【正文】 e in twice at intervals of (60 177。 0,25) mm above the forcemeasuring assembly. Allow the weight to fall onto the force measuring assembly. Record the peak force applied to the surface in the course of the impact. Repeat the procedure described in ten times, giving a total of eleven impacts. Record the mean value of the peak force from the second to the eleventh impact and denote it as Fr. The value of Fr shall lie in the range (6,60 177。 0,5 dB of the expected response, calculated on the basis of the Butterworth function. EN 14808:2020 (E) 8 Licensed copy: The University of Hong Kong, The University of Hong Kong, Version correct as of 14/03/2020 06 BSI The system should be able to record the peak value of single forcepulse signals of 10 ms duration with an uncertainty of no greater than 177。 0,3) kg. Means of supporting the weight, allowing it to be set to the drop height with an uncertainty no greater than 177。 0,1) mm and a minimum thickness of 10 mm. Metal guiding tube having an internal diameter of (71,0 177。 60) N/mm over the range 0,1 kN to 7,5 kN with a hardened upper plate. The spring should have three or more coaxial coils which shall be rigidly fixed together at their ends. This may be achieved, for instance, by milling the spring from a single piece of steel. Adjustable supporting feet, at least 250 mm from the point of application of the load for a point elastic sports surface and at least 600 mm from the point of application of the load for an area elastic sports surface. Steel base plate, having a lower side rounded to a radius of 500 mm。 0,1) kg with a hardened striking surface guided so that it is allowed to fall smoothly and vertically with minimum friction. Spiral spring, having a diameter of (69 177。 2) 176。 R NOR M UNG Management Centre: rue de Stassart, 36 B1050 Brussels 169。E N DE NOR M A L I S A T I O N EUR O P 196。den Bestimmung des Kraftabbaus This European Standard was approved by CEN on 28 November 2020. CEN members are bound to ply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up todate lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION C O M I T 201。termination de l39。ENNE EUROP196。 — monitor related international and European developments and promulgate them in the UK. A list of anizations represented on this mittee can be obtained on request to its secretary. Crossreferences The British Standards which implement international or European publications referred to in this document may be found in the BSI Catalogue under the section entitled ―International Standards Correspondence Index‖, or by using the ―Search‖ facility of the BSI Electronic Catalogue or of British Standards Online. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This docum ent prises a front cover, an inside front cover, the EN title page, pages 2 to 8, an inside back cover and a back cover. The BSI copyright notice displayed in this document indicates when the document was last issued. This British Standard was published under the authority of the Standards Policy and Strategy Committee on 30 June 2020 169。Licensed copy