# Council Regulation (EEC) No 3821/85 of 20 December 1985 on recording equipment in road transport, Division 2.2: Measurement of speed

Extent: E+W+S+N.I.

024 The recording equipment shall measure speed from 0 to 220 km/h.
025 To ensure a maximum tolerance on speed displayed of ± 6 km/h in use, and taking into account:
a ± 2 km/h tolerance for input variations (tyre variations, …),
a ± 1 km/h tolerance in measurements made during installation or periodic inspections,
the recording equipment shall, for speeds between 20 and 180 km/h, and for characteristic coefficients of the vehicle between 4 000 and 25 000 imp/km, measure the speed with a tolerance of ± 1 km/h (at constant speed).
025a The speed shall be measured correctly within the normal tolerances within 2 seconds of the end of a speed change when the speed has changed at a rate up to 2 m/s 2 .
026 Speed measurement shall have a resolution better than or equal to 1 km/h.

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Source: https://www.legislation.gov.uk/eur/1985/3821/annex/2/division/III/division/2/division/2.2 (the official version)
Page: https://openlegislation.uk/eu-regulation-1985-3821/annex-2/division-III/division-2/division-2.2
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.