Erratum: On the precision and accuracy of the acoustic birefringence technique for stress evaluation

Abstract

published at Matéria (Rio de Janeiro) 27(3):e20220146:On page 2 where it was written: These statistical concepts and their use here are briefly reviewed in the following subsections [4]. Statistical errors: basic conceptsConsider a sample of N direct measurements of a variable x {x1, x2, ..., xN }, the standard estimate for the expected result of the measurement is […] If the number of measurements N is not sufficiently large (which is usually the case at the experiments carried out at IEN's ultrasonic laboratory), […] It should read:These statistical concepts and their use here are briefly reviewed in the following subsections [4, 5]. Statistical errors: basic conceptsThe result of the measurement of a quantity should be given by the best estimate of its expected value and the uncertainty associated with this estimate. The best estimate for the expected value of a quantity from a sample of N direct measurements of a variable x {x1, x2, ..., xN }, is the mean or average value of these measurements, and the uncertainty associated with this estimate is the standard deviation of this mean or average value.