Measurement uncertainty, traceability and evaluation of test results in testing laboratories

2002 ◽  
Vol 13 (4) ◽  
pp. 565-572 ◽  
Author(s):  
G Beges ◽  
J Drnovsek ◽  
I Pusnik ◽  
J Bojkovski
2021 ◽  
Vol 854 (1) ◽  
pp. 012093
Author(s):  
Silvana Stajkovic ◽  
Dragan Vasilev ◽  
Mirjana Dimitrijevic ◽  
Nedjeljko Karabasil

Abstract Knowledge of the measurement uncertainty of test results is fundamentally important for laboratories, their customers and all parties using and interpreting these results. In conformity assessment, a measurement result is used to decide if an item of interest conforms to a specified requirement. Because of measurement uncertainty, there is always the risk of incorrectly deciding whether or not an item conforms to a specified requirement based on the measured value of a property of the item. Conformity assessment can be quite challenging when the entity measured is so close to the tolerance limits of the specification that its uncertainty, however estimated, critically affects decision-making. In such cases, different decision rules can be used to make statements of conformity. The aim of this paper is to provide a survey of methods for the evaluation of measurement uncertainty in testing, as well as to stress the need for appropriate estimation of measurement uncertainty. This paper also aims to assist testing laboratories in understanding the different decision rules used in conformity assessment and level of risk (such as false accept and false reject) associated with the decision rule employed.


Talanta ◽  
2018 ◽  
Vol 189 ◽  
pp. 666-674 ◽  
Author(s):  
Ilya Kuselman ◽  
Francesca R. Pennecchi ◽  
Ricardo J.N.B. da Silva ◽  
D. Brynn Hibbert ◽  
Elena Anchutina

Author(s):  
Maria Cristina Dijmarescu

Destructive and non-destructive testing of materials present a rapid expansion given by the increase in market demand caused by the desire to obtain an increasingly better quality of products. The continuous increase in quality demands leads directly to the need to implement and modernize the techniques, methods, and equipment used for quality control. Consequently, the need for product testing services has a rapid growth. This paper presents the strength and weaknesses of implementing IT tools for the estimation of the measurement uncertainty in testing laboratories and the impact of these tools on the economic part


2017 ◽  
Vol 22 (2) ◽  
pp. 83-89 ◽  
Author(s):  
Waldemar Korol ◽  
Jolanta Rubaj ◽  
Grażyna Bielecka ◽  
Sławomir Walczyński ◽  
Joanna Reszko-Zygmunt ◽  
...  

Author(s):  
Klaus Brun ◽  
Rainer Kurz

Field testing of gas turbine compressor packages requires the accurate determination of efficiency, capacity, head, power and fuel flow in sometimes less than ideal working environments. Nonetheless, field test results have significant implication for the compressor and gas turbine manufacturers and their customers. Economic considerations demand that the performance and efficiency of an installation are verified to assure a project’s return on investment. Thus, for the compressor and gas turbine manufacturers, as well as for the end-user, an accurate determination of the field performance is of vital interest. This paper describes an analytic method to predict the measurement uncertainty and, thus, the accuracy, of field test results for gas turbine driven compressors. Namely, a method is presented which can be employed to verify the validity of field test performance results. The equations governing the compressor and gas turbine performance uncertainties are rigorously derived and results are numerically compared to actual field test data. Typical field test measurement uncertainties are presented for different sets of instrumentation. Test parameters that correlate to the most significant influence on the performance uncertainties are identified and suggestions are provided on how to minimize their measurement errors. The effect of different equations of state on the calculated performance is also discussed. Results show that compressor efficiency uncertainties can be unacceptably high when some basic rules for accurate testing are violated. However, by following some simple measurement rules and maintaining commonality of the gas equations of state, the overall compressor package performance measurement uncertainty can be limited and meaningful results can be achieved.


Author(s):  
Nitin K. Mandavgade ◽  
Santosh B. Jaju ◽  
Ramesh R. Lakhe

The performance and maintenance of testing laboratories is a prime issue. The quality of coal test results not only depends on performance of individual results but it also depends on the performance of various tests in the same laboratory. Machine interference is a significant problem in many manufacturing system and testing equipment. The variation of results for testing equipment may be due to various factors which need to calculate the uncertainty of measurement to show the accuracy of the machine. In case of coal testing laboratory, the plant layout and surrounding environment affects the performance of the system. The machine interference comes under variable causes which may affect the result. This chapter proposes a methodology for constructing system performance measures, finding out the various factors responsible for variations in result. The chapter deals with estimation of machine interference existence using variable control chart approach for coal testing equipment. The analysis of results for such machine interference will be useful and significant for system designers and practitioners.


Author(s):  
Daniel Groepper ◽  
Matt Bower

Ethical dilemmas are commonly encountered by genetic counselors, whether in the clinical or laboratory setting. This chapter describes common ethical dilemmas, conflicts, and challenges encountered in genetic testing laboratories. These situations include genetic testing of minors for adult-onset conditions, prenatal testing, the ethical impacts of incidental findings and unexpected test results, and conflicts of interest. This chapter also explores the genetic counselor’s role in addressing ethical issues. Resources are provided for managing these ethical dilemmas within the laboratory.


Author(s):  
Rainer Kurz ◽  
Klaus Brun

Field testing of gas turbine or electric motor driven compressor packages requires the accurate determination of efficiency, capacity, head, or power consumption in sometimes less than ideal working environments. Nonetheless, field test results have significant implication for the compressor and gas turbine manufacturers and their customers. Economic considerations demand that the performance and efficiency of an installation are verified to assure the return on investment for the project. Thus, for the compressor and gas turbine manufacturers, as well as for the end-user, an accurate determination of the field performance is of vital interest. This paper discusses a method to determine the measurement uncertainty and, thus, the accuracy, of test results under the typical constraints of a site performance test, for compressors capable of variable speed operation. Namely, a method is presented which can be employed to verify the validity of field test performance results. Results are compared with actual field test results, using redundant methods. Typical field test measurement uncertainties are presented for different sets of instrumentation. The effect of different equations of state on the calculated performance is also discussed. Test parameters that correlate to the most significant influence on the performance uncertainties are identified and suggestions are provided on how to minimize their measurement errors. Results show that compressor efficiency uncertainties can be unacceptably high when some basic rules for accurate testing are violated. However, by following some simple measurement rules and maintaining commonality of the gas equations of state, the overall compressor package performance measurement uncertainty can be limited and meaningful results can be achieved.


2000 ◽  
Vol 123 (1) ◽  
pp. 62-69 ◽  
Author(s):  
K. Brun ◽  
R. Kurz

Field testing of gas turbine compressor packages requires the accurate determination of efficiency, capacity, head, power and fuel flow in sometimes less than ideal working environments. Nonetheless, field test results have significant implication for the compressor and gas turbine manufacturers and their customers. Economic considerations demand that the performance and efficiency of an installation are verified to assure a project?s return on investment. Thus, for the compressor and gas turbine manufacturers, as well as for the end-user, an accurate determination of the field performance is of vital interest. This paper describes an analytic method to predict the measurement uncertainty and, thus, the accuracy, of field test results for gas turbine driven compressors. Namely, a method is presented which can be employed to verify the validity of field test performance results. The equations governing the compressor and gas turbine performance uncertainties are rigorously derived and results are numerically compared to actual field test data. Typical field test measurement uncertainties are presented for different sets of instrumentation. Test parameters that correlate to the most significant influence on the performance uncertainties are identified and suggestions are provided on how to minimize their measurement errors. The effect of different equations of state on the calculated performance is also discussed. Results show that compressor efficiency uncertainties can be unacceptably high when some basic rules for accurate testing are violated. However, by following some simple measurement rules and maintaining commonality of the gas equations of state, the overall compressor package performance measurement uncertainty can be limited and meaningful results can be achieved.


Author(s):  
L. K. Baybolova ◽  
A. K. Khaimuldinova ◽  
Zh. B. Asirzhanova

This article provides insights into qualification testing, interlaboratory comparative testing, and qualification testing programs in testing laboratories that analyze the safety of meat and meat products. Samples with codes OK-MB- 21 were used as a model for interlaboratory comparisons. The uniformity and stability of the CC code was assessed in accordance with GOST R 50779.60-2017 “Statistical methods. Application in proficiency testing through interlaboratory testing ”. Seven laboratories participated in the proficiency testing program. The test preparation procedure was described and the test results determined whether each sample tested was satisfactory or questionable. Participants with unsatisfactory results are encouraged to identify the causes of the alarms, take corrective actions and document them, and identify and eliminate the causes of the unsatisfactory results.


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