The accuracy of precision instrument measurement in industrial inspection

Abstract

Data were collected in two plants relative to the accuracy of precision instrument usage. Two hundred employees of the first plant gave their best judgment of the dimension of their particular work sample after obtaining 5 readings using their accustomed precision instrument, e.g., vernier micrometer, depth micrometer, etc. In the second plant, 45 more highly skilled tool-room workers were tested in the use of the vernier micrometer, and results from the two plants were compared. (So-called "true" dimensions were established by ultra-precision instruments in combination with Johansen blocks.) The authors report the following: Precision instrument usage is less accurate than formerly assumed; in this study no significant correlation between accuracy of micrometer readings and age or amount of experience was found, but the accuracy of measurement was directly related to gross size of the measured part. (PsycInfo Database Record (c) 2025 APA, all rights reserved)