[F1CHAPTER 1E+W+SMaterial measures of length
Textual Amendments
F1Schs. 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)
The relevant essential requirements of Schedule 1A, the specific requirements of this Schedule and the conformity assessment procedures listed in this chapter, apply to material measures of length defined below. However, the requirement for the supply of a copy of declarations of conformity may be interpreted as applying to a batch or consignment rather than each individual instrument.
SPECIFIC REQUIREMENTS
Reference ConditionsE+W+S
1.1. For tapes of length equal to or greater than 5 metres, the maximum permissible errors (MPEs) are to be met when a tractive force of fifty newtons or other force values as specified by the manufacturer and marked on the tape accordingly, or in the case of rigid or semi-rigid measures no tractive force is needed, is applied.
1.2. The reference temperature is 20 °C unless otherwise specified by the manufacturer and marked on the measure accordingly.E+W+S
MPEsE+W+S
2. 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.
MaterialsE+W+S
3.1. Materials used for material measures shall be such that length variations due to temperature excursions up to ± 8 °C about the reference temperature do not exceed the MPE.
3.2. Measures made from material whose dimensions may alter materially when subjected to a wide range of relative humidity, may only be included in Classes II or III.E+W+S
MarkingsE+W+S
4. The nominal value shall be marked on the measure. Millimetre scales shall be numbered every centimetre and measures with a scale interval greater than 2 cm shall have all scale marks numbered.
CONFORMITY ASSESSMENT The conformity assessment procedures specified in the modules in Schedule 1B applicable to material measures of length that the manufacturer can choose between are:
(a)F1;
(b)D1;
(c)B and D;
(d)H; or
(e)G.]