scholarly journals Accuracy of single-jet and multi-jet water meters under the influence of the filling process in intermittently operated pipe networks

2017 ◽  
Vol 18 (2) ◽  
pp. 679-687 ◽  
Author(s):  
David Walter ◽  
Miran Mastaller ◽  
Philipp Klingel
Keyword(s):  
Measurement Error ◽  
Measurement Errors ◽  
Distribution Systems ◽  
Air Flow ◽  
Pipe Network ◽  
Filling Process ◽  
Two Phase ◽  
Single Jet ◽  
Water Meters ◽  
The Impact

Abstract In many areas of the world water distribution systems are operated intermittently. The alternate filling and emptying of the pipe network leads to effects, which have negative impacts on water meter accuracy. For example, air that is present in the pipe network due to the emptying process must exit the network during the subsequent filling process. A part of this air is discharged through service connections and, thus, through water meters. In this paper, a study is presented in which the measurement error of single-jet and multi-jet water meters due to the filling process of an empty pipe is investigated experimentally. From the start of air flow to the steady-state flow of water, several causes of measurement errors can be distinguished, such as pure air flow, the impact of the water front on the impeller, the existence of two-phase flow or unsteady flow conditions. For both meter types, it has been discovered that the measurement error is mainly caused by the air flow. The experimental results show that up to 93% of the air volume in the pipe is registered by the water meters. Based on these results, an approach for estimating the measurement error for both meter types is presented.

scholarly journals Metrological performance of single-jet water meters over time

2018 ◽  
Vol 13 (5) ◽  
pp. 1
Author(s):  
Carmen Virginia Palau ◽  
Juan Manzano ◽  
Iban Balbastre Peralta ◽  
Benito Moreira de Azevedo ◽  
Guilherme Vieira do Bomfim
Keyword(s):  
Measurement Error ◽  
Water Consumption ◽  
Operating Conditions ◽  
Economic Losses ◽  
Flow Rates ◽  
Metrological Operation ◽  
Operation Period ◽  
Single Jet ◽  
Water Meters ◽  
Over Time

To maintain quality measurement of water consumption, it is necessary to know the metrology of single-jet water meters over time. Knowing the accuracy of these instruments over time allows establishing a metrological operation period for different flow rates. This will aid water companies to optimize management and reduce economic losses due to unaccounted water consumption. This study analyzed the influence of time on the measurement error of single-jet water meters to evaluate the deterioration of the equipment and, with that, launch the metrological operation period. According to standards 8316 and 4064 of the International Organization for Standardization (ISO), 808 meters of metrological Class B were evaluated in six water supplies, with age ranges of 3.7 to 16.4 years of use. The measurement error was estimated by comparing the volume measured in a calibrated tank with the volume registered by the meters at flow rates of 30, 120, 750 and 1,500 L h-1. The metrological operation period of the meters was obtained for each flow rate by the relation between error of measurement and time of use (simple linear regression). According to the results, the majority of the equipment presents increasing under-registration errors over time, more pronounced at low flow rates and with less favorable operating conditions. The metrological operation period for flow rates of 30, 120, 750 and 1,500 L h-1 is estimated at approximately 3, 8, 14 and 13 years. This operation period combined with consumption patterns of users will establish the best time to replace the meters.

Measurement Error: A Primer for Macroeconomists

2020 ◽  
Author(s):  
Simon van Norden
Keyword(s):  
Measurement Error ◽  
Measurement Errors ◽  
Forecast Errors ◽  
National Accounts ◽  
Simple Arithmetic ◽  
Multiple Data ◽  
Realistic Assessment ◽  
Market Production ◽  
Considerable Controversy ◽  
The Impact

Most applied researchers in macroeconomics who work with official macroeconomic statistics (such as those found in the National Accounts, the Balance of Payments, national government budgets, labor force statistics, etc.) treat data as immutable rather than subject to measurement error and revision. Some of this error may be caused by disagreement or confusion about what should be measured. Some may be due to the practical challenges of producing timely, accurate, and precise estimates. The economic importance of measurement error may be accentuated by simple arithmetic transformations of the data, or by more complex but still common transformations to remove seasonal or other fluctuations. As a result, measurement error is seemingly omnipresent in macroeconomics. Even the most widely used measures such as Gross Domestic Products (GDP) are acknowledged to be poor measures of aggregate welfare as they omit leisure and non-market production activity and fail to consider intertemporal issues related to the sustainability of economic activity. But even modest attempts to improve GDP estimates can generate considerable controversy in practice. Common statistical approaches to allow for measurement errors, including most factor models, rely on assumptions that are at odds with common economic assumptions which imply that measurement errors in published aggregate series should behave much like forecast errors. Fortunately, recent research has shown how multiple data releases may be combined in a flexible way to give improved estimates of the underlying quantities. Increasingly, the challenge for macroeconomists is to recognize the impact that measurement error may have on their analysis and to condition their policy advice on a realistic assessment of the quality of their available information.

scholarly journals Selected Aspects of Crisis Management with the Use of Unmanned Aerial Vehicles (UAV) on the Example of a Traffic Disaster

2021 ◽  
Vol 58 (2) ◽  
pp. 140-152
Author(s):  
Wiesław Jaszczur ◽  
Szymon Łukasik
Keyword(s):  
Measurement Error ◽  
Unmanned Aerial Vehicles ◽  
Crisis Management ◽  
Measurement Errors ◽  
The Other ◽  
Research Approach ◽  
Aerial Vehicles ◽  
Other Hand ◽  
The Impact ◽  
Modern Technologies

Purpose: The theoretical aim of this study was to present the impact of modern technologies on the improvement of the effectiveness of process activ- ities (documenting) at the site of a communication disaster. On the other hand, the utilitarian goal was to present the improvement of the organization of documenting a mass incident with the use of drones and photogrammetry tools. Design and methods: As part of the exercise consisting of a simulation of a communication disaster, the activities were documented using the func - tionality of unmanned aerial vehicles which interact with an IT system (Pix4D application). The characteristic drone models which can be used in the monitoring of a disaster site were presented. The discussed research approach describes the methods used to perform drone flights and to what extent the photogrammetric method of processing digital images obtained from drones was used. The issue of field measurements (control points, control lines), the purpose of which was to determine the accuracy of mapping and matching to the coordinate system, was discussed. Results: As part of the research, images were captured and taken with the use of UAVs and IT systems, which were collated and compared with the results of measurements from the visual inspection of the disaster site, performed in a traditional manner by the representatives of the procedural entity. A comparative analysis of the collected research material leading to a comparison of the work results captured by means of the traditional procedural forms with the methods and techniques of modern technologies (drone with the Pix4D Cloud application) allows for the following conclusions to be drawn. For short measuring sections (up to 15 meters), the measurement accuracy of the two methods differs by about 1.5%. For longer measuring sections (up to 100 m), the measurement error is approx. 2.3%. Conclusions: In case of the UAV method and the application Pix4D Cloud, the sources of measurement errors should be seen in the accuracy of rendering of the details of the model (the quality of imaging) and the ability to use this application. On the other hand, when using the police method, in which the measurement trolley is the measuring tool, the sources of error should be seen in the uneven terrain, the obstacles in the terrain, and the measurement error of the tool itself (the trolley). The innovation of the project to use UAVs certainly gains importance especially in a terrain with limited accessibility, i.e. in hilly and mountainous terrain, at road intersections or forks. Keywords: communication disaster, modern technologies, crisis management Article type: preliminary report

scholarly journals Global diversification: Evidence from corporate operating performance

2007 ◽  
Vol 4 (4) ◽  
pp. 228-242 ◽  
Author(s):  
Mai Iskandar-Datta ◽  
Robyn McLaughlin
Keyword(s):  
Measurement Error ◽  
Measurement Errors ◽  
Operating Performance ◽  
Diversification Discount ◽  
Empirical Results ◽  
Excess Value ◽  
Performance Examining ◽  
The Impact ◽  
Global Diversification

This study casts light on the impact of the decision to diversify globally on the firm’s operating performance. Examining operating performance enables us to circumvent the measurement errors associated with excess value that is used to measure the diversification discount/premium. Our central empirical results for a sample of firms that chose to diversify globally reveal that sample firms, in spite of exhibiting a diversification discount, significantly outperform their domestic counterparts following the diversification. Our findings imply that global diversification does not result in misallocation of investment resources. The fact that our firms exhibit the diversification discount and yet outperform their domestic counterparts confirms previous studies’ conclusions that the diversification discount is most likely an artifact of measurement error

A Simulation Analysis of Interactions among Errors in Costing Systems

2007 ◽  
Vol 82 (4) ◽  
pp. 939-962 ◽  
Author(s):  
Eva Labro ◽  
Mario Vanhoucke
Keyword(s):  
Measurement Error ◽  
Measurement Errors ◽  
Cost Allocation ◽  
Simulation Analysis ◽  
Stage Ii ◽  
Accounting Systems ◽  
Activity Cost ◽  
Costing System ◽  
Product Costs ◽  
The Impact

Cost accounting systems provide accurate costs only under stringent conditions. However, we know little about the nature, level, and bias of costing errors. This paper reports the results of a simulation study of two-stage cost allocation systems that provide the following main insights: (1) partial improvement in the costing system usually increases the overall accuracy of reported product costs except in specific cases identified in this paper where errors have an offsetting effect, most notably when there is aggregation error in the activity cost pools and measurement error in the resource drivers; (2) the impact of Stage II costing errors on overall accuracy is stronger than that of Stage I errors, so system refinements should focus on Stage II; and (3) the presence of aggregation and measurement errors usually results in relatively more products being under- than over-costed, with large amounts of over-costing for a few “big-ticket” (in dollar terms) products, and small amounts of under-costing for a larger number of less expensive products.

scholarly journals Influencing Factor and Error Analysis of Operating Capacitor Voltage Transformer Harmonic Measurement

2021 ◽  
Vol 2121 (1) ◽  
pp. 012013
Author(s):  
Yan Zhang ◽  
Huajia Wang ◽  
Danwen Yu ◽  
Liu Yang ◽  
Wenjun Cao ◽  
...  
Keyword(s):  
Measurement Error ◽  
Measurement Errors ◽  
Influencing Factor ◽  
Screening Method ◽  
Error Characteristic ◽  
Characteristic Analysis ◽  
Voltage Transformer ◽  
Capacitor Voltage ◽  
The Impact ◽  
Harmonic Measurement

Abstract With the increasing demands of power quality monitoring and management, the problem of harmonic measurement error caused by the widespread operation of capacitor voltage transformers (CVT) in high-voltage power grids has been unavoidable. This paper analyses the influence of environmental factors on harmonic measurement error of CVT, and proposes a new method for analysing the harmonic measurement errors of operating CVT, which explains the unstable phenomenon of CVT measurement errors based on field comparison test, and provides a progressing screening method of effective analysis data. the CVT harmonic error characteristic analysis method proposed in this paper considers the impact of field installation conditions, electromagnetic environment, and other actual operating environment, which can reflect the actual harmonic error characteristics of CVT in field operation. A CVT harmonic measurement system is established based on the proposed method. The validation and effectiveness of the proposed method is illustrated on a field measurements of 1000kV CVT in Shandong Province.

Features of accumulation of amounts of measurement error

2017 ◽  
Vol 928 (10) ◽  
pp. 58-63 ◽  
Author(s):  
V.I. Salnikov
Keyword(s):  
Measurement Error ◽  
Confidence Interval ◽  
Normal Distribution ◽  
Confidence Level ◽  
Measurement Errors ◽  
Truncated Normal Distribution ◽  
Truncated Normal ◽  
The Law ◽  
Normal Law

The initial subject for study are consistent sums of the measurement errors. It is assumed that the latter are subject to the normal law, but with the limitation on the value of the marginal error Δpred = 2m. It is known that each amount ni corresponding to a confidence interval, which provides the value of the sum, is equal to zero. The paradox is that the probability of such an event is zero; therefore, it is impossible to determine the value ni of where the sum becomes zero. The article proposes to consider the event consisting in the fact that some amount of error will change value within 2m limits with a confidence level of 0,954. Within the group all the sums have a limit error. These tolerances are proposed to use for the discrepancies in geodesy instead of 2m*SQL(ni). The concept of “the law of the truncated normal distribution with Δpred = 2m” is suggested to be introduced.

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