique and he obtained the phase shift for a linear periodic heat source (Eq. 9). This formula expresses that the wave velocity depends not only on the gas velocity but also on the thermal diffusion. If the condition of Eq. 11 is fulfilled, Eq. 10 becomes Eq. 12., so the thermal wave velocity is equal to the flow velocity, and the method can be considered as absolute. Otherwise, the probe needs to be calibrated. As can be seen from Eq. 10, the less flow velocity, the bigger difference between the flow velocity and the wave velocity. Fig. 2 shows that the lower limit of the flow velocity is about 30cm/s for air flow. Instead of a sinusoidal wave we apply a complex signal described by Eq. 12. After decomposing detectors signal into harmonics, we obtain the phase shift related to each harmonic. The phase shift obeys the system of equations (Eq. 14), where flow velocity VG and thermal diffusivity  are unknown parameters. The system can be solved by means of nonlinear estimation. Fig. 3 shows exemplary signals from the first and second detector. The results of estimation are presented in Fig. 4 and Tab. 1. The estimated values of both velocity and diffusivity are correct for the velocity equal to 7cm/s, while for the velocity of 50cm/s only the velocity value is correct. It is obvious that for this velocity the expression of Eq. 10 is insensitive to the thermal diffusivity, so the estimating procedure cannot find a proper value of the parameter. The presented method enables measurements of the gas flow velocity in the range of several cm/s without previous calibration of the probe. Further investigations will include searching an objective criterion of proper determination of the thermal diffusivity and improvement of the method accuracy.

3

Zastosowanie techniki termoanemometrycznej w badaniach modelowych nad rozprzestrzenianiem zanieczyszczeń gazowych

Moryń-Kucharczyk E., Jonas P., Mazur. O., Podolski M., Uruba V.

Systems : journal of transdisciplinary systems science

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2006

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Vol. 11, nr 1

247-254

EN

Simultaneous measurement of velocity and concentration in flow of two gases mixture is required at several wind tunnel experiments, e.g. modeling of pollutant dispersion. A thermoanemometer is a suitable tool for such measurements owing to it broad dynamic range for measurement of velocity and concentration fluctuations. The paper presents a measurement method by means of a special dual hot-wire probe (modification of the DANTEC t. 55P71) in a stream of the air/CO2 mixture. The in-house developed procedure of the simultaneous measurement of both the mean and the r.m.s. values of concentration and velocity was applied to investigation of a gaseous carbon dioxide round jet spreading into a collateral air flow. Performed experiments indicate that the applied measurement method might be useful for the turbulent diffusion investigations in complex conditions. They also confirm the usability of carbon dioxide as a tracer gas in modeling of gaseous pollutant spreading.

4

Struktura oprogramowania i możliwości metrologiczne sterowanego komputerowo wielokanałowego termoanemometrycznego systemu pomiarowego

Gawor M., Socha K.

Prace Instytutu Mechaniki Górotworu PAN

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2004

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Vol. 6, no. 3-4

195--204

PL

W pracy przedstawiono nowoczesne stanowisko pomiarowe umożliwiające pomiary termometryczne, anemometryczne oraz generację fal cieplnych. Opisano jego poszczególne elementy, ich właściwości i możliwości. Przedstawiono również sposób generacji fal cieplnych oraz problemy z uzyskaniem założonej częstotliwości fali. Zaprezentowano możliwości zastosowania systemu do wyznaczania prędkości przy pomocy funkcji korelacji wzajemnej. Opracowane oprogramowanie systemu pozwala użytkownikowi na łatwą realizację wielu algorytmów pomiaru prędkości i temperatury.

EN

An advanced measuring system presented in this work enables thermometer’s and anemometer’s measurements as well thermal waves generation. All parts of the system is described detaily with its teatures and abilities. The system was used to generate and measure manifold types of thermal waves with thermometer and thermoanemometer.

5

In memory of Professor Janusz Witold Elsner

Drobniak S., Jarża A.

Turbulence : international journal

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1999

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Vol. 5

7-76

EN

Janusz Witold EIsner was born on 29th of October 1928 in Warsaw. A graduate of the Technical University of Częstochowa (1958), he obtained his PhD and habilitation diplomas at the Technical University of Łódź in 1967 and 1977. In the period 1984-1990 he was Rector of the Technical University of Częstochowa (TUCz) and from 1977 Director of the Institute of Thermal Machinery at TUCz. Professor Elsner was a corresponding member of Polish Academy of Sciences and a member of European Mechanics Society (EUROMECH), chairman of the Mechanics Committee and a member of the Executive Council of the Thermodynamics and Combustion Committee of Polish Academy of Sciences. As a tribute to his scientific achievements he was awarded the title of Doctor Honoris Causa by the Polytechnic Institute in Mariupol (Ukraine) and by Technical University of Częstochowa. The long list of scientific achievements of Professor Elsner contains nearly 150 papers and supervision of 13 PhD Thesis, devoted to various aspects of turbulence dynamics and metrology. Professor Janusz Witold Elsner died on August 15, 1996, leaving in deep sorrow the scientific community.