标题: EN 71-1:2005/prA8:2008 [打印本页] 作者: tanger 时间: 2009-4-27 13:11 标题: EN 71-1:2005/prA8:2008 EN 71-1:2005/prA8:2008作者: eastnan 时间: 2009-4-27 17:33
为什么内容不全呢？作者: DOCTORO 时间: 2009-4-28 00:01
内容不全的话意义不大作者: brian3439 时间: 2009-4-29 23:14
PR A8主要内容 / U4 N4 Y6 m5 {6 O& g6 k . l9 y& J% l. L: b0 A' x) A, y* I* f& ~0 N x4 C9 M w4 L( X( m) p
+ v9 P; _6 w7 \9 }- \
p- I! s* T; U$ m3 Y0 VEN 71-1:2005/prA8:2008 (E) 5 z& D1 S: c9 O1 L j2# U* G) K1 I- A0 z) f( l
Contents Page 4 L, L: Y/ F) j" d d% LForeword.............................................................................................................................................................3 1 L8 e7 c' Q; a1 K) A3 Terms and definitions ...........................................................................................................................4 ; b( ^5 B1 q1 Z- ^4.23 Magnets (see A.51) ...............................................................................................................................4- K1 y) N$ Y, {' d L. h
4.23.1 General...................................................................................................................................................4 $ v# u$ n/ x5 ?# w7 f, @4.23.2 Toys other than magnetic/electrical experimental sets.....................................................................4; d% p. A- U& ?' G& I( R
4.23.3 Magnetic/electrical experimental sets .................................................................................................4 ; P2 q" {2 |& n2 z; s. _7.20 Magnetic/electrical experimental sets (see 4.23 and A.51) ...............................................................5 : t5 V7 M+ ^* k0 X. J# M8.34 Tension test for magnets (see A.51)....................................................................................................58 D& k% Q; b; `/ }# j' W9 `9 k
8.34.1 Principle.................................................................................................................................................5; h0 f+ F& ~9 Y7 R
8.34.2 Toys that contain more than one magnet or magnetic component .................................................5 # D9 m' X; I! \5 T- @2 ]3 N6 {8.34.3 Toys that contain one magnet only .....................................................................................................5 3 K. Y8 `1 B9 ^) S8.35 Magnetic flux index...............................................................................................................................6+ n" u# }3 N& [ Y2 y% E
8.35.1 Principle.................................................................................................................................................6 & [4 @; P$ o7 q8.35.2 Apparatus ..............................................................................................................................................6 z2 t& u) @' r* R6 X- A7 d0 |7 z
8.35.3 Procedure ..............................................................................................................................................6 * o9 Z$ q; j9 F! O8 ]6 J8.35.4 Calculation of magnetic flux index ......................................................................................................6% Z/ G9 M" i) c/ |3 J [. f
A.51 Magnets (see 4.23)................................................................................................................................7" V6 v$ |8 x% F* g+ z
EN 71-1:2005/prA8:2008 (E): O5 T/ a. \5 J( Q/ O6 G S |0 a
Foreword + u& K- p' c8 O/ g0 p3 v" t) F) uThis document EN 71-1:2005/prA8:2008 has been prepared by Technical Committee CEN/TC 52 “Safety of1 T1 |2 Q/ Q7 O
toys”, the secretariat of which is held by DS. 1 z4 |5 a2 f0 A; `This document is currently submitted to the Unique Acceptance Procedure.: ~9 ~5 S+ ?, I1 r4 I
This document has been prepared under a mandate given to CEN by the European Commission and the" o( f1 {& U6 P1 z1 `
European Free Trade Association, and supports essential requirements of EU Directive(s). r9 x% T, i9 E" eFor relationship with EU Directive(s), see informative Annex ZA, which is an integral part of this document./ K2 d- |2 y& @! ~
EN 71-1:2005/prA8:2008 (E) ) A" D( \' w/ D6 R9 `4 " T6 g+ D& N& o3 Terms and definitions 7 A) G4 d: F& J; }5 }3 MAdd new definitions:3 q: z: R1 R: z4 e
3.xx 6 Y# l/ ?& Q9 l- |2 lmagnetic component2 T, T( N b! \1 _# D1 C4 s
any part of a toy which contains an attached or fully or partially enclosed magnet* d$ ]9 v3 o: ]& [% v5 J
3.yy$ ]+ h' F/ B6 i R9 M/ f8 w
magnetic/electrical experimental set ; Y h7 l% ~2 ^* p( T3 A& atoy containing one or more magnets intended for carrying out educational experiments involving magnetism : _1 i. [1 C% E( C% _4 _+ Oand electricity ; s8 H2 H: Q$ Z( J$ }NOTE - This definition does not include magnetic/electrical experimental sets in which all magnets have a magnetic flux 8 A, ^6 s, b$ w# X m4 ]$ Nindex less than 50 kG2mm2 (0,5 T2mm2) when tested according to 8.35 (magnetic flux index), or do not fit entirely in the 5 u+ Q& O1 E, I0 C4 Ccylinder when tested according to 8.2 (small parts cylinder)3 U4 N' o0 {" n/ y
3.zz/ p4 B# _3 H& l" ?9 U' w
functional magnet in electrical or electronic components of toys 4 X; h7 P' r( j2 A- O' Aany magnet necessary for the function of motors, relays, speakers and other electrical or electronic ! e/ `6 |7 a& H$ u0 Y0 |+ d$ S' Lcomponents in a toy where the magnetic properties are not part of the play pattern of the toy 5 J2 ^" v7 s1 `) P, W$ q4 R# d' {Add new clauses:, K5 d1 l0 C! u) ~1 e
4.23 Magnets (see A.51)0 }, P8 p( y* n6 I9 q
4.23.1 General - c) Y) `7 B/ G( nThe requirements in 4.23.2 do not apply to functional magnets in electrical or electronic components of toys. 9 [) X G( A& Q" X% s0 P$ W; L4.23.2 Toys other than magnetic/electrical experimental sets" X$ C1 \$ r( R2 G; k2 \
a) Any loose as-received magnet(s) and magnetic component(s) shall either have a magnetic flux index; }, T M1 K$ t' z& v+ s& ?
less than 50 kG2mm2 (0,5 T2mm2) when tested according to 8.35 (magnetic flux index), or shall not fit* n- ]6 P% K/ H% g# j* [6 A5 B b
entirely in the cylinder when tested according to 8.2 (small parts cylinder). 7 ^/ N6 W K2 yb) Any magnet(s) and magnetic component(s) that become(s) released from a toy when tested( E+ o3 j, T: m1 D' i5 E8 _' I
according to 8.3 (torque test), 8.4.2.1 (tension test, general), 8.4.2.2 (tension test, seams and# @; ?; ~1 b" M2 c4 D
materials), 8.5 (drop test), 8.7 (impact test), 8.8 (compression test), and finally, for magnets that are / `; c) Z1 k0 W+ k) [& l8 ?5 haccessible but not grippable (as specified in 8.4.1.3), 8.34 (tension test for magnets), shall either have 5 w. X5 ~2 D# aa magnetic flux index less than 50 kG2mm2 (0,5 T2mm2) when tested according to 8.35 (magnetic flux 6 d' h8 s; [2 o& kindex), or shall not fit entirely in the cylinder when tested according to 8.2 (small parts cylinder). " d0 Y4 x3 _2 |1 I; e5 s6 iNOTE – An example of a magnet that is accessible but not grippable could be a magnet that is recessed. . `0 J) ^$ x( }* Q7 bc) Wooden toys, toys intended to be used in water, and mouth-actuated toys shall be tested according to! D! V5 d1 w4 B" R
8.9 (soaking test) before being tested according to 4.23.2 b) above.8 ~! V* j+ |0 ]7 m" ?& K
4.23.3 Magnetic/electrical experimental sets \2 T L3 L8 O3 q0 U o5 _9 Z. XMagnetic/electrical experimental sets intended for children over 8 years shall carry a warning (see 7.20). 8 {6 E/ g6 c6 W# f/ Z2 M. _EN 71-1:2005/prA8:2008 (E) : [. x- v, K: ~2 R2 MAdd a new clause:. d6 h& c/ H1 o' v8 o. j- C% m4 \$ b; p
7.20 Magnetic/electrical experimental sets (see 4.23 and A.51)' I' y, M# A6 E3 l7 L8 y
The packaging and the instructions for use of magnetic/electrical experimental sets shall carry the following' F9 n2 i: p0 o+ x! V# c! P
warning: ) O* `+ s/ l( w“WARNING! Not suitable for children under 8 years. This product contains (a) small magnets(s). $ d/ N* ^& l$ b, ~: Y: j6 k/ b. cSwallowed magnets can stick together across intestines causing serious injuries. Seek immediate 1 r; B: ]' `; _1 w/ S5 l! Z+ I0 ~/ @medical attention if magnet(s) are swallowed”. + ~$ f+ [' q( M" c* G4 nAdd new clauses: ' ?8 ?! N: g3 k8.34 Tension test for magnets (see A.51)& o; C0 K8 Y( {$ Y' U9 C4 n, b# C
8.34.1 Principle 2 f; O' Z! K& K K- H0 EEither a magnet or a magnetic component, or a reference disc, is used in order to test whether an accessible8 b( S9 r) r5 X, E# {
but not grippable magnet in the toy can be detached by a magnetic pulling force.' Q; M$ J" q# |6 o9 ^
The test shall simulate the intended or a reasonably foreseeable play pattern.. i' [/ Q. b- z# Z; C
8.34.2 Toys that contain more than one magnet or magnetic component$ p; I. c$ z' ^3 q' h
Identify the magnet or magnetic component in the toy that is most likely to be able to detach the magnet that is; }& e! V) J: _8 _
to be subjected to the tension test., c! ]* m7 k8 o: i1 R
Without damaging the toy, place the magnet or magnetic component as close as possible to the magnet to be4 w8 ?" L) F3 J& T7 @+ y, a' n
tested. Gradually apply a pulling force to the magnet/magnetic component until it separates from the tested ' k! X3 b7 X+ F( `2 S9 nmagnet or until the magnet is detached from the toy. Perform the test 10 times.1 M6 k. n/ L* N# N ] a
Repeat the procedure for any other magnet that according to 4.23.2 shall be subjected to the tension test for * [* }" c/ w s B4 z: f, i/ }magnets. ' e: N# Q! K: A8 kNOTE – If it is not possible to determine which magnet or magnetic component(s) in the toy that is most likely to be able to 2 W; _4 t q1 M8 Mdetach the magnet that is to be subjected to the test, it is permissible to repeat the test with another magnet or magnetic 2 v/ a5 ~8 ^6 K, t$ W0 kcomponent from the toy.7 C" v/ l* {4 I+ d
8.34.3 Toys that contain one magnet only 3 w+ H; |% m- ~8.34.3.1 Apparatus ( y. t8 F* t: X+ h# B+ {8 R5 F; u' YA nickel disc with a minimum nickel content of 99 %, and having the following minimum dimensions: ' i; P: T- q; m2 a$ p; Y% O- diameter (30 ± 0,5) mm+ e# D8 F7 N( U
- length (10 ± 0,5) mm ! a1 h3 H7 v" S) T7 D! X0 \4 \5 nand having a surface roughness Ra according to EN ISO 4287 which is not greater than 0,40 μm. . e6 p0 f1 j( N5 a. r) J+ B8.34.3.2 Procedure # T8 }) I9 w6 ^7 Z0 l- S X9 P' kWithout damaging the toy, place the flat part of the nickel disc as close as possible to the magnet to be tested. 9 Y; L- `/ X" R% N9 ?% ^) LGradually apply a pulling force to the disc until it separates from the magnet or until the magnet is detached0 a" ^! @( {( J- {4 G, e- t' q1 ]
from the toy. Perform the test 10 times.* ^4 R& y5 a0 K
EN 71-1:2005/prA8:2008 (E) ' d$ J: [8 H# R2 W6 # _# i. g3 D9 h! U8.35 Magnetic flux index, {" _8 A6 |! M1 s+ t( B5 j F3 [; f
8.35.1 Principle3 n- G1 J3 J) R1 p" C8 m
The magnetic flux index is calculated based on the results from measurements of the flux density and the pole , A% R0 w- j7 L" k J6 L asurface area. # r$ y* p5 L+ d! R1 _1 T8.35.2 Apparatus $ {0 i+ ^- P* C( r' g. T8.35.2.1 Direct current field Gauss meter which is capable of determining the field to an accuracy of 5 G.9 \" N* i! k4 y l7 b* P2 S# o/ s
The meter shall have an axial type probe with 0 t( y+ M/ ~ U- \! H& l7 J- an active area diameter of (0,76 ± 0,13) mm , [3 W$ ?1 \' _$ j* t- a distance between the active area and probe tip of (0,38 ± 0,13) mm.; j0 S' F E6 v
8.35.2.2 Calliper square or similar device capable of determining dimensions to an accuracy of 0,1 mm. $ V/ }) S# X( i" b4 G; C) O8.35.3 Procedure. P O' ?3 ]4 q( z: P. ^
8.35.3.1 Measurement of flux density( X y5 r, M: B. T: h0 Y
Place the tip of the Gauss meter’s probe in contact with the pole surface of the magnet. For a magnetic + h2 S: L! m5 u0 H3 h, r+ V8 X$ ucomponent (where the magnet is fully or partially imbedded in part of the toy), place the tip of the probe in 4 p2 b B2 ?6 j. \# Rcontact with the surface of the component.# r7 Z6 K) V2 C @. ~! P. R
Maintain the probe in a position perpendicular to the surface. 7 G% J6 d2 y: B# w) DMove the probe across the surface to locate the maximum flux density. : u$ a& s3 H1 i1 y5 NRecord the maximum flux density with an accuracy of ± 5 G. ) r( G: i8 a7 b2 O3 ^7 E& a8.35.3.2 Measurement and calculation of the pole surface area! q; R! ?; x# ]# q+ ?8 w3 M
If the magnet is imbedded/attached as part of a magnetic component, extract the magnet from the component 6 B* `- y' R, Y5 deven if it is necessary to break the toy. / x# [7 J: r8 S9 c: T9 K# IIf the pole is not flat (for example, hemispherical), measure the maximum diameter of the magnet 2 R- v) X; C }- uperpendicular to an axis through the magnet poles (see Figure xx), with an accuracy of ± 0,1 mm and" ]. y% u5 H. H% ~- ^
calculate the area of the corresponding cross-section. * h! ^' _$ ^6 \$ g0 _: ~If the pole surface of the magnet is flat, measure the dimensions with an accuracy of ± 0,1 mm and calculate' ^8 U) x# e( M; u, H7 w7 F, x) ]3 ?
the area using the appropriate geometric formula. / N$ U* F+ h) f; PFor multi-pole magnets measure and calculate the area of the largest single pole, which can be identified ! m1 p* o9 ~6 busing magnetic field viewing film or equivalent." v( |. x" X1 i! z. ^4 `
NOTE – An example of multi-pole magnet is a rubberized/plastoferrite magnet, consisting of multiple strips of ! y# ~ T) m5 k f- Mpoles. , ^+ k- x5 ?+ p# G6 u* O. k ]8.35.4 Calculation of magnetic flux index) u9 P* O2 a% B" J- d/ I/ J% W* F
The flux index (kG2 6 T' r3 v$ r; Y( wmm2) is calculated by multiplying the calculated area of the pole surface (mm2) of the 9 P6 }% ]$ }/ K1 I0 emagnet by the square of the maximum flux density (kG2).! V5 I6 p6 _+ F5 I, c
EN 71-1:2005/prA8:2008 (E)3 N. D# Z# R5 f/ X; {
Key: d8 C- W, {7 a. B V1 w. G
1 Maximum cross-section perpendicular to the axis * h% u; G" |1 q/ n) }/ ~. F' Z2 W2 Axis through the magnet poles7 t- t% ]' [7 T" ]1 T
Figure xx – Maximum diameter of magnet with a non-flat pole 8 J3 B0 p$ ^& G4 h8 |8 @ g1 q" WAdd new clause in Annex A3 x% {3 D6 u* A7 i+ J1 @
A.51 Magnets (see 4.23)6 B" j X( b, S5 X* Y
These requirements are intended to address the hazards associated with ingestion of strong magnets (e.g.: E" |+ V* w. M7 J X% W5 w
neodymium iron boron type magnets), that are capable of causing intestinal perforation or blockage. These ( x9 c8 ]0 M3 r# @" p& ~hazards are additional to those associated with small parts such as suffocation or asphyxiation (see A.26).9 J9 j4 `+ s, u- ~, E# F2 \7 Q
The requirements apply regardless of the intended age of the user. # k$ i: m" S2 M, y- ^Magnets found by children can be ingested. If more than one magnet, or one magnet and a ferromagnetic 9 [/ l5 z+ L4 j8 Uobject (for example iron or nickel) is ingested, the objects can attract to each other across intestinal walls and7 V9 n* e9 N5 u8 \: K9 e1 w g! Q
cause perforation or blockage, which can cause severe injuries that may be fatal.0 z% Q7 }2 r! R& N# L' V( H
Several accidents, including one fatality, have been reported involving ingestion of magnets resulting in1 S7 B4 w7 p# N
perforation or blockage of the intestines. Most accidents have occurred with children between the ages of 105 Z5 ^9 O9 W8 q5 |) y( U) w. W7 a
months and 8 years. The majority of the accidents involve strong magnets used in magnetic building sets and ! b/ ]0 R! t7 m8 C# d/ H+ }! uin several cases surgery was required to remove the magnets from children’s intestines. Medical signs 5 v6 [) R' Y, ^+ H2 }( [( Eassociated with intestinal perforation or blockage can easily be misinterpreted since many children exhibit only( p3 p) `- q$ G* o
flu-like symptoms. : D5 Y; m" T% y, QFor the purpose of this standard, magnets or magnetic components that could be ingested are identified by : p4 h* \1 z$ W) E: T( Husing the small parts cylinder. The small parts cylinder was originally designed for identification of small parts 7 _ a7 R" P- H l" _1 e2 ~6 }in toys intended for children under 3 years, which are capable of causing suffocation or asphyxiation. It was 7 N, P5 q6 d+ g, C% Mnot designed for identifying objects that can be ingested by older children. The decision to use the small parts & x0 J' T9 r! @( s2 dcylinder also for assessment of magnets or magnetic components that can be ingested was made for practical , \4 j4 x* {( ~& v8 T7 ~3 i& H, H, Hand precautionary reasons: The cylinder is a well known test template and it provides a safety margin since) {2 q- `6 d' b+ T- l. x8 f% m
the magnets and magnetic components that have caused accidents all fit entirely in the cylinder with a large ) y4 Q4 g( u7 X, zmargin. The same principle has been applied in the requirements for expanding material.8 P/ E! W8 M) L/ p9 }+ T
The risk of magnets attracting each other across intestinal walls is reduced with decreasing magnet strength.9 ^) K+ t6 p) t( k/ r: x
A limit value in the form of a magnetic flux index has therefore been introduced to define what a sufficiently * f# S7 M: `; Y8 K jweak magnet is. Accident data indicate that only powerful magnets have been involved in all known ingestion/ s: W7 r5 J2 z
incidents to date. The data also suggest that magnet ingestion was not a problem in toys until powerful( R1 X2 y; c$ p
EN 71-1:2005/prA8:2008 (E)$ _4 `8 ^; g* V6 n. \4 j9 I2 L
8 $ c6 D! j, U3 x# J3 _) `magnets (such as neodymium iron boron magnets) became cost effective and commonplace several years7 z+ p% d: s+ v0 S, L( _
ago. Ceramic, rubberized, and ferrite magnets have substantially lower attractive forces. A limit value for the . U3 O! {; M$ L9 Q5 R" O8 I: G, hmagnetic flux index of 50 kG2mm2 (0,5 T2mm2) is considered appropriate to ensure, with a safety margin, that% W, E" J! r' v- H" f
powerful magnets of the type that have been involved in incidents will not be permitted for use in toys if they fit: u5 u3 O7 n/ j$ j5 l- @ J* m! [
entirely in the small parts cylinder. The one known fatality occurred with a magnet from a magnetic building! p8 v! \5 l6 O$ C' B1 s+ R+ y& v
set with a flux index of 343 kG2mm2 (3,4 T2mm2). By introducing the flux index limit the risk of injuries with - t" c+ s5 C0 N# R% w$ t4 Jmagnets has been minimised. New data in the future will be used to assess if the chosen requirements are 4 k- \2 I; K3 x# n. R3 P7 Wstill appropriate. % x3 [/ k) {3 Y1 d# a# V3 m! JMore than 80 % of the known accidents have occurred with magnetic building sets. Magnetic building sets are/ s5 m! @, W4 J( Y6 S3 m, h
subject to the requirements in this standard.9 G0 Q& D' X. f/ B3 d( {, m. c
Other considerations were taken into account in evaluating the risks associated with ingestion of magnets. . z' K. ^7 f7 X" P; fPerforation of intestinal walls can occur if the blood supply to a part of an intestinal wall is cut off, for example8 ^$ _/ v: d% |7 Q. H
by the pressure exerted by two magnets that are attracted to each other across the walls. According to a $ ^8 T# ^$ V Etheoretical medical study, a pressure of 0,0016 N/mm2 (12 mmHg) could, in a worst-case situation, cause ( g! G5 p6 g' q' u9 ~$ Y. j/ ssuch a cut off of the blood supply. Virtually all magnets on the market are capable of producing this level of, }- j8 u" L3 ^
pressure.8 e( [! p8 S v8 K2 ]* G
The probability that two weak magnets (flux index below 50) will be transported through the intestinal system. o" L$ S) M; n9 Z3 p Q$ k( c
and end up on opposite sides of the intestinal walls at a position where the intestinal wall is extremely thin is & y6 P7 q1 V6 r5 t* Sconsidered to be very low. It would require not only that the two magnets are ingested on different occasions * e1 S! J) z {& \but also that the intestinal contents do not prevent the magnets from travelling along the walls and eventually, y3 k- u# n- {) n
finding each other on opposite sides of two walls by accident. For strong magnets the situation is different,, G- d( A9 O5 D0 c1 e( n
since they attract each other over a longer distance with a force than can overcome obstructions presented by 1 I$ C8 l& e6 F% f" A- Y, X8 ye.g. intestinal contents. 9 o- J/ C8 a" @- S$ g9 j( {Furthermore, for a correct calculation of the magnetic pressure, both the flux density and the contact area* Z( `4 g) H# E% P d, O; S# w
need to be measured. The formula to calculate magnetic pressure is: * ~6 X0 o* W! T& x3 N0 n( Q& NAc 1 [& o4 o( y2 n7 m/ F6 W( x6 h4 ^P Ap ⋅ ⋅9 m' l q M3 Q4 {5 w. @ S
= : V( l, ~+ h0 jα B2, |8 V8 v- m6 z. W
where 1 p O/ R* j# J3 {. ?P is the pressure $ i f2 d. P4 s8 tα is a constant" |. u8 j, r0 J/ c- H
B is the Flux density (in Gauss or Tesla), and ' w" b1 `& P# h3 N5 ^Ap is the pole area of the magnet ' u7 N. O! T, D6 a2 L* k$ L. LAc is the contact area between the magnet and whatever surface the magnet exerts the pressure on 8 K7 C" K3 w) p- H% s4 }2 q6 BThe contact area between a magnet or a magnetic component and the object to which it is attracted, is often; t! Y7 ~7 I5 y) ^
very difficult to measure accurately due to unevenly shaped magnets or magnetic components. + j9 `4 w/ k3 h. p. m0 k9 jThe flux index, however, can be calculated using the pole area of the magnet and the flux density at the+ k, T& L3 E5 Q7 L3 }
surface of the magnet or magnetic component. The flux index is therefore presently considered to be the best 2 q9 Z8 h% J& }9 e1 tavailable measure for classification of hazardous magnets. 3 q4 d0 D8 g: J$ F, f- A* {Two or more magnets can attract each other and form a compound magnet with a higher flux index than each0 n0 u+ R; F1 v% T
single magnet. The flux index will not double if two equally strong magnets are attracted to each other and the1 t9 D* K' o6 W- V& z' p- L; m( t- ]
increase in flux index will be relatively smaller for every new magnet that is added and will depend on5 `4 H1 R' B' m0 d
magnetic material, shape, cross-section etc. Ingestion of multiple magnets has only been observed with 0 W9 `: E; [& Y& f/ Pstronger magnets and there is no accident data regarding weak magnets close to the flux index limit forming a3 P6 v2 j- t; P Z \/ b7 ?
(stronger) compound magnet. Therefore no additional test method for compound magnets is introduced.; T6 U; g. R; }
Toys that contain magnets and which can be expected to become wet during normal and foreseeable use are" }% y1 s; ?, s3 _7 h
subjected to a soaking test to ensure that glued magnets do not detach when the toy is wet. Also wooden toys 1 p. m2 p# Z9 b: W, `; v7 N+ u pEN 71-1:2005/prA8:2008 (E) ) t$ _1 \( u/ a t* S. Jare subjected to the test since the properties of wood (such as size of holes) can change even with changes in1 e1 `5 \* l5 A9 W1 u
air humidity. $ w% t) d# m3 RIn some cases magnets are recessed and can therefore not be subjected to the normal tension and torque , ^7 s- n0 ] |0 v, ]4 Itest. Examples of toys have been found where a magnet has become detached by another magnet. A tension e; d6 _3 H- S# B+ J: w z% e" vtest for magnets has therefore been introduced to minimize the risk that such magnets become detached 9 d' U, ^! g/ j: \; vduring normal and foreseeable play. " g9 ]) O5 G, ~( o: ?Functional magnets in electrical or electronic components of toys are not considered to present the same risk 3 w7 w# u5 P; F$ F @5 Oas magnets that form part of the play pattern. The use of magnets in these components may not be% y* ]- K' ?+ s. f
recognized, as they will be present inside electrical motors or in relays in electronic printing boards. None of6 \7 O$ f; ~" ~; j8 z; z7 f
the reported accidents has been linked to magnets released from electrical or electronic components 8 K ~! |+ @3 |' O0 H! `, u* ZMagnetic/electrical experimental sets that are not intended for children under 8 years are excluded from the ( o1 q; D6 R$ k ^( Vrequirements provided that they carry a warning. The exception applies only to the more advanced7 M3 q* y- x/ u* M: i8 u
experimental sets that include building of electrical motors, loudspeakers, doorbells etc., i.e. products that ( A, p8 |5 d* x8 |% tneed both magnetism and electricity for their function.作者: muhong 时间: 2009-4-30 09:10
是啊有没有PDF格式的标准呀？共享下咯~作者: runty 时间: 2009-4-30 10:09
要好好看看又有什么新名堂作者: stephen_2009 时间: 2009-5-4 15:34
什么新名堂？？？？？？？？作者: eastnan 时间: 2009-5-4 16:44
请问最新的版本什么时候发布呢？