Compute relative uncertainty u_rel = u/|x| as a dimensionless ratio for expressing measurement precision as a percentage.
输入标准不确定度 u 与测得值 x，求相对不确定度。
| Item | Formula / Note | Source / Standard |
|---|---|---|
| Relative standard uncertainty | u_rel = u / |y|, where y is the measured value | JCGM 100:2008, Guide to the Expression of Uncertainty in Measurement (GUM) |
| Dimensionless | The result is dimensionless and often given in percent or ppm | JCGM 100:2008, Guide to the Expression of Uncertainty in Measurement (GUM) |
| Relative expanded uncertainty | U_rel = U/|y| = k · u_rel | JCGM 100:2008, Guide to the Expression of Uncertainty in Measurement (GUM) |
| Use | Enables comparison of accuracy across measurements of different magnitude and units | JCGM 100:2008, Guide to the Expression of Uncertainty in Measurement (GUM) |