EN 379:2003

SLOVENSKI STANDARD
01-december-2003
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SIST EN 379:1996
SIST EN 379:1996/A1:1999
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Personal eye-protection - Automatic welding filters
Persönlicher Augenschutz - Automatische Schweißerschutzfilter
Protection individuelle de l'?il - Filtres de soudage automatique
Ta slovenski standard je istoveten z: EN 379:2003
ICS:
13.340.20 Varovalna oprema za glavo Head protective equipment
25.160.01 Varjenje, trdo in mehko Welding, brazing and
spajkanje na splošno soldering in general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN 379
NORME EUROPÉENNE
EUROPÄISCHE NORM
September 2003
ICS 13.340.20 Supersedes EN 379:1994
English version
Personal eye-protection - Automatic welding filters
Protection individuelle de l'oeil - Filtres de soudage Persönlicher Augenschutz - Automatische
automatique Schweißerschutzfilter
This European Standard was approved by CEN on 1 August 2003.
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 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 Management Centre has the same status as the official
versions.
CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece,
Hungary, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Slovakia, Spain, Sweden, Switzerland and United
Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2003 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 379:2003 E
worldwide for CEN national Members.

Contents Page
Foreword. 3
1 Scope . 4
2 Normative references . 4
3 Terms and definitions. 4
4 Requirements . 6
4.1 General requirements. 6
4.2 Particular requirements. 6
4.3 Additional requirements. 6
4.3.1 Power off. 6
4.3.2 Transmittance. 6
4.3.3 Variations in luminous transmittance. 7
4.3.4 Switching time. 7
4.3.5 Manual control of dark scale number . 8
4.3.6 Diffusion of light . 8
4.3.7 Angle dependence of luminous transmittance (Optional requirement). 9
4.4 Spectral sensitivity of welding filters with automatic scale number setting. 9
5 Test methods. 9
5.1 Power off test . 9
5.2 Measurement of switching time . 9
5.2.1 Test equipment . 9
5.2.2 Performance of test equipment. 10
5.2.3 Measurement. 10
5.2.4 Calculation. 10
5.3 Scale number setting of welding filters with automatic scale number setting . 10
5.3.1 Test equipment . 10
5.3.2 Measurement of the scale number setting. 10
5.4 Spectral sensitivity of welding filters with automatic scale number setting. 11
5.4.1 General. 11
5.4.2 Method using monochromatic radiation . 11
5.4.3 Method using cut-off filters. 11
5.5 Angle dependence of luminous transmittance. 11
5.6 Test schedule for type examination. 12
6 Marking . 13
6.1 General. 13
6.2 Automatic welding filters and automatic welding filters with manual scale number setting . 13
6.3 Welding filter with automatic scale number setting. 14
7 Information to be supplied by the manufacturer. 14
Annex A (informative) Guidance on selection and use . 15
A.1 General. 15
A.1.1 Scale numbers to be used for gas welding and braze welding . 15
A.1.2 Scale numbers to be used for oxygen cutting. 16
A.1.3 Scale numbers to be used for plasma jet cutting.16
A.1.4 Scale numbers to be used for electric arc welding or air-arc gouging. 16
A.1.5 Scale numbers of filters to be used by welders’ assistants. 16
A.2 Remarks. 18
Annex B (informative) Uncertainty of measurement and results interpretation. 19
B.1 Test report and uncertainty of measurement . 19
Annex ZA (informative)  Clauses of this European Standard addressing essential requirements or
other provisions of EU Directives. . 21
Bibliography . 22
Foreword
This document (EN 379:2003) has been prepared by Technical Committee CEN/TC 85 “Eye-protective equipment”,
the secretariat of which is held by AFNOR.
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 March 2004, and conflicting national standards shall be withdrawn at the latest by
March 2004.
This document has been prepared under a mandate given to CEN by the European Commission and the European
Free Trade Association, and supports essential requirements of EU Directive.
For relationship with EU Directive, see informative annex ZA, which is an integral part of this document.
Annexes A and B are informative.
This document supersedes EN 379:1994.
In the revision of this European standard, and that of EN 169, which was performed concurrently, it was decided to
remove from EN 379 welding filters with dual scale numbers and include them within EN 169.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal,
Slovakia, Spain, Sweden, Switzerland and the United Kingdom.
1 Scope
This European standard specifies requirements for automatic welding filters which switch their luminous
transmittance to a lower predetermined value when a welding arc is ignited (referred to as welding filters with
switchable scale numbers). It also specifies requirements for automatic welding filters which switch their luminous
transmittance to a lower value, where the lower value of luminous transmittance is set automatically in dependence
on the illuminance generated by the welding arc (referred to as welding filters with automatic scale number setting).
The requirements of this standard apply if such a filter is to be used for continuous viewing of the welding process,
(including gas welding and cutting), and if it is to be used only during the period when the arc is being ignited.
These filters are used in welders' eye protectors or are fixed to equipment.
If they are to be used in welders’ eye protectors, other applicable requirements for these types of filters are given in
EN 166. The requirements for the frames/mountings to which they are intended to be fitted are given in EN 175.
Guidance on the selection and use of these filters is given in annex A.
The specifications for welding filters without switchable luminous transmittance are given in EN 169.
2 Normative references
This European Standard incorporates by dated or undated reference, provisions from other publications. These
normative references are cited at the appropriate places in the text and the publications are listed hereafter. For
dated references, subsequent amendments to or revisions of any of these publications apply to this European
Standard only when incorporated in it by amendment or revision. For undated references the latest edition of the
publication referred to applies (including amendments).
EN 165:1995, Personal eye-protection – Vocabulary.
EN 166:2001, Personal eye-protection - Specifications.
EN 167:2001, Personal eye-protection - Optical test methods.
EN 168:2001, Personal eye-protection - Non-optical test methods.
1)
EN 169:2002 , Personal eye-protection - Filters for welding and related techniques - Transmittance requirements
and recommended use.
ISO 9211-2:1994, Optics and optical instruments -- Optical coatings -- Part 2: Optical properties
ISO/CIE 10526:1999, CIE standard illuminants for colorimetry.
3 Terms and definitions
For the purposes of this European Standard, the terms and definitions given in EN 165:1995 and the following
apply.
3.1
automatic welding filter
a protective filter which automatically switches its scale number from a lower value (light state scale number) to a
higher value (dark state scale number) when the welding arc is ignited

1) To be published
3.1.1
automatic welding filter with manual scale number setting
a protective filter which automatically switches its scale number from a lower value (light state scale number) to a
higher value (dark state scale number) selected by the user when the welding arc is ignited.
3.1.2
automatic welding filter with automatic scale number setting
A welding filter with switchable scale number, in which the dark state scale number depends upon the illuminance
generated by the welding arc.
3.2
light state scale number
the scale number corresponding to the maximum value of luminous transmittance t (see Figure 1)
5     10 11 12 13 14
t---------------------------t -------------------------------t1 d 2
Light state Lightest dark state Intermediate dark state Darkest state
scale number scale number scale number
Figure 1 - Example showing the meaning of the terms in the case of an automatic welding filter with a light
state scale number of 5 and dark state scale numbers between 10 and 14
3.3
dark state scale number
the scale number corresponding to the value of the luminous transmittance t reached after the ignition of the
d
welding arc by an automatic welding filter (see Figure 1)
3.4
darkest state scale number
the highest scale number corresponding to the minimum value of luminous transmittance t of an automatic
welding filter claimed by the manufacturer (see Figure 1)
3.5
switching time
the switching time t of an automatic welding filter is defined by the following integral:
s
t=t (t(t)=3t)
1 2
ttt t
= ( )d
s
∫
t=0
t
where
t = 0 is the time at which the arc ignites;
t (t) is luminous transmittance at a time t after the ignition of the welding arc;
t = t (t (t)=3·t) is the time at which the luminous transmittance falls to 3 times the luminous transmittance in
the darkest state.
NOTE In the case of short term exposure to light, the glare is approximately proportional to the product of the illuminance
at the eye and time. The time relationship of the darkening process can be very different depending on the construction of the
welding filter with switchable scale number. It is therefore appropriate to define the switching time as an integral of the luminous
transmittance over time and not merely by the initial and final luminous transmittances.
3.6
cut-off filter
a filter with a range of low spectral transmittance (cut-off band) followed by a range with high spectral transmittance
(pass-band) or vice versa, with properties described according to ISO 9211-2:1994.
4 Requirements
4.1 General requirements
Automatic welding filters shall comply with requirements given in Table 1. These requirements shall be met for the
highest possible scale number as may be set under either automatic setting (including manual offset) or manual
setting.
Table 1 - General requirements
Property Requirement
Spherical, astigmatic and prismatic refractive EN 166:2001, 7.1.2.1.2
powers
Luminous transmittance EN 169:2002, Table 1
Variations in luminous transmittance 4.3.3
Spectral transmittance EN 169:2002, Table 1
Diffusion of light 4.3.6
Quality of material and surface EN 166:2001, 7.1.3
Robustness of construction EN 166:2001, 7.1.4
Resistance to ultraviolet radiation EN 166:2001, 7.1.5.2, but replacing 7.1.5.2 b) by 4.3.6 of this
European standard
Resistance to ignition EN 166:2001, 7.1.7
4.2 Particular requirements
Where a manufacturer wishes to claim compliance with particular requirements, these requirements shall be as
specified in EN 166:2001, 7.2.2 to 7.2.8 and 7.3.
4.3 Additional requirements
4.3.1 Power off
When tested according to 5.1, automatic welding filters shall be no more than nine scale numbers lighter than the
darkest state scale number.
4.3.2 Transmittance
4.3.2.1 The requirements of 4.3.2.2, 4.3.2.3 and 4.3.2.4 shall be satisfied when the transmittances are
measured as described in EN 167:2001, 6, using standard illuminant A.
4.3.2.2 The minimum luminous transmittance in the light state shall be 0,16% when measured at both
o o
(-5 ± 2) C and (55 ± 2) C.
4.3.2.3 The luminous transmittance requirements given in EN 169:2002, Table 1, shall apply to both light and
o o
dark states (t tand t ). The measurements shall be taken at both (- 5 ± 2) C and (55 ± 2) C.
1, d 2
4.3.2.4 The spectral transmittance in the ultraviolet and the mean transmittance in the infrared, as given in EN
169:2002, Table 1, and the additional requirements (a) to (d) of EN 169:2002, 5.2, required for the darkest state
scale number, shall also apply to all other states. The measurements shall be taken at a temperature of
o
(23 ± 5) C.
4.3.2.5 In the case of welding filters with automatic scale number setting, this setting of the dark state scale
number shall meet the following requirements:
a) The dark state scale number N(E ) shall depend on the illuminance E as follows:
v v
N(E ) = 2,93 + 2,25log(E / lx)
v v
Some values calculated from this formula are given as examples in Table 2, for scale numbers between
8 and 14:
Table 2 - Dark state scale number
Dark state scale number
Scale number N
8 9 10 11 12 13 14
Illuminance / lx 180 500 1 400 3 900 10 700 30 000 83 000
b) The scale number set in dependence on the illuminance at the filter front shall not deviate by more than –1
scale number from the scale number given by the formula in (a).
c) The range of the luminous transmittance of the welding filter shall be limited by design not to exceed the
manufacturer’s claimed darkest state scale number.
d) A manual offset may be provided, which allows the automatically set scale number to be changed by –1 scale
number. This shall be tested at both minimum and maximum settings.
e) When tested using double the illuminance given by the formula in (a) for the darkest state scale number, the
luminous transmittance shall correspond to the darkest state scale number claimed by the manufacturer.
4.3.3 Variations in luminous transmittance
o
When measured in accordance with clauses 7.1 and 7.2 of EN 167:2001 at a temperature of (23 ± 5) C the values
of P , P and P of welding filters with switchable scale number shall not exceed the values in Table 3 for the
1 2 3
assigned class. The requirement shall apply to both light and dark states (t tand t ).
1, d
Table 3 - Classification of oculars according to the maximum value of P , P or P as specified in 4.3.3
1 2 3
Luminous transmittance Maximum value of P or P Maximum value of P
1 2 3
% % %
max. min. Class 1 Class 2 Class 3 Class 1 Class 2 Class 3
100 17,9 5 10 15 20 20 20
17,9 0,44 10 15202020 20
0,44 0,023 15 20 30 20 20 30
0,023 0,0012 20 30 40 20 30 40
0,0012 0,000023 30 40 60 30 40 60
4.3.4 Switching time
4.3.4.1 The switching times shall satisfy either 4.3.4.2 or 4.3.4.3 for the darkest state.
o
4.3.4.2 The switching time shall be measured as described in clause 5.2 at temperatures of (-5 ± 2) C and
o
(55 ± 2) C. The switching time given in Table 4 shall not be exceeded at either of these temperatures.
o
4.3.4.3 The switching time shall be measured as described in clause 5.2 at temperatures of (10 ± 2) C and
o
(55 ± 2) C. The switching time given in Table 4 shall not be exceeded at either of these temperatures.
Table 4 - Maximum switching times
Light state scale number
1,7 2 2,5 3 4 5 6
Dark state scale
number
Switching time
ms
7 300 400 500 700 1000 No requirement No requirement
8 100 150 200 300 500 1000 No requirement
9 40 50 70 100 200 400 700
10 20 20 30 40 70 100 300
11 6 7 10 15 30 50 100
12 2 3 4 5 10 20 40
13 0,8 1 1,5 2 4 7 10
14 0,3 0,4 0,5 0,7 1 3 5
15 0,10 0,15 0,2 0,3 0,5 1 2
16 0,04 0,05 0,07 0,1 0,2 0,4 0,7
NOTE The values given in Table 4 are based on a 0,5 s duration of glare when the welding arc is ignited. (see: E. Buhr, E.
Sutter: Dynamic Filters for Protective Devices, in: G. J. Müller, D. H. Sliney (Hrsg.): Dosimetry of Laser Radiation in Medicine
and Biology, SPIE IS 5, 175-195, Washington 1989)
4.3.5 Manual control of dark scale number
When a manual control of the dark scale number is provided, the means of control shall meet the following
requirements:
a) There shall be a digital indication of the scale number for each position of the manual control;
4 3
b) With an illuminance of (10 ± 10 ) lx on the filter, the scale number in the dark states (tand t) shall not
d 2
deviate by more than ±1 from the set scale number;
c) If the range of control is more than five scale numbers, it shall be divided into two sub-ranges with separate
manual controls. Each manual control shall control a sub-range of no more than five scale numbers. In the case of
automatic welding filters with manual control according to 4.3.2.5 e), the total scale number range shall not exceed
seven scale numbers, (including the tolerance of 4.3.5 (b) and the provision of 4.3.2.5 e)).
4.3.6 Diffusion of light
The diffusion of light shall be measured in accordance with one of the reference methods described in
EN 167:2001, 4.
The maximum value of the reduced luminance factor in the light or dark state shall determine the diffusion of light
class of the welding filter as shown in Table 5.
Table 5 - Assignment of diffusion of light class
Diffusion of light Maximum value of reduced
luminance factor
class
(cd/m )/lx
11,0
22,0
33,0
4.3.7 Angle dependence of luminous transmittance (Optional requirement)
The luminous transmittance is measured at normal to the filter and at angles of incidence up to ±1
...