INTERFEROMETRIC LINEAR LASER MEASURING SYSTEM CALIBRATION BY COMPARATIVE METHOD / IMPLEMENTAÇÃO E VALIDAÇÃO DE MÉTODO COMPARATIVO DE CALIBRAÇÃO DE SISTEMA DE MEDIÇÃO LINEAR POR INTERFEROMETRIA LASER

AUTOR(ES)
DATA DE PUBLICAÇÃO

2002

RESUMO

The present work aims at the implementation of a calibration method for interferometric linear laser measurement systems by comparison to another reference system. The proposed method is considered simpler than the calibration by components that is carried out today at Inmetro (National Institute of Metrology, Standardization and Industrial Quality) and, as demonstrated along this work, presents the metrological reliability and accuracy necessary for several applications of lasers in dimensional metrology. This approach will supply the metrological needs of several laboratories accredited by Inmetro and of the Brazilian industry in general, users of such measurement systems, regarding cost and time of calibration. The method implemented was based on international technical standards related to calibration and uncertainty calculation and used a reference system calibrated at Inmetro, with traceability to national standards, with the lowest uncertainties that could be achieved. The said method performs the calibration of a laser system by comparison to another through measurements of the displacement of the table where the optical prism rests. What is indeed analyzed is the difference of the measurements obtained by the two laser systems for the same table displacement. The differences were recorded for each displacement of 200 mm, in a total of 2,000 mm, their variation being from 0.027 µm to 0.690 µm. The whole procedure was repeated four times, in different days, with three measurements for each displacement. Their standard deviation varied from 0.009 µm to 0.098 µm while their expanded uncertainties varied from 0.109 µm to 0.306 µm depending on the value of the displacement. The calibration methodology, correction calculation, errors sources and measurement uncertainty calculations for the linear measurement laser systems comparison are presented in this dissertation.

ASSUNTO(S)

metrologia dimensional dimensional metrology laser interferometric sistema laser de medicao laser system laser interferometrico

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