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S. Schemelter, R. Model, G. Wendt, M. Bär
NUMERICAL INVESTIGATION OF TEMPERATURE DISTRIBUTIONS IN LARGE STORAGE TANKS

Using storage tanks for commercial transactions, the precise determination of the quantity of the liquid stored in the tank is required. Whereas the identification of the actual volume is realized by measuring the filling height by level gauges, for mass calculations the mean temperature of the liquid has to be additionally known.

N. Almeida, E. Batista, E. Filipe, F. M. Smits, M. P. van der Beek
EURAMET INTERLABORATORY COMPARISON OF 1000 L PROVING TANK

In order to verify the agreement of results and procedures between eleven European National Metrology Institutes (NMIs) for large volume instruments, a EURAMET comparison “Inter-comparison of 1000 L proving tank”, was performed. This paper describes the transfer standard, the calibration methods and equations for the determination of the volume, the experimental conditions and the measurement results with the correspondent associated uncertainties. This comparison made it possible, within EURAMET, to have a comparison for large volumes. Before this comparison EURAMET comparisons where arranged in the µL range and volumes like 100 mL, 5 L and 20 L.

Young-Cheol Ha, Kyung-Am Park, Seung-Jun Lee, Jae-Young Her
DESIGN OF A LARGE-CAPACITY FLOW CALIBRATION/TEST FACILITY FOR NATURAL GAS FLOW METER

A new large gas flow calibration facility, which will be owned by Kogas (Korea Gas Corporation) and operated by Kogas and KRISS (Korea Research Institute of Standards and Science), has been designed. The facility employs the closed loop, master meter method. The flow range is 20-24 000 m3/h, the pressure range is 10-50 bara, and the expected calibration and measurement capability (CMC) is 0.22-0.24% for all pressure ranges.
As of June 2013, the design of the new calibration facility is almost completed, except for the detailed design of the circulation compressor unit and the heat exchanger. It is scheduled to be finished by the end of 2015.

Thomas Kegel, William Johansen
MONITORING THE REPEATABILITY AND REPRODUCIBILITY OF A NATURAL GAS CALIBRATION FACILITY

The high flow system of the Iowa natural gas facility has been in place for 14 years. A number of programs are maintained to monitor the random effects. Traditional control chart techniques have been adapted for the measurements of pressure, temperature, gas composition and flowrate. Turbine meter calibration standards have traditionally been monitored using ultrasonic check meters. A new low flow system has recently been installed that makes use of ultrasonic meters as both calibration and check meters. This paper will describe the development and interpretation of some monitoring techniques for the various flowrate standards.

Henry Abril, Luis E. García, Juan M. Ortiz, John F. Velosa
DEVELOPMENT A MOBILE LABORATORY FOR METROLOGICAL ASSURANCE OF QUALITY AND QUANTITY IN NATURAL GAS CUSTODY TRANSFER IN COLOMBIA

The relevance of providing traceability to gas quality and quantity in field increases every day. However, this task is expensive, generates risks related to equipment transport, demands adequate logistics and the required time to fulfill the measurement assurance process (calibration, confirmation and correction) may be long, causing disagree among agents involved in the natural gas custody transfer process. As a feasible alternative to provide traceability to the measurements of gas quality and quantity in field, International Gas Transmission Company (TGI S.A. ESP) and the Gas Technological Development Center (CDT de GAS), supported by COLCIENCIAS, planned and carried out the design and commissioning of a mobile laboratory integrating the facilities to operate as a stationary metrology laboratory and CMC conform to the requirements of the natural gas measurement processes.

I. Care, M. Arenas
ON THE IMPACT OF ANEMOMETER SIZE ON THE VELOCITY FIELD IN A CLOSED WIND TUNNEL

In the present paper, experimental and numerical investigations of the flow around different types and sizes of anemometers are presented and discussed. The measurements of the flow field at different distances upstream to the anemometer are performed with a laser Doppler Anemometer. The computational results are in rather good agreement with the experimental ones and show that anemometers may induce a strong distortion of the velocity field, even far upstream the anemometer.

A. Piccato, P. G. Spazzini, R. Malvano
FLOW FEATURES IN A RENEWED WIND TUNNEL

In the present paper, the preimlinary tests conducted about a renewed wind tunnel are described. The test rig was deeply reviewed during these last two years. The works were performed focussing on the aim of improving the metrological features of the device in view of its use within the definition of an airspeed standard. Measurements of maxium airspeed and flow fluctuation along the test chamber axis are presented here.

Woong Kang, Nguyen Doan Trang, Jae Sig Shim, Hee Soo Jang, Yong Moon Choi
EXPERIMENTAL AND NUMERICAL INVESTIGATIONS OF FACTORS EFFECT ON THE S-TYPE PITOT TUBE COEFFICIENTS

In the greenhouse gas emission monitoring from industrial stacks, S-type Pitot tube is the most commonly used to measure the stack gas velocity. Various factors such as Reynolds number, misalignment of installation angle can be additional error sources for the S-type Pitot tube coefficients due to harsh environments. In present study, wind tunnel experiments were conducted to examine the effects of various factors on the S-type Pitot tube coefficients. Numerical simulations were also used to understand flow phenomena around S-type Pitot tube when misalignment and distortion of geometry happen.

K. Mattiasson
KEY COMPARISONS AND THE ULTIMATE TRANSFER STANDARD

The Working Group for Fluid Flow (WGFF) (a part of CIPM) has established the key comparisons for measurement of flow and volume covering volume, water, oil and gas flow measurement. This paper discusses the methodology of key comparison performed within flow and volume measurement and present the ultimate transfer standard package consisting of two different measuring principles. This opens the possibility to obtain Youden plots to distinguish between uncertainty contribution from the transfer standards and the facility. By putting the main part of the work in choosing and characterizing the transfer standards and minimizing the paper work, future Key Comparisons will benefit.

Jos G. M. van der Grinten, Alex M. van der Spek
CONFORMITY ASSESSMENT USING MONTE CARLO METHODS

Conformity assessment is the activity to determine whether specified requirements relating to a product, process, system, person or body are fulfilled. Often measurements are used to show that the measurand is within (legal) tolerances. Currently analytical methods are available to test whether tolerances are met with a preset level of confidence, e.g. 95%. The test requires the availability of the overall measurement uncertainty and the statistical distribution of the measurand. In absence of better information this distribution is assumed to be Gaussian. The new point in this paper is that Monte Carlo methods can be applied directly to perform the conformity assessment. The reason is that the Monte Carlo process generates the cumulative distribution, whereby the (legal) tolerances can be compared directly. The advantage of this process is that the type of distribution does not need to be known and the (worst case) assumption of the distribution being Gaussian can be avoided. Consequently, for a Monte Carlo method the difference between tolerances and acceptance criteria is slightly smaller than for analytical methods. A test of the Monte Carlo method applied to a calibration of a high-pressure gasmeter meeting MID tolerances demonstrates the applicability of the method in practice.

Page 499 of 977 Results 4981 - 4990 of 9762