IMEKO Event Proceedings

Page 807 of 851 Results 8061 - 8070 of 8504

L. Schinaia, A. Scorz, F. Orsini, S. A. Sciuto
Ultrasound image Uniformity Assessment by Means of Sparse Matrices: Algorithm Implementation and First Results

The current study is focused on an image segmentation algorithm for Uniformity Quality assessment in Diagnostic Ultrasounds.In particular a mathematical definition of the uniformity in ultrasound images is introducedand a split and merge algorithm performed on sparse matricesto measure uniformity is described. The algorithm is based on the Gray-Level Co-occurrence Matrices and the relativedescriptors,i.e. the Haralick features Entropy, Energy, Maximal CorrelationCoefficientand InformationMeasures of Correlation.Results on2 differentdatasetsof test images with different nonuniformities have been carried on. Several outcomesshow a goodsensitivity and agreement with the mean judgment by 7 human observers, i.e. differences are below 40% in most of the cases.On the basis of previousstudies, the latest developments and results are proposed and commented.

Stefan Johann Rupitsch, Bernhard Günther Zagar

We present the theory and some applications of the synthetic aperture focusing technique applied to single transducer ultrasonic data sets. In this technique a virtual source located at the geometrical focal point of the physical transducer is algorithmically generated and thus allows for tighter focusing over a geometrically larger scan volume. We present results from a structural test phantom (two copper wires) and a delaminated specimen.

Vahit Ciftci, Hakan Kaykisizli
UME Gas Flow Rate Measurement Systems and the New Wind Tunnel with LDA

National Metrology Institute of Turkey, UME, has partially completed the new gas flow velocity and gas flow rate measurement systems. In this article UME primary and secondary gas flow measurements systems for air at atmospheric conditions will be explained briefly.
In the new gas flow laboratories, velocity measurements and anemometer calibrations are realized with a 2D Laser Doppler Anemometer .Two dimensional velocity measurements up to 40 m/s can be done in two different tunnels that have dimensions 500 × 500 mm and 250 × 250 mm.
The wind tunnel system is constructed parallel to a gas flow measurement system. This turbine gas meter test rig is designed for a maximum flowrate of up to 19500 m³/h with an uncertainty less than 0,5 %. Another gas meter test rig for air at atmospheric conditions is designed and constructed to operate parallel with a sonic nozzle test rig. This system will be used for gas flowrate calibrations in the range of 50-5000 m³/h. Until the planned sonic nozzle test rig is added to this system, the uncertainty can be declared as 0,3 %. Primary standard Bell Prover and the low flow secondary standards Wet gas meter and Bubble Generators completes the traceability chain for gas flow at atmospheric conditions.

Vahit Çiftçi, Başak Akselli
UME Test Facilities for Oil Flow Measurement up to 300 m³/h

National Metrology Institute of Turkey, UME, has completed the new oil flow rate measurement systems. In this article, UME primary and secondary oil flow measurement systems will be described briefly. Oil flow laboratory was designed for the calibration, testing, and type approval of liquids other than water. It utilizes flow meters with the flow rates up to 300 m3/h and capable of testing of valves and pumps.
There are two 1 m3 and one 4 m3 oil reservoirs in the laboratory for different flow rate measurements with various type of oil. Three stainless steel pumps with the frequency converters can supply flow rates from 0 up to 300 m3/h. Pumps have capability of supplying required flow to calibration system directly or send oil to tower head tanks, which are located on the top of the tower, with capacities of 4, 2 and 1 m3. This system aims to decrease system measurements error due to pressure pulses created the tower is about 35 m from the laboratory floor level. Oil can be heated up to 80 °C by using heat exchangers.
There is three test lines on the oil flow rate measuring system as: Large Test Line (DN 300), Medium Test Line (DN 100) and Small Test Line (DN 50).
There are three weighting-time oil flow measurement systems and one of them has dead weight tester with 2.5 tons, 1 ton and 150 kg. DN 300, DN 100 and DN 50 ultrasonic type reference flow meters with the maximum capacities 250 m3/h are also placed on the systems. The uncertainties of all the reference flow meters are about 0.2 percent.
All the measuring lines were connected from one to others with the actuator valves and controlled by automation system.
There are two oil drainage system transfer pumps and packaged type oil separator with the level controllers. This system is used to clean the oil flow measurement systems.
Feeding, and controlling of the oil flow to the measuring lines and testing of the flow meters are being performed by the automation systems.

Vahit Çiftçi, Başak Akselli
UME Test Facilities for Water Flow Measurement up to 3 000 m³/h

National Metrology Institute of Turkey, UME, has completed new water flow rate measurement systems. In this article, UME primary and secondary water flow measurement systems will be described briefly. Water flow laboratory was designed for the calibration, testing, and type approval of water flow meters with the flow rates up to 3 000 m3/h and testing of the valves and pumps.
There is a 5 m × 20 m × 3 m water reservoir inside the laboratory, filled with soft water. Several stainless-steel pumps with the frequency converters exist in the system. The flow capacities are 20 to 1000 m3/h. Pumps are constructed either to feed the calibration system directly or through the constant pressure head tanks. The head tanks had capacities of 50, 15 and 5 m3 and located at the top of the tower. The height of the tower is 35 m from the laboratory floor level.
There are 5 Main test line on the water flow rate measuring system as: Large Test Line (DN -250, 400, 600), Medium Test Line (DN-200, 150, 125), Small Test Line-1 (DN-100, 80, 65,50), Small Test Line- 2 (DN-40, 32, 25, 20), Small Test Line- 3 (DN-15, 10, 5).
There are four weight-time water flow measurement systems as; 30 tons, 5 tons, 1 tone with dead weight tester and 20 kg. Estimated total expanded uncertainties of weighting systems are in 0.05 % range. There is also one volume-time flow measurement sub-system with the capacity up to 100 m3/h in the system. DN 400 and DN 250 Electromagnetic reference flow meters are located on the systems, with Capacities up to 2500 m3/h. DN 150, DN 80, DN 32 and DN 15 Turbine type flow meters with the minimum flow capacities 0.6 m3/h are also placed in the system. The uncertainties of all the reference flow meters are around 0.2 percent.
All the measuring lines, before the weighting systems were connected from one to others with the actuator valves and controlled by automation system.
There are two water-feeding pumps and tanks with the water temperature controllers, operating independently from the water reservoir that supplies hot, and cold water to the measuring line.

F. Arpino, L. Celenza, R. D’Alessio, M. Dell’Isola, G. Ficco, P. Vigo, A. Viola

One of the main issues in the natural gas (NG) transport networks management is represented by the Unaccounted for Gas (UAG). UAG is the quantity to be considered in the balance equation to take into account the unavoidable errors due to measurements and estimations. The resulting problem is twofold: on one hand fiscal and contractual, on the other hand the unavoidable pressure from the national authorities to reduce UAG. In this paper the authors analyse the UAG trends in natural gas (NG) transport networks and present: i) an investigation about UAG in international networks; ii) a statistical analysis of annual and monthly trends for UAG; iii) the analysis of UAG causes.

Harvey Padden
Uncertainties And Inter-Laboratory Comparisons of Dry Piston Gas Flow Provers

Dry piston provers are similar in nature to conventional mercury-sealed flow provers, with the exception that the viscosity of the gas forms the seal across a very small (< 10 µ) section. As a result, very small, portable provers can be produced. Calibrations can be performed with the accuracy, primacy and large dynamic range of the earier mercury-sealed provers, but far more rapidly. The transportable nature of these primary instruments also makes them very useful for the inexpensive, ongoing harmonization of laboratories.
Our latest uncertainty analysis shows a combined expanded uncertainty of less than 0.08 % over the range of 5 to 50,000 sccm. Although we made every effort to perform an accurate analysis, empirical verification of any uncertainty analysis is necessary. At this level, the only means of verification is through peer-to-peer inter laboratory comparisons.
As a result, we have performed informal comparisons of a single pair of provers with a number of national and private laboratories on three continents. We compared for reproducibility with respect to different national laboratories and over time, with transportation and between overlapping cellranges. In addition, and we compared newly manufactured provers with the original pair to establish reproducibility with manufacture. Typically, the provers exhibited discrepancies (within their specified range) of less than 0.1 % in comparison with critical flow venturis at NIST and NMIJ, with the possible exception of the 50,000 scm point. At the highest flow, the original prover exthibited a discrepancy of 0.15 % to 0.2 %. A second prover later showed a discrepancy of 0.035 %. We must conduct further investigations to determine the linearity of the design for flows above 30,000 sccm.
Here, we will present an introductory summary of the uncertainty analyses, details of the comparison methodology, data on potential experimental error sources (such as inventory volume), the comparative data, and the methods of data analyses used. We will also discuss our ongoing research at the lower limit of this design's useful range (approximately 1 sccm), where leakage is not necessarily constant and conventional viscosity may not apply.

Andreas Kamcke

Uncertainties in results caused by human factors of test persons are well known in the area of testing the speech quality of telephone connections. The presence of this kind of uncertainty components were already known when this test methodology was introduced. For elimination or reduction a new approach by using emotion detection is presented. First results and limits are given. In order to get a universal method standardization is urgently needed.

Jovan Bojkovski

This paper describes sources of uncertainties in the calibration of air temperature sensors. Air temperature sensors are calibrated within different calibration environments. Depending on the environment, typical sources of uncertainties are analyzed and evaluated. In total, three different air temperature sensors, two platinum resistance thermometers in combination with resistance bridge and one digital thermometer are calibrated from -7 °C to 70 °C and from -40 °C up to 100 °C, in two different calibration environments. The reference temperature was determined using thermistors and calibrated platinum resistance thermometers.

Peter Benkó, Rudolf Palencár

This contribution describes the procedure of evaluating the calibration of thermocouple by means of its comparison with the thermocouple standard. In the process of thermocouple calibration by means of comparison, the resulting uncertainty specified by applying the generalized procedure for evaluating the calibration of measuring devices with continuous scale. The advantage of this method of evaluation is the determination of uncertainties in the whole range of the calibration. The conclusion of this paper states the illustrated differencies between cases when covariances are into account or are not.

Page 807 of 851 Results 8061 - 8070 of 8504