This International Standard specifies test methods for type approval testing of controls on trailers for overrun brakes.1) The test method is based on the requirements of ECE Regulation No. 13 of the United Nations, Uniformprovisions concerning the approval of vehicleswith regard to braking. It is therefore recommended that reference should be made to this Regulation to assist with the use of this International Standard. These test methods apply to the type approval of categories O1 and O22) trailers with inertia brakes by testing the control devices on a linear test bench. NOTES 1 In order to understand fully the requirements of this International Standard and to ensure that the test procedures are correctly applied, it is recommended that the regulation is studied before application of this International Standard. 2 Only SI units are used in this International Standard. These test methods apply to the type approval of categories O1 and O21) trailers with inertia brakes by testing on an inertia dynamometer. They relate to mechanically and hydraulically operated braking systems.