g]=u'0f.५५० :२०७५  
                                                                               N.S: 550:2075  
                                                   
                                                                                         
 
                                                                    
 
 
 
    
g]kfn u'0f:t/                                                                                        
NEPAL STANDARD  
PROTECTIVE HELMETS FOR MOTORCYCLE RIDERS –SPECIFICATION  
 
  
 
 
 
 
 
 
 
g]kfn ;/sf/                                                                                                                        
pBf]u बाणिज्य  तथा आपूणति मन्त्रालय                                                                               
g]kfn u'0f:t/ tyf gfktf}n ljefu  
फाराजु, काठभाडौं  
 
  
g]kfn u'0f:t/ kl/ifb \ 
Nepal Council for Standardization (NCS)  
 
 
अध्यऺ 
भानननम भात्रिका मादफ , उधोग फाणिज्म तथा आऩूनति भन्त्िी  
उपाध्यऺ  
  श्री माभ कुभायी खनतवडा, सचिव , उद्मोग , फाणिज्म तथा आऩूनति भन्त्िारम 
सदस्यहरु 
l;=g+=       gfd                                        ऩद                             ;+:yf 
१ श्री zq'wg k|;fb k'8f;}gL             सह सचिव      उद्मोग , फाणिज्म तथा आऩूनति भन्त्िारम 
२ श्री   ...................                        सह सचिव    उद्मोग , फाणिज्म तथा आऩूनति भन्त्िारम 
३ श्री सुयेन्त्र ऩसाद सुवेदी         सह सचिव     शिऺा, ववऻान तथा प्रववचध भन्त्िारम  
४ श्री संजीव कुभाय किि           सहसचिव     कृवि ववकास भन्त्िारम (खाध प्रववचध तथा गुि 
ननमन्त्िि वव .) 
५ श्री ननभिरा अचधकायी बट्टयाई      सह सचिव    कानुन तथा संसदीम भाशभरा भन्त्िारम  
६ श्री रयकेि  भहजिन       इन्न्त्जननमय ( प्रनतननचध सदतम)  बौनतक ऩुवािधाय तथा मातामात व्मवतथा भ  
७ श्री सुभनरार श्रेष्ठ              प्राध्माऩक             त्रिबुवन ववश्वववधारम   
८  श्री प्रा.डा. ददऩक सुफेदी                              काठभांडौ ववश्वववधारम      
९  श्री ददनेि  श्रेष्ठ                                      नेऩार उधोग वाणिज्म भहासंघ         
१० श्री ददऩक श्रेष्ठ                                       नेऩार िेम्वय अप कभसि  
११  श्री अननता जोिी                               उऩबोक्ता सयोकायवारा संघ संतथा  
१२  श्री शस जिना फुरािकोटी                               उऩबोक्ता सयोकायवारा संघ संतथा  
१३  श्री अरुिदेव बट्टयाई                                 ववऻ  
 
 
सदतम सचिव  
श्री ववश्ववाफु ऩुडासैनी, भहाननदेिक,ने.गु.तथा ना.त्रफ.हेल्भेट ;DalGw k|fljlws ;ldltsf] ;b:ox?  
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२०.श्री कृष्ि फहादुय सोडायी,ने.गु तथा ना.त्रफ 
  
 
प्रततावना  
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k|n]v tyf  ;fwfgsf] ;xof]u lnPsf] 5.   
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 v_jL=P;= cfO{   la|l6z :6f08{8 OlG:6 Ro';g 
 u_jL= cfO=P;=    Jo \/f] ckm Ol8of :6f088{  
 ३. k|n]v tof/  kfbf{ vf; Wofgdf /flvPsf फुदाहरु 
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of] u'0f:t/  k|n]v tof/  kfg]{ sf]lz;  u/LPsf]  5. sy+bflrt u'0f:t/  k|n]vsf] s'g} efudf pn]lvt s'/fx?  Xfn k|rngdf  
ePsf tyf eljiodf  cfpg]  P] g lgod ;Fu aflemg  uPdf To:tf -k|n]v_sf s'/fx? :jt lgis[o x'g]5  . 
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dfGotf  lbO{  lolgx/sf] k|of]u ul/Psf] 5.  
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tyf u'0f:t/ lgwf{/0f / u'0f  ननमन्त्िि ;DaGwL  c?  sfo{x?sf]  k|ltj]bg  OToflbaf6  ;fdfu|Lx? Oyf;Dej k|fKt u/L 
ltlgx?sf] l;kmfl/; cg'?k ;fdGh:otf Nofpg vf]lhPsf] 5.  
#=% o; k|n]vsf] th{'df  ubf{ gfktf}n OToflb ljleGg  OsfOx?sf] nflu cGt/f{li6«o  If]qdf  rln/x]sf] jx'dfGo OsfO{ ty  
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$=  o; u'0f:t/ k|n]vdf  pNn]lvt cfjZstfx?  cg'?k  5 jf 5}g eGg] s'/f lglZrt ug]{ ul/Psf]  k/LIf0f  jf ljZn]if0fsf]  
glthf k|:t't ug{ ;+:yfx?nfO{ /fplG8‹ ckm ubf{ g]u'0f g=!& cg';f/ ul/g' kb{5.  
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If]q leq kb{}g.  
 
 Nepal Standard  
 
PROTECTIVE HELMETS FOR MOTORCYCLE  
RIDERS –SPECIFICATION  
1 SCOPE  
1.1 This standard  lays down the requirements  regarding  materials , construction, workmanship , finish,  
mass and  performance  for protective helmets (with  or without lower face cover)  for everyday use 
by motorcycle riders.  
1.2 The helmets covered by this standard are not intended for high speed competitive events.  
 
2 REFERENCES  
The Nepal standard listed in Annex A are necessary adjuncts to this standard.  
 
3 TERMINOLOGY  
For the purpose of this standard, the following definitions shall apply (see Fig. 1)  
3.1 Motorcycle  
A two wheeled motor vehicle, inclusive of any detachable side car having an extra wheel, attached 
to the motor vehicle.  
3.2 Protective Helmet  
A helmet p rimarily intended to protect the wearer's head against impact.  
3.3 Shell  
The hard part of the protective helmet which gives it its general shape.  
3.4 Protective Padding  
A material used to absorb impact energy.  
3.5 Comfort Padding  
A material provided for the wearer’s  comfort.  
3.6 Retention System  
The complete assembly by means of which the helmet is maintained in position on the head, 
including any devices for adjustment of the system or to enhance the wearer’s comfort.  
 3.6.1  Headband  
      Part of retention sy stem in contact with and surrounding the head.  
3.6.2 Chin strap  
A part of the retention system consisting of a strap that passes under the wearer’s jaws to keep the 
helmet in position.  
 
  
 
3.7 Peak  
It is an extension of the shell above the eyes.  
3.8 lower Face Cover  
A detachable or integral part of the helmet covering the lower part of the face.  
3.9 Visor  
A transparent protective screen extending over the eyes  and covering part of the face.  
3.10 Goggles  
Transparent protectors that enclose and cover the eyes.  
3.11 Basic Plane of the Human Head  
A plane at the lev el of the opening of the exter nal auditory meatus (external  ear opening)  and the lower 
edge of the orbits (lower  edge of the eye sockets) .  
3.12 Basic Plane of the Headform  
A plane which corresponds to the basic plane of the human head.  
 
3.13 Central Vertical Axis  
The line relative to human head or headform or helmet that lies in the plane of symmetry, and that is 
normal to the basic plane at a point equidistant from the front and back of the head Of the headform or 
(for helmet) of the headform that simulates the head that the helmet is intended to fit ( Fig. 3B ),  
3.14 Reference plane  
A construction plane parallel to the basic plane of the hea dform at a distance from it which is a function 
of the size of the headform.  
3.15 Neek Curtain  
A part of the helmet attached to the lower edge of the helmet designed to protect against adverse 
weather conditions, dirt and small  stones,  
 
4 MATERIAL  
4.1 Shell  
The shel l of the helmet shall be of non -metallic  materials conforming to t he test requirements given in 
4.5 and 9.1.  
4.2 Protective Padding  
It shall be of expanded polystyrene or any other material having similar properties.  
4.3 Comfort Paddin g 
It shall be of expanded polyurethane  foam, polyethylene or any other suitable material having similar 
properties.  
4.4 Retention System  
The criteria for selection of material for chin strap and headband shall be sweat -resistant , non- Irritant 
and shall n ot be known to cause skin disease.  
4.5 Metal  Parts  
The metal par ts in helmet shall be either inherently corrosion  resistant  or shall have been treated  for 
corrosion resistance. Such pans shall show no sign of corrosion when subje cted to test as specified in 
NS1** …..  
4.6 Visor  
The criteria for selection of material for visor, if provided, shall be in accordance with NS2**.. .  
5 SIZES  
5.1 Helmets  shall be of the sizes matching to the sizes  of headform of 500, 510, 520, 530, 540, 550, 560, 
570, 580, 590, 600, 610, 620, 630 and 640 mm in accordance with  NS3** ….  
6 CONSTRUCTION REQUIREMENTS   
6.1 General   
6.1.1  The basic construction of the helmet shall be in the form of a hard outer shell containing additional 
means of absorbing impact energy and a retention system.  
6.1.2 The protective helmet may be fitted with ear fl aps and a n eck curtain. It may also have a 
detachable peak, a visor and may also have a lower face cover.  6.1.3  No component  or device shall be fitted  to or incorporated in the protective helmet unless it ii 
designed in  such a w ay that it shall not cause injury  and that, when it is fitted to or inco rporated in the 
protective helmet, the helmet still complies with the requirements of this standard.  
6.1.4  The characteristics of the materials used in the manufacture of helmets shall be known not to 
undergo appreciable alteration under the influence of ageing , or of the circumstances of use to which 
the helmet is normally subjected, such as exposure to sun, extremes of temperature and rain. For those 
parts of the helmet coming into contact with the skin, the materials used should be known not to 
undergo appreciable alteration through the effect of perspiration or of toilet preparations. The materials 
known to cause skin troubles should not be used.  
6.2 Shell  
The extent of the protection provided shall be as given in 6.2.1 to 6.2.7.  
6.2.1  The shell shal l cover all areas above plane A A and shall extend downwards at least as far as the 
lines CDEF on both sides on the head - form ( see Fig. 2A ),  
6.2.2  At the rear,  the rigid parts and» in parti cular, the shell shall not be within a cylinder of diameter 
100 mm, w ith axis situated at the inter section of the medium plane of symmetry of the headform and of 
a plane parallel to and 1 10 mm below the reference plane ( see Fig. 2B ),  
6.2.3  The helmet shall not dangerously affect the wearer’ s ability to hear and shall conform to the 
requirements laid down m 9.5. Ventilation may be provided for increasin g the comfort of the rider. The 
outer surface shall be perfectly smooth. Above the reference plane, the shape shall be in the form of a 
contin uous, convex curve, except where shaping is provided for functional purposes. Below the 
reference plane, irregularities in the curve shall be smoothly faired. The shell shall not incorporate an 
integral peak, but may incorporate in integral lower face cove r. Where means for attaching a visor are 
not provided, the profile at the front edge shall not prevent the wearing of goggles.  
6.2.4  There shall be no external projections greater than 5 mm above the outer surface of the shell. 
Where a goggle fitting is p rovided at the rear of the helmet and is designed to be detach - able, this 
requirement shall not apply to such a fitting.  
6.2.5  Any external projections other than press - fasteners shall be smooth and adequately faired. Rivet 
heads shall  be radiused and s hall not pro ject more than 2 mm above the outer surface of the shell.  
6.2.6  There  shall be no inward -facing sharp edges o n the inside of the helmet. Rigid project ing internal 
parts shall be covered with padding so that any stresses transmitted to the head  are not highly 
concentrated. Rivet heads shall be radiused and shall not project more than 2 mm above the internal 
surface of the shell.  
6.2.7  The components of the helmet which are intended to protect the head of the user shall be 
assembled such that th ey may not become easily detached or move under the conditions of the test as 
specified in 9.1.  
6.3 Protective Padding  
The protective padding shall cover all the areas defined in 6.2.1 t aking into account the require ments 
given in 6.2.3.  
6.4 Retention S ystem  
The helmet shall  be held in place on the wearer's head by means of a retention system which is secured 
under the lower jaw and is firmly attach ed to the shell.  
6.4.1  Chin Strap  The strap shall not be less than 20 mm wide under a load of (150  N ± 5) N applied under the conditions 
given in F -1.2.  
6.4.2  The chin strap shall not include a chin cup.  
6.4.3  The device to open the retention system shall not be capable of opening other than as a result of a 
deliberate act. In the case of a press - fastener  opening device, the press - fastener shall be recessed, that 
is. the surface to which the pressure is applied shall be fitted with a fairing a bout its whole periphery so 
that opening docs not occur when the surface is pressed with a sphere of 100 mm diamet er. 
6.4.4  The retention of the helmet on the head by the retention system shall be verified when the test 
described in 9.6 is carried out. When a helmet subject to the test shall be that present ing the least 
favorable  conditions (such  as the thickest paddi ng, etc .).  
6.5 Peripheral Vision  
6.5.1 The helmet shall be placed on the head, form (see NS3**… ) corresponding to its size by the 
procedure as specified in Annex B.  
6.5.2 In the conditions mentioned in 6.5.1, there shall be no occultation in the field of vision and shall 
satisfy the following requirements:  
a) Horizontally - Two segments of dihedral angles symmetrical in relation to the median longitudinal 
vertical plane of t he headform and situated between the reference and the basic planes. Each of these 
dihedral angles is defined by longitudinal vertical plane forming an angle of not less than 105◦ with the 
median longitudinal vertical plane and whose edge is the straight l ine L K (see fig. 2A, 2B, 3A and 3C).  
b) Upwards – A dihedral angle defined by the reference plane of the headform and a plane forming an 
angle of not less than 7◦ with the reference plane and whose edge is the straight line L 1, L2: The points L 1 
and L 2 representing the eyes (see fig, 3A and 3B).  
c) Downwards – A dihedral angle defined by the basic plane of the headform and a plane forming an 
angel of not less than 450 with the basic plane and whose edge is the straight line k 1, k 2(see fig. 3A and 
3B). 
ALL DIMENSIONS IN MILLIMETERS.  
 
Fig. 2 HEAD FORM  
 
  Headforms  sizes  x y AC HD 
A 
C 
E 
G 
J 
K 
M 
O 500 
520 
540 
560 
570 
580 
600 
620 24 
25 
26 
27 
27.5  
28 
29 
30 89.5  
93 
96 
99 
102.5  
104 
107 
110 80 
82 
84 
86 
87 
88 
90 
92 88 
90 
92 
94 
95 
96 
98 
100  
 
 
 
 
 
 
 
 
 
6.6 Visor  
The requirements in regard to visor, if provided shall  be as specified in NS2**…  
7 WORKMANSHIP AND FINISH  
7.1 All edges shall be smooth and rounded. Any external or internal projection permitted under 6.2.4, 
6.2.5 and 6.2.6 shall be soft, smooth and adequa tely faired to other surface.  
8 MASS  
8.1 The helmets with less mass are preferred and may be available with the increasing availability or 
more advanced composites  helmet (without peak, visor and detachable lower face cover, if provided) 
shall not exceed 1 500 g.  
9 PERFORMANCE REQUIRMENTS  
9.1 Impact Absorption T est 
9.1.1  Types  of conditioning  
Prior to an y type of further conditioning for mechanical tests, each helmet shall be  subjected to solvent 
conditioning:  
 
a) Solvent conditioning — Take a cotton doth approximately 150 mm square and a quantity 
approximately 25 ml of a solvent consisting of test liquid with (70 percent octane and 30 percent 
toluene). Using the cloth soaked in the solvent,  apply the solvent to  all those regions of the outside 
surface of the helmet shell within 50 mm of the chin strap fixings and keep these regio ns wet within the 
solvent for 7. 5 ± 2.5 seconds. Repeat the procedure on the remainder of the external surface including 
any chin guard * keeping these regions wet for 12.5 ± 2. 5 seconds. No further conditioning or testing be 
done during the following 30 minutes*  
b) Ambient ( temperature and humidity) conditioning — The helmet shall be expo sed to a temperature 
of 25 ± 50C and a relative hu midity of 65 ±5 percent for at least 4 hours in an oven.  
c) Heat conditioning — The helmet shall be exposed to a temperature of 50 ± TC for not less than 4 
hours and not more than 6 hours in dry heat.  
d) Low -temperature conditioning — The helmet shall be  exposed to a temperature of-20 ± 20C for not 
less than 4 hours sad not more than 6 hours in a cold chamber.  
c) Ultraviolet -radiation conditioning  and moisture conditioning — The outer surface of the protective 
helmet shall be exposed to ultraviolet radia tion by a 125 watt zenonfilled quartz lamp for 48 hours at a 
range of 25 cm subsequently spaying for 4 to 6 hou rs with water at ambient temperature at the rate of 1 
litre per minute.  
The conditioned helmet shall be tested for impact absorption test by the  method described in Annex C. 
The first Impact shall be carried out within 45 seconds. All the subsequent impacts shall be completed 
within not more than 5 minutes after subjecting to the conditions specified in 9.1.1(a) to (e) above, and 
samples to be con ditioned shall be as per Table 1 .  
The conditioned helmet tested shall meet the requirements, when the resultant acceleration (RMS value 
of acceleration measured along the three directions) measured at the center of gravity of the headform 
shall be  < 150 g n (where g n = 9.81 m/sec2) for any 5 milii seconds continuous ly and at no time exceeds 
300 g n.  
 
 
 
 
 
 
 
 
 
 
 Table 1 conditioning of samples  
Caluse (9.1)  
                 Number of helmet to be conditioned                                                                                        Total  
Test  Ambient 
temperature 
and hygrometry 
conditioning  Heat 
conditioning  Low 
temperature 
conditioning  Ultraviolet 
radiation 
cond itioning and 
moisture 
conditioning   
Impact  
Absorption  1 1 1 1 4 
Resistance  to 
penetration  1    1* 
rigidity  2    2 
Retention 
system  1    1 
*To be tested under the condition which has given the worst results in impact absorption test.  
 
 
9.2 Resistance -to-penetration Test  
Helmet shall be subjected to test in accordance with the method specified in Annex D at two points 
within  the area of protection at least 5 mm distant from each other and from any earlier point of i mpact, 
after subjectin g to pro cess of conditionin g which has given the least, sa tisfactory results in impact -
abso rption test. During the test* the head of the punch shall no) come closer than 5 mm measured 
vertically to the headform.  
9.3 Rigidity Test  
The helm et shal l be test ed by the method prescribed in Annex  B and shall meet the following 
requirements :  
a) Along eac h axis, the deformation measur ed under 630 N load shall not exceed by 40 mm than that 
measured under the initial 30 N load.  
b) After resto ration of 30 N load, t he defor mation measured shall not exceed by 15 mm than that 
measured under the initial 30 N load.  
9.4 Dynamic Test of retention System   
Helmet shall be tested for thei r retention system by the method given in Annex F and it shall meet the 
following  requir ements :  
a) The dynamic displacement of the point of application of the force shall not exceed 35 mm,  b) After two minutes, the residual displace ment of the point of application of the force, as measured 
under a mass of 15 ± 0. 5 kg shall not exceed 25 mm,   
c) Damage to the retention system shall be accepted provided that it is still possible to take the helmet 
easily off the headform and that the requirements given in (a) and (b) above are  met.  
9.5 Audibility Test  
The helm et shall be tested for their  sound attenuation properties by the method given in Annex G. The 
sound transmission loss shall be not more than 10 dB oven the frequency range 250 to 2 000 Hz.  
9.6 Retention Test of Hemet   
The helmet previously conditioned at ambient temperature and humi dity, shall be placed on and 
secured to t he appropriate headform, selec ted from those listed in Fig. 2 A and 2B, in accordance with 
the requirements given in Annex C -1.3.  
A device to  guide and release a falling mass  (the total mass being 3 ± 0. 1 kg ) is h ooked on to the rear 
part of the shell in the median vertical plane of the helmet, as show n in Fig. 7.  
The falling mass of (10 kg ± O -OI kg) is then released and drops in a guided free fall from a height of 0 .50 
m ± 0 .01 m.  
After the test, the angle betw een the reference line situated on the crown of the helmet and the 
reference plane of the headform shall not exceed 30°.  
9.7 Opening Angle (visor)  Test  
The helmet , fitted with the visor being tested, shall be placed on a test headform of appropriate size , 
selected from those listed m Fig. 2A, in accordance with the provisions given in  
Annex C -1.3,  
When the visor is in the raised position, the angle between the secant MN defined  in Fig. 8 and the  
horizontal shall be at least 50, With  the point M situated  below the horizontal plane passing through 
point N.   
9.8 Flexibility of Peak  
Where provided it shall be tested by the method described in Annex H. The peak shall neither break nor 
become detached from the helmet. Its deflection shall be between 6 mm and 32 mm.  
10 SAMPLING AND CRITERIA FOR CONFORMITY  
The method of sampling and criteria for conformity shall be as per  NS5* *...  
11 INSTRUCTIONS  
Each helmet shall be supplied with a printed card fixed with a tag having the following information:  
a) For adeq uate protection, the helmet shall fit closely and the chin strap shall be under tension at all 
times of vehicular use;  
b) The helmet is made to absorb some of the energy of a blow by partial destruction of its component 
parts and even though damage may no t be readily apparent, any helmet subjected to severe impact 
should be discarded; and  c) To maintain the full  efficie ncy of this helmet, there shall be no alteration to the structure of the 
helmet or its component parts.  
12 MARKING  
12.1 Each  helmet shall be clearly and indelibly marked with the following information on the inside of 
the helmet:  
a) Manu facturer's name or trade -mark,  
b) Size,  
c) Year of manufacture, and  
d) Mass of helmet to the nearest 20 g.  
 
12.1.1  Certificate  Marking  
The helmet may also be marked with the Standard Mark. Detail  are available with the Bureau of Nepal  
Standards.  
ANNEX A  
( Clause 2 )  
 
LIST OF REFERRED STANDARDS  
NS1**         Method of testing corrosi on resistance of electroplated and anodized aluminium co ating by    
                     neutral salt spray test  
NS2**          Specification for visor for scooter helmets  
NS3**         specification for wooden headforms for testing of helmets  
NS4**        specification for electric horns for automobiles  
NS5**       Methods for sampling of helmets  
NS6**       specification for sound level meters  
 
ANNEX B  
(Clause 6.5.1)  
POSITIONING OF THE HELMET OF THE HEADFORM  
B-1 The helmet is placed on a headform of appropriate size. A load of 50 N is applied on the crown of 
the helmet  in order to adjust the helmet on the headform. It shall be ascertained that the vertical 
median plane of the helmet coincides with the median vertical plane of the headform.  B-2 The front edge of the helmet is placed against a guage to check the  minimum angle for the upward 
field of vision. The following points are then checked.  
B-2.1 The line AC and the ACDEF zone are covered by the shell (see Fig. 2) and the requirements for the 
minimum downward angle and th e horizontal field of vision are  satisfied.  
B-2.2 Requirements mentioned in 6.2.2 relating to the rear projection shall be met with.  
B-3 If the  conditions mentioned in B -2 are  not met, the helmet is moved slightly from front to rear to 
seek a position where all the requirements are met. Once such a position is determined, a horizontal line 
is drawn on the shell at the level of the AA plane. This horizontal line shall deter - mine the reference 
plane for the positioning of the helmet during the tests.  
ANNEX C  
( Clause 9.1 )  
 
IMPACT ABSORPTION TEST  
 
C-1 DESCRIPTION OF TEST  
C-1.1 Principle  
Impact absorption capacity is determ ined by recording against time the acceleration imparte d to a 
headform fitted with the helmet , when dropped in guided free fall at e specified impact velocity upon a 
fixed steel anvil.  
 
C-1.2 Marking of points of impact  
Before conditioning, the points of impact shall be marked as indicated in Fig. 4.  
C-1.3 positioning of the Helmet after conditioning  
The helmet shall be positioned in accordance with the requirements of Annex B on a headform of 
appropriate size selected from among those listed in C -2.1.5. The helmet shall then be tipped towards 
the rear so th at the front edge of the helmet in the median plane is displaced by 25 mm; the retent ion 
system shall then be adjus ted under the chin of the headform; if the system includes an adjustable chin -
strap, the strap is tightened as much as possible.  
 
C-1.4 The test headform shall be so positioned that the designate d point on the helmet is verti cally 
above the centre of the anvil. The plane tangential to the point of impact shall be horizontal.  
C-2 APPARATUS (see Fig. 5)  
C-2.1 The test apparatus shall comprise o f the following  
a) A base  
b) An anvil rigidily fixed to a base,  c) A free fall guidance system,  
d) A mobile system supporting the helmeted headform,  
e) A metal headform fitted with a tridirectional accelerometer and  a measuring assembly, and  
f) A system by which the point  of impact may be brought into correspondence with the centre of the 
anvil.  
C-2.1.1 Base  
The base shall be made of steel or concrete or a combination of th ese materials and have masa of at 
least 500 kg . It shall be so constructed that there is no sign ificant deformation of surface under the test 
load.  
No part of the base or anvil shall have a resonance frequency  liable to affect the measure nts.  
C-2.1.2 Anvils  
C-2.1.2.1  The flat ste el anvil shall have a circular impact face of 130 ± 3 mm in diameter  
C-2.1.2.2  The h emispherical steel anvil shall have an impact face of 50 ± 2 mm in radius.  
C-2.1.3  Mobile System and Guides  
The mobile system  supporting the headform shall be such that it’s  characteristics do not af fect the 
meas urement of acceleration at the centre of gravity of the headform. It shall also be such that a ny 
point in the area ACDEF can be positioned vertically above the centr e of the anvil.  
C-2.1.4  Accelerometer and Measuring Assembly  
The accelerometer shall be c apable of withstandin g a m aximum acceleration of 2 000 g without damage. 
Its mass shall be 50 g. The measuring system including the drop assembly shall have a frequency 
response in accordance with the following requirements:  
a) Frequency  response shall be  Hat between 0.1 HZ to 1 000 HZ  within ±5 dB (that  is for a co nstant input 
acceleration with the frequency band, the output shall be constant within ±5 dB);  
b) Sampl ing frequency shall be minimum 10 kHZ ;  
c) Minim um resolution of the equipment shall be 1  part in 236 parts or greater; and  
d) Overall erro r within frequency range shall not ex ceed 2 percent.  
C-2.1.5 Headfroms  
The shape of the te st headform to be used for the impact -absorption shall comply with the 
requirements of  NS3**… for dimensions below and above the reference plane. The gene ral 
characteristi cs of the test headforms to be used shall be as given in the Table 2.  
 
 
 
  
Table 2 General characteristics of  Test  Headform  
(Clause c -2.1.5)  
 
Symbol                                                              size   (mm)                                                mass (kg)  
A                                                                           500                                                          3.1±0.10                     
E                                                                           540                                                           4.1±0.12    
J                                                                           570                                                             4.7±0.14  
M                                                                         600                                                             5.6±0.16  
O                                                                          620                                                           6.1±0.18  
 
 
Note – headform of sizes not listed in Table 2 shall be tested with the next smallest headform size given 
in Fig.2.  
C-2.1.6  The cen tre of gravity of the headform shall be near the p oint G on the central vertical axis at 
"1”mm below the reference plan,  as defined in  NS3**……..,  RMS values of accele ration shall be 
measured along the three direc tions.  
The headform sha ll contain, near its centre of gravity, a housing for a tri-directional accelero meter, such 
that the inertial centre of the accelerometer sha ll be at the centre of gravity of the headform.  
C-3 IMPACT VELOCITY  
The drop heig ht shall be such that the unit the constituted by  the headform and helmet falls on test 
anvil  at a velocity which immediately before  impact shall be equal to 7 -0.35+0.0 m/s for anvils as given in C -
2.1.2.1 and 6 -0.15+0.0m/s for anvils specified in C -2.1.2.2.  
C-3.1 The veloci ty of the moving mass shall be measured betwee n I cm and 6 cm before impac t, to an 
accuracy of 1 per cent. The acceleration against  time* a t the centre of gravity of the headform shall be 
measured as specified in C -2.1.4   
C-4 METHOD  
C-4.1 Selection of points of impact  
Each  test shall be carried out first with the flat anvil and t hen with the hemisp herical anvil on the s ame 
helmet at two neighbo ring but sepa rate points. The distance between the two points shall be 15±5 mm 
except for the two points X and X t for which the distance shall be 60 ±5 mm   
C-4.2 Six points of impact shall be defined for each type of helmet:  
a) In the fro ntal area, B and B 1 situated in  the vertical plane of symmetry of the helmet and above point 
B;  
b) In the late ral area, X and Xu at an angle of 45* rearwards and upwards; and  
c) P and Pi, above the plane parallel to the base plane passing through point A,  
C-4.3 The test  sequence shall conform to the Table 3.   
Table 3 Sequence of testing impact -absorption test  
Clause C -4.3 
 
Conditioning                                                                  anvils                                         points of im pact 
Ambient                                                  Flat then hemispherical                                      B and B 1   
                                                                                                                                                  X and X 1 
Under any condition                             Flat then hemispherical                                      P and P 1  
as mentioned in 9.1.1 (a)  
to (e)  
 
Heat                                                    Flat then hemispherical                                          B and B 1 
                                                                                                                                                 X and X 1 
Low temperature                             Flat then hemispherical                                           B and B 1   
                                                                                                                                                  X and X 1                                                                              
Ultra -violet radiation                      Flat then hemispherical                                             B and B 1   
                                                                                                                                                  X and X 1 
And moisture  
 
ANNEX D  
(Clause 9.2)  
RESISTANCE TO PENETRATION TEST  
D-1 PROCEDURE  
D-1.1 The protective helmet shall be placed, with an initial load of 10 N,  on a headform oriented to such 
a wa y that the plane tangential  to the shell at the point se lected for the test is substan tially horizontal. A 
metal punch with a conical head rounded at the t op shall be placed vertically to touch t he shell at the 
point selected and h eld in position by a ring. A metal  drop hammer shall fall on the top of the punch, 
and the depth to which the point penetrates into the shell shall be measured by means of an inert ia- 
free device, such a s a photoelectric device, indi cating the minimum vertical distance reached, in this test 
between the head of the punch and the he adform.  
D-1.2 The testing device mentioned in D -1.1 shall have the following characteristics:  
 
         Mass of punch                                                                   0.3±0.01 kg  
 
Angle of cone forming                                                      60±1◦ 
                                               punch head  
 
Radius of rounded top                                                       0.5 mm                                               of punch head  
 
Mass of drop hammer                                                      3±0.025 kg  
Height of fall measured                                                     1±0.005 m  
                                      Between  top face of  
                                      Punch  and lower face  
                                      Of drop hammer  
 
             Hardness of tip                                                            between  45 and 50◦  
                                                                                                                               Rockwell, scale C  
                                Minimum cone height                                                                   40 mm  
 
  
ANNEXE  E 
(Clause  9.3) 
RIGIDITY TEST  
E-1 PEOCEDUR E  
E-1.1 The helmet, after undergoing ambient - temperature and h umidity conditioning, shall be placed 
betw een two parallel plates by means of which a known load can be applied along the longitudinal axis 
(line LL in the figure below ). An initial load of 30N shall be applied, and   after two mi nutes the distance 
between the plates shall be me asured. The load shall then be increased by 100 N every two minutes to a 
maximum of 630 N.  After two minutes of application of the 630 N load, the distance between the plates 
shall be measured.  
E-1.2 The load ap plied to the plates shall then be reduced to 30 N aga in and kept at that value  
 
                                                            
for five minutes; t he distance between the plates shall then be measured.  
E-1.3 The helmet used for the test along the longitudinal axis shall be a new helmet and another new 
helmet shall be used for the test along the transverse axis.  
ANNEX F  
(Clause  9.4) 
 
DYNAMIC TEST OF THE RETENTION SYSTEM  
 
F-1 PROCEDURE  
F-1.1 The helmet shall be positioned as prescribed in C -1.3.  
F-1.2 In this positi on the helmet shall be held by the shell (see  Fig. 6) at penetration p oint of the vertical 
axis passing through the centre of gravity of the headform. The headform is equip ped with a load -
bearing device aligned with the vertical axis  passing through the centre of gravity of the  headform and 
with a device to measure the vert ical displacement of the point of application of the force.  
F-1.3 A guide a nd arrest device for a falling mass shall then be atta ched below the headform.  
The mass of the headform so equipped in this way shall  be 15 ± 0. 5 kg; this produces t he preloading on  
the retention system for determining  the po sition from which the vertical displacement of t he point of 
application of the force shall be measured.  
F-1.4 The fall ing mass of 10 ± 0.1 kg shall then be released 9Xid shall drop in a gu ided free fall from a 
height of 750 ± 5 mm.  
  
 
 
 
 
 
ANNEX G  
(Clause 9.5)  
AUDIBILITY  TEST  
 
G.1 APPARATUS  
G-1.1 Measuring Apparatus  
Measuring apparat us shall consist of a headform conformin g to NS3**….  and sound level meter in 
accordance with  NS6**……..  The microphone of sou nd level meter shall be fitted at a place 
corresponding to the rig ht or left human ear’ s location.  
NOTE — For this test weighting network Curve A shal l be used.  
G.1.2 Sound Source  
The sound surface shall be a horn conforming to Type 2A of NS4**…. (which has sound pressure level 
range of 90 to 115 dB(A). Th e sound source sha ll be located so that sound is incident from back of the 
headform.  
G-2 PROCEDURE  
G-2.1 This test shall be carri ed out under the prevailing atmosp heric conditions and the background 
noise level shall be such that the reading indicated on the sound level meter by the noise is at least 10 
dB o f below that of the horn sound level. This test s hall be carried out in an o pen space in which  there is 
no obstacle within a radius of 12 m and no acoustical focusing  affects or nearby parallel walls. The horn 
shall be mounted 1.2 m above the ground and shall be fixed in a rigi d manner on a base whose mass 
shall b e at least 10 tim es that of the horn and not less than 1 5 kg and shall be adjustable sidew ays and 
up and down. The sound waves are emitted from the  horn by using suitable 12 V dc  power supply and 
are directed towards the rear of the headform at the distance of 2 m. The two readings are take n with 
and without helmet. The difference shall be recorded to the nearest dB.  
 
 
ANNEX H  
(Clause 9.6 ) 
TEST FOR FLEXIBILITY OF PEAK  
H-1 PROCEDU RE  
H-1.1 The helmet  shall be left on the headform used for the  test described in Annex D and loaded  with a 
load  of 120 N to hold it firmly in place. A mass carrier having a mass of U4 g shall be suspen ded from the 
front edge of the peak at its  centr e by m eans of small hook and a light strong thr ead passing over a 
pulley. The position of the pu lley shall be adjusted so that the thread is perpendicular to the peak at its  
point of attac hment. A mass of I kg shall be placed gently  on the carrier and left for 2  minut es, after 
which time the resulting movement sh all be measured by means of an index attached to the thread 
below the pulley and moving over a fixed vertical scale.