Paragraph 2 MPEsF1
The MPE, positive or negative in mm, between two non-consecutive scale marks is (a + bL), where:
— L is the value of the length rounded up to the next whole metre; and
— a and b are given in Table 1 below.
When a terminal interval is bounded by a surface, the MPE for any distance beginning at this point is increased by the value c given in Table 1.
Table 1
| Accuracy Class | a(mm) | b | c(mm) |
|---|---|---|---|
| I | 0.1 | 0.1 | 0.1 |
| II | 0.3 | 0.2 | 0.2 |
| III | 0.6 | 0.4 | 0.3 |
The MPE for the length between consecutive scale marks, and the maximum permissible difference between two consecutive intervals, are given in Table 2 below.
Table 2
| Length i of the interval | MPE or difference in millimetres according to accuracy class | ||
|---|---|---|---|
| I | II | III | |
| i ≤ 1 mm | 0.1 | 0.2 | 0.3 |
| 1 mm < i ≤ 1 cm | 0.2 | 0.4 | 0.6 |
Where a rule is of the folding type, the jointing shall be such as not to cause any errors, supplementary to those above, exceeding: 0.3 mm for Class II, and 0.5 mm for Class III.
Annotations
Textual amendments
- F1
Schs. 1A-1K inserted (E.W.S.) (31.12.2020) by The Product Safety and Metrology etc. (Amendment etc.) (EU Exit) Regulations 2019 (S.I. 2019/696), reg. 1, Sch. 27 para. 49 (with Sch. 27 para. 50(a)) (as amended by S.I. 2020/676, regs. 1(1), 2); 2020 c. 1, Sch. 5 para. 1(1)