scholarly journals Diaphragmless shock tube for primary dynamic calibration of pressure meters

ACTA IMEKO ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 310
Author(s):  
A. Svete ◽  
J. Kutin
Keyword(s):  
Shock Tube ◽  
Input Signal ◽  
Measurement Model ◽  
Step Change ◽  
Dynamic Calibration ◽  
Shock Formation ◽  
Expanded Uncertainty ◽  
Relative Expanded Uncertainty ◽  
Pressure Step ◽  
Diaphragmless Shock Tube

In conventional shock tubes with a diaphragm many effects related to the burst of the diaphragm can influence the shock formation and thus prevent an ideal pressure step change predicted by the shock tube measurement model being generated. This paper presents a newly developed diaphragmless shock tube, in which a diaphragm is replaced with a quick-acting pneumatic valve. The developed shock tube has a capability to generate pressure steps calculable from its measurement model with a relative expanded uncertainty of less than 0.025, which can be used as the input signal in primary calibrations of pressure meters.

A New-Conception, Electromagnetically Controlled, Diaphragmless Shock Tube

2003 ◽  
Author(s):  
Giovanni Ferrara ◽  
Lorenzo Ferrari ◽  
Maurizio De Lucia
Keyword(s):  
Shock Wave ◽  
Mach Number ◽  
Shock Tube ◽  
Test Time ◽  
Shock Formation ◽  
Test Results ◽  
Diaphragmless Shock Tube ◽  
Two Factors ◽  
University Of Florence ◽  
Contact Sensors

A new conception, electro-magnetically controlled, diaphragmless shock tube was realized and tested in the laboratories of University of Florence. A piston separates the co-axial driver and driven sections. The piston is kept in position by a force of an electromagnet acting on an iron disc linked to its rod. In order to obtain very short opening time, light materials were tested for moving devices: aluminum, ergal, titanium and iron. Opening time was measured using contact sensors. Several different dimensionless driven section lengths were tested by changing the driven section length and by reducing the driven section diameter. The influence of the two factors on shock presence and shock formation was analyzed separately. Tests were carried out for driver-to-driven pressure ratios of up to 22, obtaining shock waves at Mach number of up to 1.70 with a difference from the theoretical value for a straight shock tube of 9%. A configuration for increasing the useful test time after the shock passage is also proposed and tested. The system realized is simple, easy-to-use, quite cheap and can be a very useful way of obtaining a reproducible shock wave. The shock tube details and the test results are reported below.

Estimation of uncertainty in olfactometry

2009 ◽  
Vol 59 (7) ◽  
pp. 1409-1413 ◽  
Author(s):  
T. Higuchi
Keyword(s):  
Measurement Uncertainty ◽  
Interlaboratory Comparison ◽  
Collaborative Study ◽  
Estimation Procedure ◽  
Measurement Model ◽  
Standard Uncertainty ◽  
Expanded Uncertainty ◽  
Collaborative Test ◽  
Measurement Results ◽  
Estimation Of Uncertainty

Estimation of uncertainty in odour measurement is essential to the interpretation of the measurement results. The fundamental procedure for the estimation of measurement uncertainty comprises the specification of the measurement process, expression of the measurement model and all influences, evaluation of the standard uncertainty of each component, calculation of the combined standard uncertainty, determination of a coverage factor, calculation of the expanded uncertainty and reporting. Collaborative study such as interlaboratory comparison of olfactometry yields performance indicators of the measurement method including repeatability and reproducibility. Therefore, the use of collaborative test results for measurement uncertainty estimation according to ISO/TS 21748 and ISO 20988 is effective and reasonable. Measurement uncertainty of the triangular odour bag method was estimated using interlaboratory comparison data from 2003 to 2007 on the basis of the simplest model of statistical analysis, and the expanded uncertainty of odour index ranged between 3.1 and 6.7. On the basis of the establishment of the estimation procedure for uncertainty, a coherent interpretation method for the measurement results will be proposed and more effective and practical quality control of olfactometry will be available.

Investigation of vibration effect on dynamic calibration of pressure sensors based on shock tube system

Measurement ◽  
2020 ◽  
Vol 149 ◽  
pp. 107015 ◽  
Author(s):  
Kuan Diao ◽  
Zhenjian Yao ◽  
Zhongyu Wang ◽  
Xiaojun Liu ◽  
Chenchen Wang ◽  
...  
Keyword(s):  
Shock Tube ◽  
Pressure Sensors ◽  
Dynamic Calibration ◽  
Tube System ◽  
Vibration Effect

Shock formation distance in a pressure driven shock tube

1976 ◽  
Vol 19 (12) ◽  
pp. 1885 ◽  
Author(s):  
E. M. Rothkopf ◽  
W. Low
Keyword(s):  
Shock Tube ◽  
Shock Formation ◽  
Pressure Driven

Dynamic characterisation of pressure transducers using shock tube methods

2019 ◽  
Vol 42 (4) ◽  
pp. 743-748
Author(s):  
Andy J Knott ◽  
Ian A Robinson
Keyword(s):  
Dynamic Response ◽  
Shock Tube ◽  
Significant Variation ◽  
Pressure Transducer ◽  
Ideal Gas ◽  
Pressure Transducers ◽  
Pressure Step ◽  
Instantaneous Pressure

This paper describes the characterisation of the dynamic response of a range of pressure transducer systems. The transducers were subjected to virtually instantaneous pressure step inputs in the National Physical Laboratory’s shock tube facilities. The magnitudes of these pressure steps were derived from ideal gas theory, with prior commissioning tests having been performed to demonstrate the theory’s validity in this application. The results demonstrate a significant variation in response obtained from various combinations of transducer, instrumentation settings, and mounting arrangement.

Development of a Large Diameter Diaphragmless Shock Tube for Gas-Dynamic Laser Studies

2007 ◽  
Vol 566 ◽  
pp. 9-14 ◽  
Author(s):  
I. da S. Rego ◽  
K.N. Sato ◽  
S. Kugimiya ◽  
T. Aoki ◽  
Y. Miyoshi ◽  
...  
Keyword(s):  
Shock Waves ◽  
Shock Tube ◽  
Large Diameter ◽  
Gaseous Mixtures ◽  
Gas Dynamic ◽  
Diaphragmless Shock Tube ◽  
Good Accordance ◽  
Basic Characteristics ◽  
And Performance

This paper reports on the design and performance of a large diameter diaphragmless shock tube that has been recently developed in order to experimentally study various basic characteristics of the gas-dynamic laser (GDL). The main engineering element of the shock tube is a diaphragm-like sliding piston (in place of a rupturing diaphragm) by which normal shock waves are formed. The role of such a structure in generating repeatable shock waves is discussed. The shock tube performs in good accordance with the simple shock tube theory, as has been verified so far by experiments with some conventional lasing gases (gaseous mixtures of CO2 and N2 and those diluted with an excess of He) at shock wave Mach numbers ranging from 1 to 5. Recent results of the stagnation conditions achieved in the shock tube with application to GDL experiments are included as well.

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