F1ANNEX VIIIConditions governing the testing of vehicles with inertia (overrun) braking systems
2.SYMBOLS AND DEFINITIONS
2.4.
Symbols for hydraulic-transmission braking systems (see diagram 8 in Appendix 1)
2.4.1.
- ih
reduction ratio between travel of the coupling head and travel of the piston in master cylinder
2.4.2.
- ig
reduction ratio between travel of the actuation point of the cylinders and the brake-shoe centre lift
2.4.3.
- FRz
surface area of piston of one wheel cylinder for drum brake(s); for disc brake(s), sum of the surface area of the caliper piston(s) on one side of the disc
2.4.4.
- FHz
surface area of piston in master cylinder
2.4.5.
- p
hydraulic pressure in brake cylinder
2.4.6.
- pO
retraction pressure in brake cylinder; that is, in the graph M = ƒ (p), the value of the pressure p at the point of intersection of the extrapolation of this function with the abscissa (see diagram 7 in Appendix 1)
2.4.7.
- ρ′
characteristic of the brake defined by:
Substituted by Commission Directive 98/12/EC of 27 January 1998 adapting to technical progress Council Directive 71/320/EEC on the approximation of the laws of the Member States relating to the braking devices of certain categories of motor vehicles and their trailers (Text with EEA relevance).