Determination and evaluation of the uncertainty of the result of linear dimension measuring by contactless method

The work demonstrates the need to establish the reliability of measurement results based on the concept "evaluation of measurement uncertainty" as uncertainty calculation methods are implemented internationally. The paper purpose is the construction of model uncertainty assessment results of laboratory experiments on the example of linear dimensions of parts using an optical measuring device of direct assessment (horizontal comparator). In this paper, an example is given consistent presentation of evaluation expanded uncertainty of measurement results for the size of the trust details p = 0.95 using comparator IZA-2. In this example demonstrates the use of a new approach to data processing and presenting the measurement result, the skills to help professionals working in the field of measurement. In the application of new approaches to quality assessment measurements take into account the following basic principles: in many cases, the concept of systematic and random error are inseparable, so their separation does not meet the quality measurement; estimation bias severe requires formulating rules and regulations, they also have to be applied probabilistic assessment; Assessment of quality measurement should be carried out according to international rules, the same for all countries - participants of Metric Convention. The main task after the experiment is to assess the credibility of the results. For this purpose, the analysis of the components of uncertainty, uncertainty components evaluated by Type B: Standard uncertainty caused by the design of the comparator, assuming uniform of the distribution of possible values within certain boundaries u(D0 ) = 0.6928 mm; Standard uncertainty that caused an error reading impressions u(Dзчит ) = 0.2887mm, Standard uncertainty of the impact of temperature changesu(Dt ) = 3.3486mm . In light of all components defined combined uncertainty of type Buc В (D) = 3,4317 mm . For the estimation of measurement uncertainty, due to the contribution of random effects, a series of repeated measurements of the size of parts by the same operator under the same conditions. According to the rules of operation of the comparator fulfilled: preparation for work, installation of the measuring object and check its placement in the horizontal and vertical planes and performing a series of measurements. The results obtained are standard uncertainty of the measurement result by type A uA 0.6557 mm 0 ÷ = ø ö ç è æ D with the assumption of the normal distribution. The estimations expanded uncertainty of the measurement result for a given level of confidence p = 0.95 and an effective number of degrees of freedom n eff =1117 U (l) = 0,006846 mm . Compiled budget uncertainty in the measurement of linear dimensions of parts using the comparator YZA-2

measurement results reliability; uncertainty of measurement; standard uncertainty; total standard uncertainty (combined); expanded uncertainty; uncertainty of the type A; uncertainty of the type B