BS EN 169:2002 pdf download – Personal eye-protection — Filters for welding and related techniques — Transmittance requirements and recommended use
1 Scope
This European Standard specifies the scale numbers and transmittance requirements for filters intended to protect operators performing work involving welding, braze-welding, air-arc gouging and plasma jet cutting. It also includes requirements for welding filters with dual scale numbers. The other applicable requirements for these types of filters are given in EN 1 66. The requirements for the frames/mountings to which they are intended to be fitted are given in EN 1 75. Guidance on the selection and use of these filters are given in Annex A. The specifications for welding filters with switchable luminous transmittance are given in EN 379. 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 1 65, Personal eye-protection – Vocabulary.
EN 1 66, Personal eye-protection – Specifications.
EN 1 67:2001 , Personal eye-protection – Optical test methods. ISO/CIE 1 0526:1 999, CIE standard illuminants for colorimetry.
ISO/CIE 1 0527:1 991 , CIE standard colorimetric observers.
3 Terms and definitions For the purposes of this European Standard, the terms and definitions given in EN 1 65 and the following apply.
3.1 welding filter with dual scale number a protective filter with two different scale numbers (light and dark zones) which are divided into a maximum of three areas of the filter. The light zone is used for brief viewing when setting the electrode to the weld and igniting it. The dark zone is used for viewing the welding process
4 Designation and identification
The complete table of numbering of filters is given in EN 1 66. The marking of oculars and frame is described in EN 1 66. The scale number of these filters comprises only the shade number corresponding to the filter, from 1 ,2 to 1 6 (see Table 1 ).
5 Requirements
5.1 General
The requirements of EN 1 66 apply to welding filters. Only those requirements that are different from or supplement the EN 1 66 specifications are given in this European Standard.
5.2 Transmittance requirements
The definitions of transmittances are given in EN 1 65.
The determination of luminous transmittance is described in EN 1 67.
The transmittance requirements for filters used in welding and related techniques are given in Table 1 .
NOTE 1 Luminous transmittance values are based on the spectral distribution of illuminant A and on the CIE (1 931 ) standard observer (2°) (see ISO/CIE 10526:1 999 and ISO/CIE 10527:1 991 ). NOTE 2 The IR transmittance values are determined by integration of the spectral data.
5.3 Oculars with enhanced colour recognition (optional) Between 500 nm and 650 nm, the spectral transmittance shall be not less than 0,2 v . The relative visual attenuation quotient Q, for signal lights red, yellow, green and blue shall be not less than 0,8.
5.4 Oculars with enhanced reflectance in the infrared (optional) Oculars which are claimed to have enhanced reflectance in the infrared shall have a mean spectral reflectance greater than 60 % within the wavelength range 780 nm to 2 000 nm when measured in accordance with EN 1 67:2001 , clause 8.
5.5 Additional requirements for welding filters with dual scale number
5.5.1 Difference in scale number The difference in scale number between the light and dark zones shall be no more than five.
5.5.2 Transmittance The requirements of and shall be satisfied when the transmittances are measured in accordance with EN 1 67. The minimum luminous transmittance in the light zone shall be 0,1 6 %. The spectral transmittance in the ultraviolet and the mean transmittance in the infrared given in Table 1 and the additional requirements a) to d) in 5.2 required for the dark zone shall also apply to the light zone.
5.5.3 Dimensions The dark zone shall be at least 25 mm vertical depth across the horizontal length. Any region separating the light and dark zones shall not exceed 2 mm vertical depth across the horizontal length. This region shall provide at least the same protection against radiation as the dark zone.