BS AU 50.1.1.2:2001 pdf free.Passenger car tyres-Methods for measuring rolling circumference-Loaded new tyres.
BS AU 50.1.1.2 1 Scope This International Standard specifies two methods for measuring, under loaded conditions, the roling circumference and revolutions per unit distance (kilometres) of new tyres for use on passenger cars. The first is a drum method that consists of loading a test tyre mounted on a free axle against a driven road wheel, or drum, of specified diameter. The second involves using a vehicle whose drive axle is equipped with the test tyres driven on a straight, paved road.
This International Standard is applicable to all passenger car tyres. However, the values obtained from the measurements are not intended to be used as benchmarks for performance or quality. 2 Normative reference
The following normative document contains provisions which, through reference in this text, constitute provisions of this International Standard. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply. However, parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent edition of the normative document indicated below. For undated references, the latest edition of the normative document referred to applies. Members of ISO and IEC maintain registers of currently valid International Standards.
ISO 4000-1, Passenger car tyres and rims – . Part 1: Tyres (metric series).
3 Terms and definitions For the purposes of this International Standard, the ollowing terms and definitins apply.
revolutions per unit distance number of tyre revolutions, and parts of revolutions, that occur when the (axle) centre of the tyre is moved a unit distance of exactly 1 km; the number of tyre revolutions per kilometre is calculated as one divided by the tyre rolling circumference (in mllimetres) multiplied by 106 rolling circumference of tyre Cr distance covered by the tyre during one complete revolution Drum method 4.1 Principle.A lest tyre mounted on a free axle is loaded against a driven road wheel (drum) of specified diameter. The value of the rolling circumference is determined for a specified speed, the tyre and drum revolutions are counted and used in the formula, and the formula then used to determine the lyre’s rolling circumference.BS AU 50.1.1.2 pdf download.