Estimate the reading error introduced by ±half of the least count for instruments such as vernier calipers and micrometers.
读数误差约 ± 分度值/2。
| Item | Formula / Note | Source / Standard |
|---|---|---|
| Uncertainty from finite resolution | With half-width a = delta_x/2, a rectangular distribution gives u = a/sqrt(3) = delta_x/(2·sqrt(3)) | JCGM 100:2008, Guide to the Expression of Uncertainty in Measurement (GUM) |
| Rectangular distribution assumption | Readings are equally likely within ±delta_x/2, hence division by sqrt(3) | JCGM 100:2008, Guide to the Expression of Uncertainty in Measurement (GUM) |
| Definition of resolution | The smallest difference in indications that can be meaningfully distinguished | JCGM 200:2012, International Vocabulary of Metrology (VIM) |
| When resolution is inadequate | Replace or upgrade the equipment when the resolution component dominates | ISO/IEC 17025:2017, General requirements for the competence of testing and calibration laboratories |