scholarly journals Uncertainty of measurement -Important parameter for product conformity assessment

Author(s):  
Gina Mihaela SICOE ◽  

The measurements are widely used to ensure the quality of products. It is known that the measurement process is influenced by many factors which lead to measurement errors. The uncertainty of measurement is an essential parameter because the expression of the results accompanied by uncertainty offers more confidence in the results. The research presented in this article focuses on methods forcalculating uncertainty and explaining the rules for making decisions when we use uncertainty. Two case studies are presented, one for dimensional measurements and the other for the estimation of the uncertainty of Vickers hardness measurement for one material, steel OLC15, in order to establish the relevance of the results and quality assessment. The results obtained on several measurements and the uncertainties of measurement associated are presented in the article and a discussion of the results is undertaken.

2002 ◽  
Vol 1 (2) ◽  
Author(s):  
Paulo Roberto Guimarães Couto ◽  
Ilse Maria Guilhermino Lemos

The result of a measurement serves as a parameter in a variety of applications, such as: the sale of products; the inspection of materials in relation to specifications/ limits set by a standard; providing support for a judicial ruling; improving the specific quality of products; estimating profitability and making comparisons with a view to mutual recognition between metrology laboratories and systems. The aim of this work is to demonstrate the relevance and applications of the ISO GUM 95 in the fuel analyses conducted by the LABCOM at the EQ/UFRJ, presenting results tables and discussions. The paper further discusses the strategic importance of metrological reliability of measurement results and of the actions of a laboratory within the context of the science of metrology in Brazil.


2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Idah Mkwezalamba ◽  
Chimuleke R. Y. Munthali ◽  
Edward Missanjo

Sclerocarya birrea(A. Rich.) Hochst. is a multipurpose fruit tree which is very useful in providing food security and meeting nutritional and economic needs. This study was conducted to assess eighteen provenances ofSclerocarya birreaplanted in Mangochi, Malawi. The trial was assessed for fruit traits at fifteen years of age. There were significant (P<0.001) variations among the provenances in number of fruits, fruit weight, pulp weight, seed weight, fruit length, and diameter. Magunde provenance from Mozambique had the highest mean number of fruits, 2196 ± 200. Mangochi and Moamba provenances from Malawi and Mozambique were the most outstanding in the other parameters measured attaining the mean fruit weight of 20.89 ± 0.25 g and 25.67 ± 0.67 g, pulp weight of 25.70 ± 0.08 g and 21.55 ± 0.83 g, seed weight of 4.81 ± 0.35 g and 4.12 ± 0.18 g, fruit length of 2.61 ± 0.14 cm and 2.33 ± 0.07 cm, and fruit diameter of 2.33 ± 0.15 cm and 1.97 ± 0.08 cm, respectively. There was no significant (P>0.05) correlation between number of fruits and the other fruit traits. However, there were significant (P<0.05) and strong positive relationships between fruit weight and pulp weight (r=0.987) and fruit length and diameter (r=0.775). This suggests that fruit weight can be used indirectly for selection of pulp. Further studies should investigate fruit taste quality of products from the fruits.


2008 ◽  
Vol 38 (3) ◽  
pp. 631-636 ◽  
Author(s):  
C. W. Woodall ◽  
J. A. Westfall

Accurately measuring the dimensions of coarse woody debris (CWD) is critical for ensuring the quality of CWD estimates and, hence, for accurately estimating forest ecosystem attributes (e.g., CWD carbon stocks). To improve the quality of CWD dimensional measurements, the distribution of taper (ratio of change in diameter and length) and relative size (RS; ratio of length and large-end diameter) of CWD pieces across the US were examined. Additionally, an outlier identification technique was developed by predicting the median and interquartile range of taper and RS as a function of large-end diameter, length, and decay class by major species group. The median CWD taper and RS across the US were 1.268 cm/m and 0.280 m/cm, respectively, with notable outliers. The taper and RS outlier identification protocol rapidly identified nearly 3% of study observations as outliers. Incorporation of CWD taper and RS outlier identification protocols into field data recorders may allow efficient control of measurement errors during field inventories.


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