Impact attenuating playground surfacing - Methods of test for determination of impact attenuation

This European Standard specifies the test apparatus and the impact test methods for determining the impact attenuation of surfacing by measuring the acceleration experienced during impact. Test apparatus in compliance with this standard are applicable to tests carried out in a laboratory or on site by either methods described.
NOTE   The test methods described in this standard are also applicable for impact areas required in other standards than for playground equipment, e.g. for outdoor fitness equipment and parkour equipment.

Stoßdämpfende Spielplatzböden - Prüfverfahren zur Bestimmung der Stoßdämpfung

Sols d'aires de jeux absorbant l'impact - Méthodes d'essai pour la détermination de l'atténuation de l'impact

Podloge otroških igrišč, ki ublažijo udarce - Ugotavljanje kritične višine padca

Ta evropski standard določa preskusne naprave in metode udarnega preskusa za določanje ublažitve udarca ob podlogo otroških igrišč z merjenjem pospeševanja, ki nastane med udarcem. Preskusne naprave, skladne s tem standardom, se uporabljajo za preskuse, izvedene v laboratoriju ali na kraju uporabe, s katero koli opisano metodo.
OPOMBA: Preskusne metode, opisane v tem standardu, se uporabljajo tudi za območja udarcev, zahtevana v drugih standardih, ki niso namenjeni za opremo otroških igrišč, npr. za zunanjo fitnes opremo in opremo za parkour.

General Information

Status
Published
Publication Date
14-Mar-2019
Technical Committee
Current Stage
6100 - Translation of adopted SIST standards (Adopted Project)
Start Date
14-Feb-2022
Due Date
13-Feb-2023
Completion Date
08-Dec-2022

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2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Stoßdämpfende Spielplatzböden - Prüfverfahren zur Bestimmung der StoßdämpfungSols d'aires de jeux absorbant l'impact - Méthodes d'essai pour la détermination de l'atténuation de l'impactImpact attenuating playground surfacing - Methods of test for determination of impact attenuation97.200.40,JULãþDPlaygroundsICS:Ta slovenski standard je istoveten z:EN 1177:2018+AC:2019SIST EN 1177:2018+AC:2019en,fr,de01-april-2019SIST EN 1177:2018+AC:2019SLOVENSKI

STANDARD
SIST EN 1177:2018+AC:2019
EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
EN 1177:2018+AC
January 2019 ICS 97.200.40 Supersedes EN 1177:2018
English Version

Impact attenuating playground surfacing - Methods of test for determination of impact attenuation

Sols d'aires de jeux absorbant l'impact - Méthodes d'essai pour la détermination de l'atténuation de l'impact

Stoßdämpfende Spielplatzböden - Prüfverfahren zur Bestimmung der Stoßdämpfung This European Standard was approved by CEN on 29 October 2017 and includes the Corrigendum issued by CEN on 9 January 2019.

CEN members are bound to comply 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-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre 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 CEN-CENELEC Management Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom.

EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre:
Rue de la Science 23,

B-1040 Brussels © 2019 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 1177:2018+AC:2019 E SIST EN 1177:2018+AC:2019

EN 1177:2018+AC:2019 (E) 2 Contents
Page

European foreword ....................................................................................................................................................... 4 Introduction .................................................................................................................................................................... 6 1 Scope .................................................................................................................................................................... 8 2 Normative references .................................................................................................................................... 8 3 Terms and definitions ................................................................................................................................... 8 4 Test apparatus.................................................................................................................................................. 9 4.1 Suitability ........................................................................................................................................................... 9 4.2 Components of the apparatus .................................................................................................................. 10 4.3 Accuracy of apparatus ................................................................................................................................ 12 4.3.1 Calibration by a laboratory ...................................................................................................................... 12 4.3.2 Checks by operators .................................................................................................................................... 12 5 Testing procedure ........................................................................................................................................ 13 5.1 Principle of impact measurement .......................................................................................................... 13 5.2 Selection and definition of test positions ............................................................................................ 14 6 Test Method

...................................................... 15 6.1 Principle .......................................................................................................................................................... 15 6.2 Testing in the laboratory ........................................................................................................................... 15 6.3 Testing on site ............................................................................................................................................... 17 7 Test Method 2 – Determination of Impact Attenuation on site ................................................... 18 7.1 Principle .......................................................................................................................................................... 18 7.2 Selection and recording of test positions ............................................................................................ 18 7.3 Carrying out the test .................................................................................................................................... 19 7.4 Results .............................................................................................................................................................. 19 8 Reports ............................................................................................................................................................. 19 8.1 General ............................................................................................................................................................. 19 8.2 Tests carried out in the laboratory with Method 1 .......................................................................... 19 8.3 Tests carried out on site in accordance with Method 1 .................................................................. 20 8.4 Tests carried out on site in accordance with Method 2 .................................................................. 21 Annex A (informative)

Test rig for determination of impact attenuation ............................................ 22 Annex B (informative)

Typical examples of trace of acceleration against time and curve of HIC and gmax values against drop height ........................................................................................... 23 Annex (see 4.3.1.4) .................................................................................................................................................... 25 Annex D (normative)

Procedure for selection of test positions in playgrounds for Method 2 (see Clause 7) ................................................................................................................................................. 26 D.1 Principle .......................................................................................................................................................... 26 D.2 Criteria for selection of test zones (3.12) ............................................................................................ 26 SIST EN 1177:2018+AC:2019

EN 1177:2018+AC:2019 (E) 3 Annex E (normative)

Method for compaction of loose particulate impact attenuating material (see 6.2.4.5.1) ............................................................................................................................... 31 E.1 General ............................................................................................................................................................. 31 E.2 Measurement of layer thickness ............................................................................................................. 31 E.3 Compaction procedure ............................................................................................................................... 31 Annex apparatus ......................................................................................................................................................... 33

SIST EN 1177:2018+AC:2019

EN 1177:2018+AC:2019 (E) 4 European foreword This document (EN 1177:2018+AC:2019) has been prepared by Technical Committee CEN/TC 136 “Sports, playground and other recreational facilities and equipment”, the secretariat of which is held by DIN. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by July 2018, and conflicting national standards shall be withdrawn at the latest by July 2018. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN shall not be held responsible for identifying any or all such patent rights. This document includes Corrigendum 1 issued by CEN on 9 January 2019. This document supersedes ˜EN 1177:2018™. This document includes the corrigendum 1 which corrects item k) in 8.3. The start and finish of text introduced or altered by corrigendum is indicated in the text by tags ˜™. European standards for playground equipment and surfacing comprise this European Standard and the EN 1176 series, which consists of a number of parts as follows: — Part 1: General safety requirements and test methods — Part 2: Additional specific safety requirements and test methods for swings — Part 3: Additional specific safety requirements and test methods for slides — Part 4: Additional specific safety requirements and test methods for cableways — Part 5: Additional specific safety requirements and test methods for carousels — Part 6: Additional specific safety requirements and test methods for rocking equipment — Part 7: Guidance on installation, inspection, maintenance and operation — Part 10: Additional specific safety requirements and test methods for fully enclosed play equipment — Part 11: Additional specific safety requirements and test methods for spatial network This standard should also be read in conjunction with: — EN 1176:2017 series — CEN/TR 16467:2013, Playground equipment accessible for all children — CEN/TR 16598:2014, Collection of rationales for EN 1176 - Requirements — CEN/TR 16396:2012, Playground equipment for children, replies to requests for interpretation of EN 1176:2008 and its parts SIST EN 1177:2018+AC:2019

EN 1177:2018+AC:2019 (E) 5 For inflatable play equipment, see EN 14960, Inflatable play equipment — Safety requirements and test methods. The principal changes from the previous edition of this European Standard are as follows: a) European foreword: References to CEN/TRs added. b) Introduction: Rationale for retaining HIC 1 000 and introducing gmax 200 as upper limits for surfacing when assessed in accordance with this standard has been added. c) Scope: Two methods of impact testing are now provided. Method 1 (as in the previous edition) – Test for determination of Critical Fall Height AND new Method 2 – Test for measurement of impact attenuation on site to enable, upon installation or at periods later in its life, confirmation as required of suitability of the product for that specific site location at the time of the test. d) Body of standard: 1) change of the order and adding new clauses by implementation of Method 2; 2) adaption of recent technology for requirements on test apparatus and measurements in order to improve accuracy of results (including checks by operators); 3) adapting Annex B and adding new Annexes C, D, E and F. According to the CEN-CENELEC Internal Regulations, the national standards organisations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. SIST EN 1177:2018+AC:2019

EN 1177:2018+AC:2019 (E) 6 Introduction This European Standard is based on the safety principles given in EN 1176-1 for playground equipment and provides a method for the assessment of impact attenuation of surfaces intended for use in the impact area as defined in EN 1176-1. This standard (EN 1177) aims to reduce consequences of experiencing risks that are desirable for child development according to the principles set in EN 1176-1. Injuries arise during the use of playground equipment for a variety of reasons and the great majority are minor. Even the presence of protection features like impact attenuating surfacing is known to affect the behaviour of children, as well as carers and play providers, which in turn can affect the risk. The majority of more serious injuries are attributable to falls and there are many factors that influence injury mechanisms during a fall that are independent of the surfacing, e.g. body orientation, awkwardness of fall, bone density, etc. The most severe injuries are likely to be injuries to the head. Recent research has indicated that arm and leg injuries are more frequent and could be influenced by the duration of the acceleration pulse. The committee responsible for this European Standard maintains a constant review of research in this area for possible use in a future revision of this standard. The committee recognizes that there is a relationship between the risk of arm and leg injuries and surface type but takes the view that such injuries are not usually in the most severe category. At present the available injury data can be taken into account by limitation of the maximum (peak) acceleration. Consequently, the committee has chosen to make its priority the reduction of the likelihood of serious head injuries caused by a fall from playground equipment, because even though such injuries are relatively uncommon, they can have the most severe consequences. The severity of injury resulting from an impact to the head can be quantified in terms of Head Injury Criterion (HIC) and the level of HIC = 1 000 together with the upper limit of the peak acceleration of gmax = 200g ( g for gravity) have been chosen as the upper limits for surfacing when assessed in accordance with this standard. Limiting the HIC value at a maximum of 1 000 is equivalent to a 3 % chance of a critical head injury (MAIS1 5), an 18 % probability of a severe (MAIS 4) head injury, a 55 % probability of a serious (MAIS 3) head injury, a 89 % probability of a moderate head injury (MAIS 2), and a 99,5 % chance of a minor head injury (MAIS 1), to an average male adult. Limiting gmax to a maximum of 200g as well as limiting HIC to a maximum of 1 000 takes account of impacts of very short duration and follows the current research on arm injuries as a means of improvement to the Standard. Two methods of impact tests are provided. The first method is for determination of the Critical Fall Height to enable full and detailed confirmation of a product's range of suitability. The second method describes an on-site drop test, without determination of critical fall height to enable, upon installation or at periods later in its life, confirmation as required of the performance of the surfacing in that specific site location at the time of the test. The EN committee is aware of discussions within ASTM International since 2014 about a reduction in the HIC threshold to 700 in its corresponding standard. The current limiting value of HIC

¶ 1 000 has been used in Europe since 1998 and the EN committee considers that at present, there is insufficient evidence of net overall value to playground users to support a change. It has therefore chosen to retain the value HIC

¶ 1 000 and to provide a second threshold of 200g as the criteria of acceptability in this standard, whilst continuing to monitor research publications on this subject. The same has been decided by ASTM for the time being.

1 Maximum Abbreviated Injury Scale, first developed by the Association for the Advancement of Automotive Medicine and used extensively in the automotive industry as an indicator of the severity of head-related injuries. SIST EN 1177:2018+AC:2019

EN 1177:2018+AC:2019 (E) 7 A variety of materials, both natural and synthetic, may be used as impact attenuating surfacing with different attributes and performance. These include grass growing in soil, sand, wood chips, bark, gravel, and various rubber-based products which may be in the form of tiles or continuous coatings or combinations of these materials. Whilst the methods described in this Standard can be used to assess the impact attenuation performance of any of these surfaces, attention of users is drawn that the behaviour of some materials can be highly variable and dependent on prevailing test conditions and that test results will likely vary over time or with climatic conditions. SIST EN 1177:2018+AC:2019

EN 1177:2018+AC:2019 (E) 8 1 Scope This European Standard specifies the test apparatus and the impact test methods for determining the impact attenuation of surfacing by measuring the acceleration experienced during impact. Test apparatus in compliance with this standard are applicable to tests carried out in a laboratory or on site by either methods described. NOTE The test methods described in this standard are also applicable for impact areas required in other standards than for playground equipment, e.g. for outdoor fitness equipment and parkour equipment. 2 Normative references The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 933-1, Tests for geometrical properties of aggregates — Part 1: Determination of particle size distribution — Sieving method EN 1176-1:2017, Playground equipment and surfacing — Part 1: General safety requirements and test methods EN ISO/IEC 17025, General requirements for the competence of testing and calibration laboratories (ISO/IEC 17025) 3 Terms and definitions For the purposes of this document, the terms and definitions given in EN 1176-1 and the following apply. 3.1 impact attenuation property of a surface, which dissipates the kinetic energy of an impact by localized deformation or displacement in such a way that the acceleration experienced by the impacting object is reduced 3.2 impact attenuating surfacing IAS surfacing intended to reduce the risk of injury when falling onto it Note 1 to entry: product or material having the inherent ability to attenuate the impact of a user falling onto it 3.3 critical fall height CFH maximum Free Height of Fall (FHF), for which a surface will provide an adequate level of impact attenuation, determined by test Method 1 as described in Clause 6 of this standard 3.4 head injury criterion HIC measure of the severity of a head injury likely to arise from an impact, determined as described in Clause 5 of this standard SIST EN 1177:2018+AC:2019

EN 1177:2018+AC:2019 (E) 9 3.5 peak acceleration gmax maximum acceleration a experienced by the headform during an impact, expressed in units of g (gravity) 3.6 impact measurement HIC value and gmax calculated from the recorded acceleration a (in g) of the headform falling from one drop height onto one test position of the surface (see 5.1) 3.7 test position position on the surface to be tested, located vertically below the centre of the headform 3.8 drop height Free Height of Fall, measured between the test position on the surface and the lowest point of the free falling headform prior to release; or, in the case of a guided headform, calculated from measurement of headform velocity immediately prior to impact 3.9 drop test procedure for conducting impact measurements on one test position of the impact area Note 1 to entry: The number of drops and the drop heights of drop tests are specified separately in Method 1 for specific types of products (see 6.2.4) and in Method 2 for all types of surfacing material (see 6.3.5). 3.10 loose particulate material material consisting of separate, un-bound pieces of a substance Note 1 to entry: Sand, gravel, bark and wood chips are examples of loose particulate materials. 3.11 impact area area that can be hit by a user after falling through the falling space 3.12 test zone subdivision of the impact area for the purpose of verification of impact attenuation. All test zones to be verified constitute the impact area of the equipment (see 5.2). 4 Test apparatus 4.1 Suitability The same apparatus and recording procedures are used for the two methods of test described in this standard. SIST EN 1177:2018+AC:2019

EN 1177:2018+AC:2019 (E) 10 4.2 Components of the apparatus 4.2.1 General The equipment comprises: a headform (4.2.2) fitted with one or more accelerometer(s) (4.2.2.3 a or b), optionally a signal conditioner (4.2.3), a release system for the headform (4.2.6), means for measuring the effective free fall height (4.2.5), a signal transmission system (4.2.7) and an impact measuring equipment (4.2.8). If using a uniaxial accelerometer, a guidance system for the headform shall be provided (4.2.4). Principle of apparatus see Figure A.1. 4.2.2 Headform 4.2.2.1 The headform shall consist of either a) an aluminium alloy ball; or b) a hemispherical ended aluminium alloy missile. 4.2.2.2 The headform shall have a diameter of 160 mm ± 5 mm, a mass of 4,6 kg ± 0,05 kg, with a maximum deviation from the hemispheric surface of 0,5 mm. If the alloy from which the headform is made is too soft, deformation of the surface of the aluminium may occur when testing loose particulate materials like gravel or any other hard and rigid elements in the impact attenuating surface. This will result in unquantifiable errors in the measurement of gmax and HIC. When testing materials of this type, the impacting surface of the headform should be inspected frequently. If deformation of the headform surface is observed, the test is invalid. In the case of a wired headform, the weight of any connector which is directly attached to or mounted on the headform and the weight of 1,5 m of the wire or cable shall be included in the determination of the mass of the headform. 4.2.2.3 Accelerometer(s) shall be incorporated as follows: a) accelerometer(s) aligned to measure 3 axes for free falling headform, mounted at the centre of gravity (±5mm in the vertical or horizontal axis) of the headform; or b) a uniaxial accelerometer for guided headforms, aligned to measure in the vertical axis ±5° and located directly above the centre of mass. 4.2.2.4 The impacting part of the headform below the mounting plane of the accelerometer shall be homogeneous and free from voids. NOTE This is to avoid errors in measurement caused by vibrations. 4.2.3 Signal conditioner (optional) Depending on the accelerometer technology employed, different methods of signal conditioning may be needed. Examples include: a charge amplifier, a Wheatstone bridge and amplifier, or an integrated electronic conditioner. 4.2.4 Guidance system When using a uniaxial accelerometer, a vertical guidance for the headform shall be provided, including a means to measure the velocity of the headform immediately prior to impact (see 4.2.5.2). SIST EN 1177:2018+AC:2019

EN 1177:2018+AC:2019 (E) 11 4.2.5 Fall height measuring equipment Methods for determination of the effective Free Height of Fall (FHF) of the headform when impacting the surface are: 4.2.5.1 For the free-fall impact test, physical measuring of the drop height or calculating the drop height from the measured time between release and contact of the headform with the surface. When calculating the drop height from the measured time between release and contact of the headform with the surface, special attention should be paid to possible time differences between the start of time measurement and the effective release of the headform (e.g. caused by permanent magnetism in a magnetic release system). A comparison of the measured height of fall and the calculated height of fall may be needed. 4.2.5.2 For the guided impact test, measuring the velocity of the headform immediately prior to the impact and calculating the theoretical free fall drop height. To allow for frictional losses, the velocity of the headform immediately prior to impact is recorded in order to calculate the equivalent drop height as if the headform had been in free fall. In all cases, the effective Free Height of Fall (FHF) shall be recorded. 4.2.6 Release system The release system for the free-fall impact test shall not create a significant rotation moment or any other forces on the headform, when released. NOTE A rotation moment or other forces on the headform would cause additional accelerations at impact in the accelerometer, leading to an uncontrollable error of the resultant for the vertical measurement. 4.2.7 Signal transmission system When using a signal cable for transmission, it shall not cause any significant restraining, pushing forces or unsteadiness of the headform. 4.2.8 Impact measuring equipment 4.2.8.1 The impact measuring equipment shall consist of an accelerometer measurement system (4.2.8.2), a recording device (4.2.8.3) and a calculation program for the head injury criterion (HIC) (4.2.8.4). 4.2.8.2 The accelerometer measurement system shall be capable of measuring all signal frequencies in the range 20 Hz to 1 000 Hz and having a sufficient response at all frequencies to keep amplitude errors below 5 %. It shall be capable of measuring, recording and displaying the acceleration and time duration of each complete impact (see 5.1.3). For piezoelectric accelerometers, to have a sufficient response at low frequenciesá the

« u dB lower limiting frequency should be less than or equal to 0,3 Hz to reduce the errors resulting from signal droop, which is most obviously visible in the form of baseline overshoot after the impact. Signal droop also results in underestimation of gmax and as a result HIC, particularly for longer pulse durations. Piezoelectric accelerometers with a time constant of 2 s or greater and appropriate signal conditioning will generally meet this requirement. Other accelerometers are not affected. SIST EN 1177:2018+AC:2019

EN 1177:2018+AC:2019 (E) 12 4.2.8.3 Recording device The recording device shall be capable of capturing and recording the acceleration/time signals produced throughout an impact with a minimum sampling rate of at least 20 kHz, including the maximum acceleration (gmax) experienced during each impact. Signal conditioning and filtering shall be compatible with the accelerometer and the data channel specified. When the

« u dB upper frequency response of the accelerometer and its signal conditioning system is at a frequency greater than one-quarter of the sampling frequency, an anti-aliasing filter with an attenuation of at least 30 dB at half the sampling rate shall be employed. 4.2.8.4 Program for calculating the HIC value for the recorded acceleration time history of each impact, in accordance with Clause 5. 4.3 Accuracy of apparatus 4.3.1 Calibration by a laboratory 4.3.1.1 The apparatus shall be calibrated periodically, by a laboratory in accordance with EN ISO/IEC 17025. 4.3.1.2 All parts of the acceleration measurement system including accelerometers and electronic part (analogue and numerical) shall be calibrated for the whole frequency range from 20 Hz to 1 000 Hz. Recalibration shall be carried out at time intervals recommended by the manufacturer of the accelerometer or at least every two years. Calibrations shall be documented (e.g. by calibration certificates) and uncertainties shall be indicated. The uncertainty of the calibration of accelerometers shall not be greater than 5 %. 4.3.1.3 Velocity measurement systems as well as algorithms for calculating the fall height shall be calibrated for the whole velocity range (up to 3.5 m drop height). For free falling headforms the calculated fall height shall be compared with the physically measured effective fall height. In all cases, the effective Free Height of Fall (FHF) shall be measured with an uncertainty of not more than ±1 %. 4.3.1.4 The computer algorithm used for the calculation of HIC shall be checked, e.g. by imposing a half-sine curve and the result, when compared with an independent mathematical calculation of this curve, shall not deviate by more than ±1 %. NOTE An example for verification is given in Annex C. 4.3.2 Checks by operators 4.3.2.1 Operators shall verify the correct function of the apparatus they use at appropriate interval (depending on the frequency and type of use of the apparatus). The results of any checks shall be recorded during the life time of the apparatus (e.g. by using a monitoring log). The tests given in 4.3.2.2 and 4.3.2.3 are for checking any deviations or anomalies in the components and neither replaces calibration nor the validation for compliance o

...

SIST EN 1177:2018+AC
S L O V E N S K I
S T A N D A R D april 2019
Podloge otroških igrišč, ki ublažijo udarce – Ugotavljanje kritične višine
padca
Impact attenuating playground surfacing – Methods of test for determination of
impact attenuation
Stoßdämpfende Spielplatzböden – Prüfverfahren zur Bestimmung der
Stoßdämpfung

Sols d'aires de jeux absorbant l'impact – Méthodes d'essai pour la détermination

de l'atténuation de l'impact
Referenčna oznaka
SIST EN 1177:2018+AC:2019 (sl)
ICS 97.200.40
Nadaljevanje na straneh II do III in od 1 do 32

2023-01. Slovenski inštitut za standardizacijo. Razmnoževanje ali kopiranje celote ali delov tega dokumenta ni dovoljeno.

---------------------- Page: 1 ----------------------
SIST EN 1177:2018+AC : 2019
NACIONALNI UVOD

SIST EN 1177:2018+AC (sl), Podloge otroških igrišč, ki ublažijo udarce – Ugotavljanje kritične višine

padca, 2019, ima status slovenskega standarda in je istoveten evropskemu standardu EN

1177:2018+AC (en, de, fr), Impact attenuating playground surfacing – Methods of test for determination

of impact attenuation, 2019.
Ta standard nadomešča SIST EN 1177:2018.
NACIONALNI PREDGOVOR

Evropski standard EN 1177:2018+AC:2019 je pripravil tehnični odbor Evropskega komiteja za

standardizacijo CEN/TC 136 Športna oprema, oprema za igrišča in druga oprema za rekreacijo.

Slovenski standard SIST EN 1177:2018+AC:2019 je prevod evropskega standarda EN

1177:2018+AC:2019. V primeru spora glede besedila slovenskega prevoda v tem standardu je odločilen

izvirni evropski standard v enem od treh uradnih jezikov CEN. Slovensko izdajo standarda je pripravil

tehnični odbor SIST/TC SPO Šport.
Odločitev za privzem tega standarda je 7. marca 2019 sprejel SIST/TC SPO Šport.
ZVEZA S STANDARDI

S privzemom tega evropskega standarda veljajo za omejeni namen referenčnih standardov vsi

standardi, navedeni v izvirniku, razen standarda, ki je že sprejet v nacionalno standardizacijo:

SIST EN 933-1 Preskusi geometričnih lastnosti agregatov – 1. del: Ugotavljanje zrnavosti

– Metoda sejanja

SIST EN 1176-1:2018 Oprema in podloge otroških igrišč – 1. del: Splošne varnostne zahteve in

preskusne metode

SIST EN ISO/IEC 17025 Splošne zahteve za usposobljenost preskuševalnih in kalibracijskih

laboratorijev (ISO/IEC 17025)
OSNOVA ZA IZDAJO STANDARDA
– privzem standarda EN 1177:2018+AC:2019
PREDHODNA IZDAJA

– standard SIST EN 1177:2018, Podloge otroških igrišč, ki ublažijo udarce – Ugotavljanje kritične

višine padca
OPOMBE

 Povsod, kjer se v besedilu standarda uporablja izraz "evropski standard", v SIST EN

1177:2018+AC:2019 to pomeni "slovenski standard".
 Uvod in nacionalni predgovor nista sestavni del standarda.
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SIST EN 1177:2018+AC : 2019

 Ta nacionalni dokument je istoveten EN 1177:2018+AC:2019 in je objavljen z dovoljenjem

CEN-CENELEC
Upravni center
Rue de la Science 23
B-1040 Bruselj

This national document is identical with EN 1177:2018+AC:2019 and is published with the

permission of
CEN-CENELEC
Management Centre
Rue de la Science 23
B-1040 Brussels
III
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SIST EN 1177:2018+AC : 2019
(prazna stran)
---------------------- Page: 4 ----------------------
EVROPSKI STANDARD EN 1177:2018+AC
EUROPEAN STANDARD
januar 2019
NORME EUROPÉENNE
EUROPÄISCHE NORM
ICS 97.200.40 Nadomešča EN 1177:2018
Slovenska izdaja
Podloge otroških igrišč, ki ublažijo udarce –
Ugotavljanje kritične višine padca

Impact attenuating playground Sols d'aires de jeux absorbant Stoßdämpfende Spielplatz-

surfacing – Methods of test for l'impact – Méthodes d'essai böden – Prüfverfahren zur

determination of impact pour la détermination de Bestimmung der Stoßdämpfung
attenuation l'atténuation de l'impact

Ta evropski standard je CEN sprejel 29. oktobra 2017 in vključuje popravek, ki ga je CEN izdal

9. januarja 2019.

Člani CEN morajo izpolnjevati določila notranjih predpisov CEN/CENELEC, s katerimi je predpisano, da

mora biti ta evropski standard brez kakršnihkoli sprememb sprejet kot nacionalni standard. Seznami

najnovejših izdaj teh nacionalnih standardov in njihovi bibliografski podatki so na voljo na zahtevo pri

Upravnem centru CEN-CENELEC ali kateremkoli članu CEN.

Ta evropski standard obstaja v treh uradnih izdajah (angleški, francoski in nemški). Izdaje v drugih

jezikih, ki jih člani CEN na lastno odgovornost prevedejo in izdajo ter prijavijo pri Upravnem centru CEN-

CENELEC, veljajo kot uradne izdaje.

Člani CEN so nacionalni organi za standarde Avstrije, Belgije, Bolgarije, Cipra, Češke republike,

Danske, Estonije, Finske, Francije, Grčije, Hrvaške, Irske, Islandije, Italije, Latvije, Litve, Luksemburga,

Madžarske, Malte, Nekdanje jugoslovanske republike Makedonije, Nemčije, Nizozemske, Norveške,

Poljske, Portugalske, Romunije, Slovaške, Slovenije, Srbije, Španije, Švedske, Švice, Turčije in

Združenega kraljestva.
CEN
Evropski komite za standardizacijo
European committee for standardization
Comité européen de normalisation
Europäisches komitee für normung
Upravni center CEN-CENELEC: Rue de la Science 23, B-1040 Bruselj

© 2019 CEN Vse pravice do izkoriščanja v kakršnikoli obliki in na Ref. oznaka EN 1177:2018+AC:2019 E

kakršenkoli način imajo nacionalni člani CEN.
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SIST EN 1177:2018+AC : 2019
VSEBINA Stran

Evropski predgovor .................................................................................................................................. 4

Uvod ........................................................................................................................................................ 6

1 Področje uporabe ................................................................................................................................. 8

2 Zveze s standardi ................................................................................................................................. 8

3 Izrazi in definicije .................................................................................................................................. 8

4 Preskusna naprava ............................................................................................................................... 9

4.1 Primernost ......................................................................................................................................... 9

4.2 Sestavni deli naprave ........................................................................................................................ 9

4.3 Točnost naprave ..............................................................................................................................11

4.3.1 Umerjanje v laboratoriju ...............................................................................................................11

4.3.2 Preverjanje, ki ga izvajajo izvajalci ...............................................................................................12

5 Preskusni postopek ............................................................................................................................13

5.1 Načelo merjenja udarca...................................................................................................................13

5.2 Izbira in opredelitev preskusnih mest ..............................................................................................14

6 Preskusna metoda 1: ugotavljanje kritične višine padca (CFH) .........................................................14

6.1 Načelo .............................................................................................................................................14

6.2 Preskus v laboratoriju ......................................................................................................................14

6.3 Preskus na mestu uporabe .............................................................................................................16

7 Preskusna metoda 2: določanje ublažitve udarca na mestu uporabe ...............................................17

7.1 Načelo .............................................................................................................................................17

7.2 Izbira in beleženje preskusnih mest ................................................................................................17

7.3 Izvajanje preskusa ...........................................................................................................................18

7.4 Rezultati ...........................................................................................................................................18

8 Poročila ................................................................................................................................................18

8.1 Splošno ............................................................................................................................................18

8.2 Preskusi, izvedeni v laboratoriju z metodo 1 ...................................................................................18

8.3 Preskusi, izvedeni na mestu uporabe v skladu z metodo 1 ............................................................19

8.4 Preskusi, izvedeni na mestu uporabe v skladu z metodo 2 ............................................................19

Dodatek A (informativni): Preskusna oprema za določanje ublažitve udarca ........................................21

Dodatek B (informativni): Tipična primera sledi pospeška v odvisnosti od časa ter krivulje

za vrednosti HIC in g v odvisnosti od višine padca ..........................................................................22

max

Dodatek C (informativni): Preverjanje računalniškega algoritma, ki se uporablja za izračun

vrednosti HIC (glej točko 4.3.1.4).........................................................................................................24

Dodatek D (normativni): Postopek za izbiro preskusnih mest na igriščih za metodo 2

(glej točko 7).........................................................................................................................................25

D.1 Načelo .............................................................................................................................................25

D.2 Merila za izbiro preskusnih območij (3.12) .....................................................................................25

Dodatek E (normativni): Metoda za stiskanje sipkega materiala, ki ublaži udarce

(glej točko 6.2.4.5.1) ............................................................................................................................30

E.1 Splošno ...........................................................................................................................................30

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SIST EN 1177:2018+AC : 2019

E.2 Merjenje debeline sloja ...................................................................................................................30

E.3 Postopek stiskanja ..........................................................................................................................30

Dodatek F (informativni): Primer režima za preverjanje delovanja preskusne naprave HIC ................32

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SIST EN 1177:2018+AC : 2019
Evropski predgovor

Ta dokument (EN 1177:2018+AC:2019) je pripravil tehnični odbor CEN/TC 136 "Športna oprema,

oprema za igrišča in druga oprema za rekreacijo", katerega sekretariat vodi DIN.

Ta evropski standard mora dobiti status nacionalnega standarda bodisi z objavo istovetnega besedila

bodisi z razglasitvijo najpozneje do julija 2018, nasprotujoče nacionalne standarde pa je treba razveljaviti

najpozneje julija 2018.

Opozoriti je treba na možnost, da so nekateri elementi tega dokumenta lahko predmet patentnih pravic.

CEN ni odgovoren za ugotavljanje posameznih ali vseh takih patentnih pravic.
Ta dokument vključuje Popravek 1, ki ga je CEN izdal 9. januarja 2019.
Ta dokument nadomešča standard EN 1177:2018 .
Ta dokument vključuje Popravek 1, ki popravlja alinejo k) v točki 8.3.

Začetek in konec besedila, dodanega ali spremenjenega s popravkom, sta označena z oznakama

Evropski standardi za opremo in podloge otroških igrišč zajemajo ta evropski standard in skupino

standardov EN 1176, ki je sestavljena iz več delov:
– 1. del: Splošne varnostne zahteve in preskusne metode

– 2. del: Dodatne posebne varnostne zahteve in preskusne metode za viseče gugalnice

– 3. del: Dodatne posebne varnostne zahteve in preskusne metode za tobogane
– 4. del: Dodatne posebne varnostne zahteve in preskusne metode za vrvne proge
– 5. del: Dodatne posebne varnostne zahteve in preskusne metode za vrtiljake

– 6. del: Dodatne posebne varnostne zahteve in preskusne metode za oporne gugalnice

– 7. del: Navodila za vgradnjo, nadzor, vzdrževanje in delovanje

– 10. del: Dodatne posebne varnostne zahteve in preskusne metode za zaključene igralne enote

– 11. del: Dodatne posebne varnostne zahteve in preskusne metode za prostorske mreže

Ta standard naj bi se uporabljal tudi v povezavi z naslednjim:
– skupina standardov EN 1176:2017
– CEN/TR 16467:2013, Oprema otroških igrišč, dostopna vsem otrokom
– CEN/TR 16598:2014, Zbirka osnovnih utemeljitev za EN 1176 – Zahteve

– CEN/TR 16396:2012, Oprema otroških igrišč – Odgovori na zahtevke za interpretacijo EN

1176:2008 in njegovih delov

Za napihljivo igralno opremo glej EN 14960, Napihljiva igralna oprema – Varnostne zahteve in

preskusne metode.

V primerjavi s prejšnjo izdajo tega evropskega standarda so glavne spremembe naslednje:

a) evropski predgovor: dodana so sklicevanja na standarde CEN/TR,

b) uvod: dodana je osnovna utemeljitev za ohranitev vrednosti HIC = 1 000 in uvedbo vrednosti

g = 200 kot zgornjih mej za podloge pri ocenjevanju v skladu s tem standardom,
max
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SIST EN 1177:2018+AC : 2019

c) področje uporabe: zdaj sta podani dve metodi za preskus z udarcem – metoda 1 (kot v prejšnji

izdaji standarda), ki vključuje preskus za ugotavljanje kritične višine padca, IN nova metoda 2, ki

vključuje preskus za merjenje ublažitve udarca na mestu uporabe, s čimer se ob namestitvi oziroma

pozneje med uporabo izdelka omogoči potrditev njegove primernosti za to določeno mesto v času

preskusa (če je to potrebno),
d) besedilo standarda:
1) vrstni red je spremenjen in dodane so nove točke z izvajanjem metode 2,

2) najnovejša tehnologija je prilagojena zahtevam za preskusne naprave in meritev za izboljšanje

točnosti rezultatov (vključno s preverjanjem, ki ga izvajajo izvajalci),
3) dodatek B je prilagojen ter dodani so novi dodatki C, D, E in F.

V skladu z notranjimi predpisi CEN-CENELEC morajo ta evropski standard obvezno uvesti nacionalne

organizacije za standardeo naslednjih držav: Avstrije, Belgije, Bolgarije, Cipra, Češke republike,

Danske, Estonije, Finske, Francije, Grčije, Hrvaške, Irske, Islandije, Italije, Latvije, Litve, Luksemburga,

Madžarske, Malte, Nekdanje jugoslovanske republike Makedonije, Nemčije, Nizozemske, Norveške,

Poljske, Portugalske, Romunije, Srbije, Slovaške, Slovenije, Španije, Švedske, Švice, Turčije in

Združenega kraljestva.
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SIST EN 1177:2018+AC : 2019
Uvod

Ta evropski standard temelji na varnostnih načelih iz standarda EN 1176-1 za opremo otroških igrišč in

podaja metodo za ocenjevanje zmožnosti ublažitve udarca za podloge, namenjene za uporabo v

območju udarca, kot je opredeljeno v standardu EN 1176-1. Namen tega standarda (EN 1177) je

zmanjšati posledice izpostavljenosti tveganjem, ki so zaželena za razvoj otrok v skladu z načeli iz

standarda EN 1176-1.

Do poškodb pri uporabi opreme otroških igrišč prihaja iz različnih razlogov in velika večina teh poškodb

je lažja. Kot je znano, na vedenje otrok, njihovih skrbnikov in vzgojiteljev vpliva celo prisotnost zaščitnih

elementov, kot je podloga, ki ublaži udarce, kar lahko posledično vpliva na tveganje. Večina težjih

poškodb je posledica padcev. Dejavnikov, ki vplivajo na mehanizme poškodb pri padcu, je veliko in niso

odvisni od podloge, npr. usmerjenost telesa, neroden padec, gostota kosti itd.

Najtežje poškodbe so najverjetneje poškodbe glave. Nedavne raziskave so pokazale, da so poškodbe

rok in nog pogostejše, nanje pa lahko vpliva trajanje impulza pospeševanja. Odbor, pristojen za ta

evropski standard, redno pregleduje raziskave na tem področju, ki bi se lahko uporabile v prihodnji

reviziji tega standarda. Odbor priznava, da obstaja povezava med tveganjem za poškodbe rok in nog

ter vrsto podloge, vendar meni, da pri tem navadno ne gre za najtežje poškodbe. Razpoložljive podatke

o poškodbah je trenutno mogoče upoštevati z omejitvijo največjega (vršnega) pospeška.

Zato je prednostna naloga odbora zmanjšati verjetnost resnih poškodb glave zaradi padca z opreme

otroških igrišč, saj imajo takšne poškodbe, čeprav so razmeroma redke, lahko najresnejše posledice.

Resnost poškodbe, ki je posledica udarca v glavo, je mogoče določiti s kriterijem poškodbe glave (HIC),

pri čemer raven HIC = 1 000 in zgornja meja vršnega pospeška g = 200 g (g kot težnost) predstavljata

max
zgornji meji za ocenjevanje podlog v skladu s tem standardom.

Omejitev vrednosti HIC na največ 1 000 ustreza 3-odstotni možnosti kritične poškodbe glave (MAIS

5), 18-odstotni možnosti težje poškodbe glave (MAIS 4), 55-odstotni možnosti hude poškodbe glave

(MAIS 3), 89-odstotni možnosti zmerne poškodbe glave (MAIS 2) in 99,5-odstotni možnosti lažje

poškodbe glave (MAIS 1) pri povprečnem odraslem moškem.

Omejitev vrednosti g na največ 200 g in omejitev vrednosti HIC na največ 1 000 upoštevata udarce,

max

ki trajajo zelo kratek čas, za izboljšanje standarda pa sledita raziskavam o poškodbah rok.

Podani sta dve metodi za preskus z udarcem. Prva metoda se uporablja za ugotavljanje kritične višine

padca, s čimer se omogoči popolno in podrobno potrjevanje obsega primernosti posameznega izdelka.

Druga metoda opisuje preskus na mestu uporabe brez ugotavljanja kritične višine padca, s čimer se ob

namestitvi oziroma pozneje med uporabo izdelka omogoči potrditev učinkovitosti podloge na tem

določenem mestu v času preskusa (če je to potrebno).

Odbor za ta EN je seznanjen z razpravami o znižanju mejne vrednosti HIC na 700 v ustreznem

standardu, ki potekajo znotraj organizacije ASTM International že od leta 2014. Trenutna mejna

vrednost HIC ≤ 1 000 se v Evropi uporablja od leta 1998 in odbor za ta EN meni, da trenutno ni dovolj

dokazov o neto skupni vrednosti za uporabnike otroških igrišč, na podlagi katerih bi lahko podprl

spremembe. Odbor se je zato odločil, da bo ohranil vrednost HIC ≤ 1 000 in kot kriterij sprejemljivosti v

tem standardu zagotovil drugo mejno vrednost 200 g, obenem pa bo še naprej spremljal znanstvene

objave na to temo. Organizacija ASTM se je za zdaj odločila enako.

Maximum Abbreviated Injury Scale oz. popolnoma skrajšana lestvica poškodb, ki jo je prvič predstavilo Združenje za napredek

avtomobilske medicine (AAAM) in se v avtomobilski industriji obsežno uporablja kot kazalnik resnosti poškodb glave.

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SIST EN 1177:2018+AC : 2019

Kot podloge, ki ublažijo udarce, se lahko uporabljajo različni materiali (tako naravni kot sintetični) z

različnimi lastnostmi in zmogljivostjo. Sem spadajo trava, ki raste v zemlji, pesek, lesni sekanci, lubje,

gramoz in različni izdelki na osnovi gume, bodisi v obliki ploščic ali enakomernih nanosov oziroma

kombinacije teh materialov. Čeprav je metode, opisane v tem standardu, mogoče uporabiti za

ocenjevanje zmogljivosti ublažitve udarcev katerekoli od teh podlog, je treba uporabnike opozoriti, da je

lahko obnašanje nekaterih materialov zelo spremenljivo in odvisno od prevladujočih preskusnih pogojev

ter da se bodo rezultati preskusov verjetno sčasoma (oziroma glede na podnebne pogoje) razlikovali.

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SIST EN 1177:2018+AC : 2019
1 Področje uporabe

Ta evropski standard določa preskusne naprave in metode preskusa z udarcem za določanje ublažitve

udarca ob podlogo otroških igrišč z merjenjem pospeševanja, ki nastane med udarcem. Preskusne

naprave, skladne s tem standardom, se uporabljajo za preskuse, izvedene v laboratoriju ali na mestu

uporabe, s katerokoli opisano metodo.

OPOMBA: Preskusne metode, opisane v tem standardu, se uporabljajo tudi za območja udarcev, zahtevana v drugih

standardih, ki ne obravnavajo opreme otroških igrišč, npr. za zunanjo opremo za telesno vadbo in opremo za

parkour.
2 Zveze s standardi

Navedeni dokumenti so, v celoti ali delno, povezani s tem dokumentom in so nepogrešljivi pri njegovi

uporabi. Pri datiranih sklicevanjih se uporablja samo navedena izdaja. Pri nedatiranih sklicevanjih se

uporablja zadnja izdaja citiranega dokumenta (vključno z morebitnimi dopolnili).

EN 933-1 Preskusi geometričnih lastnosti agregatov – 1. del: Ugotavljanje zrnavosti –

Metoda sejanja

EN 1176-1:2017 Oprema in podloge otroških igrišč – 1. del: Splošne varnostne zahteve in

preskusne metode

EN ISO/IEC 17025 Splošne zahteve za usposobljenost preskuševalnih in kalibracijskih

laboratorijev (ISO/IEC 17025)
3 Izrazi in definicije

V tem dokumentu se uporabljajo izrazi in definicije, podani v standardu EN 1176-1, in tudi spodaj

navedeni.
3.1
ublažitev udarca

lastnost podloge, ki razprši kinetično energijo udarca z lokalizirano deformacijo ali premikom tako, da

se zmanjša pospešek predmeta, ki udari ob podlogo
3.2
podloga, ki ublaži udarce
IAS
podloga, namenjena zmanjšanju nevarnosti poškodb pri padcu nanjo

Opomba 1: Izdelek ali material s svojstveno zmožnostjo ublažitve udarca uporabnika pri padcu nanj.

3.3
kritična višina padca
CFH

največja višina prostega padca (FHF), za katero podloga zagotavlja zadostno raven ublažitve udarca,

ki se določi s preskusno metodo 1 v skladu s točko 6 tega standarda
3.4
kriterij poškodbe glave
HIC

kriterij resnosti poškodbe glave, do katere bi lahko prišlo zaradi udarca, ki se določi v skladu s točko 5

tega standarda
3.5
vršni pospešek
max

največji pospešek a, ki pri udarcu deluje na model glave, izražen v enotah g (težnost)

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SIST EN 1177:2018+AC : 2019
3.6
meritev udarca

vrednosti HIC in g , ki se izračunata iz zabeleženega pospeška a (v enotah g) modela glave pri padcu

max
z določene višine na določeno preskusno mesto na podlogi (glej točko 5.1)
3.7
preskusno mesto
mesto na preskušani podlogi navpično pod središčem modela glave
3.8
višina padca

višina prostega padca, izmerjena med preskusnim mestom na podlogi in najnižjo točko prosto

padajočega modela glave pred sprožitvijo (pri vodenem modelu glave se izračuna iz meritve hitrosti

modela glave tik pred udarcem)
3.9
preskus s padcem
postopek za izvajanje meritev udarca na preskusnem mestu v območju udarca

Opomba 1: Število padcev in višine pri preskusih s padcem so določeni ločeno v metodi 1 za posamezne vrste izdelkov (glej

točko 6.2.4) ter v metodi 2 za vse vrste materiala za podloge (glej točko 6.3.5).

3.10
sipki material
material, sestavljen iz ločenih, nevezanih delov snovi
Opomba 1: Primeri sipkih materialov so pesek, gramoz in lesni sekanci.
3.11
območje udarca
območje, v katerem lahko oseba po padcu udari ob podlago
3.12
preskusno območje

predel območja udarca, namenjen preverjanju ublažitve udarca; vsa preskusna območja, ki jih je treba

preveriti, sestavljajo območje udarca opreme (glej točko 5.2)
4 Preskusna naprava
4.1 Primernost

Enaka preskusna naprava in postopki beleženja se uporabljajo pri obeh preskusnih metodah, opisanih

v tem standardu.
4.2 Sestavni deli naprave
4.2.1 Splošno

Oprema vključuje: model glave (točka 4.2.2), opremljen z enim ali več merilniki pospeška (točka 4.2.2.3,

a ali b), izbirno napravo za kondicioniranje signala (točka 4.2.3), sistem sprožitve modela glave (točka

4.2.6), pripomoček za merjenje efektivne višine prostega padca (točka 4.2.5), sistem prenosa signala

(točka 4.2.7) in opremo za merjenje udarca (točka 4.2.8).

Pri uporabi enoosnega merilnika pospeška je treba zagotoviti sistem za vodenje modela glave (glej

točko 4.2.4). Koncept naprave je prikazan na sliki A.1.
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SIST EN 1177:2018+AC : 2019
4.2.2 Model glave
4.2.2.1 Model glave mora vključevati:
a) kroglo iz aluminijeve zlitine ali
b) projektil s polkrožnim dnom iz aluminijeve zlitine.

4.2.2.2 Model glave mora imeti premer 160 mm ± 5 mm in maso 4,6 kg ± 0,05 kg, pri čemer je največje

odstopanje od polkrožne površine 0,5 mm.

Če je zlitina, iz katere je izdelan model glave, premehka, lahko pri preskušanju sipkih materialov, kot je

gramoz, oziroma katerihkoli drugih trdnih in togih elementov na podlogi, ki ublaži udarce, pride do

deformacije površine aluminija. To bo povzročilo neizmerljive napake pri merjenju vrednosti g in HIC.

max

Pri preskušanju materialov te vrste je površino, ob katero udari model glave, priporočljivo pogosto

pregledovati. Če se model glave deformira, je preskus neveljaven.

Če je model glave ožičen, je treba v določitev mase modela glave vključiti maso priključka, ki je pritrjen

oziroma nameščen neposredno na model glave, in maso žice ali kabla z dolžino 1,5 m.

4.2.2.3 V opremo je treba vključiti naslednje merilnike pospeška:

a) merilnik pospeška (oz. več merilnikov), ki je poravnan tako, da omogoča meritve treh osi za prosto

padajoči model glave in je nameščen v težišču (± 5 mm na navpični ali vodoravni osi) modela glave;

oziroma

b) enoosni merilnik pospeška za vodene modele glave, ki je poravnan tako, da omogoča meritve na

navpični osi ± 5° in je nameščen neposredno nad masnim središčem.

4.2.2.4 Del modela glave pod pritrditveno ploskvijo merilnika pospeška, ki udari ob podlogo, mora biti

homogen in brez votlin.
OPOMBA: To je potrebno za preprečevanje napak pri merjenju zaradi vibracij.
4.2.3 Naprava za kondicioniranje signala (izbirno)

Glede na uporabljeno tehnologijo merilnika pospeška bodo morda potrebne različne metode

kondicioniranja signala. Primeri takšnih metod so ojačevalnik naboja, Wheatstonov mostiček in

ojačevalnik ali integrirana elektronska naprava za kondicioniranje.
4.2.4 Sistem za vodenje

Pri uporabi enoosnega merilnika pospeška je treba zagotoviti navpično vodenje modela glave, vključno

s pripomočkom za merjenje hitrosti modela glave tik pred udarcem (glej točko 4.2.5.2).

4.2.5 Oprema za merjenje višine padca

Metode za določanje efektivne višine prostega padca (FHF) modela glave pri udarcu ob podlogo so:

4.2.5.1 Pri preskusu s prostim padcem: fizično merjenje višine padca oziroma izračun višine padca iz

izmerjenega časa med sprožitvijo in dotikom modela glave s podlogo.

Pri izračunu višine padca iz izmerjenega časa med sprožitvijo in dotikom modela glave s podlogo naj se

posebna pozornost posveti možnim razlikam v času med začetkom merjenja časa in dejansko sprožitvijo

modela glave (npr. zaradi trajnega magnetizma v magnetnem sprožilnem elementu). Morda bo potrebna

primerjava izmerjene višine padca in izračunane višine padca.

4.2.5.2 Pri preskusu z vodenim udarcem: merjenje hitrosti modela glave tik pred udarcem in izračun

teoretične višine prostega padca.
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SIST EN 1177:2018+AC : 2019

Za upoštevanje izgub zaradi trenja se zabeleži hitrost modela glave tik pred udarcem, da se lahko

izračuna enakovredna višina padca kot pri prostem padcu modela glave.
V vseh primerih je treba zabeležiti efektivno višino prostega padca.
4.2.6 Sistem sprožitve

Sistem sprožitve ob sproženju pri preskusu s prostim padcem ne sme ustvariti opaznega rotacijskega

momenta ali kakršnihkoli drugih sil, ki delujejo na model glave.

OPOMBA: Rotacijski moment oziroma druge sile, ki delujejo na model glave, bi povzročile dodatne pospeške ob udarcu v

merilniku pospeška, zaradi česar bi prišlo do neobvladljive napake rezultata za navpično meritev.

4.2.7 Sistem prenosa signala

Signalni kabel, ki se uporablja za prenos, ne sme povzročiti nobenih opaznih oviralnih in potisnih sil

oziroma nestabilnost modela glave.
4.2.8 Oprema za merjenje udarca

4.2.8.1 Oprema za merjenje udarca mora vključevati sistem merjenja z merilnikom pospeška (točka

4.2.8.2), napravo za beleženje (točka 4.2.8.3) in program za izračun kriterija poškodbe glave (HIC)

(točka 4.2.8.4).

4.2.8.2 Sistem merjenja z merilnikom pospeška mora omogočati merjenje vseh frekvenc signala v

območju 20 Hz do 1 000 Hz in zagotavljati zadostno odzivnost pri vseh frekvencah, da amplitudno

odstopanje ne preseže 5 %. Omogočati mora merjenje, beleženje ter prikaz pospeška in trajanja

posameznega udarca (glej točko 5.1.3).

Za zadosten odziv piezoelektričnih merilnikov pospeška pri nizkih frekvencah naj bo spodnja frekvenčna

meja −3 dB man
...

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