BS EN 169-2002 pdf download.Personal eye-protection — Filters for welding and related techniques — Transmittance requirements and recommended use.
This BS EN 169 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 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 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 165, Personal eye-protection — Vocabulary.
EN 166, Personal eye-protection – Specifications.
EN 167:2001, Personal eye-protection — Optical test methods.
ISO/CIE 10526:1999. CIE standard illuminants for colori’netry.
ISO/CIE 10527:1991, CIE standard colorimetric observers.
3 Terms and definitions
For the purposes of this European Standard, the terms and definitions given in EN 165 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
NOTE 1 Luminous transmittance values are based on the spectral distribution of illuminant A and on the CIE (1931) standard observer (2) (see ISOICIE 10526:1999 and ISO/CIE 10527:1991).
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 z.
The relative visual attenuation quotient 0, 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 167:2001, 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
5.5.2.1 The requirements of 5.5.2.2 and 5.5.2.3 shall be satisfied when the transmittances are measured in accordance with EN 167.
5.5.2.2 The minimum luminous transmittance in the light zone shall be 0,16%.
5.5.2.3 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.
A.1 General
For the personal protection of the operator the filter must be mounted in a suitable eye protector. Eye protector types are described in EN 175.
Many factors are involved in selecting the scale number of a protective filter which is suitable for welding or related techniques.
For gas welding and related techniques. such as braze-welding, this European standard refers to the flow rate through the burners:
For arc welding, air-arc gouging, and plasma jet cutting, the current is an essential factor in making an accurate choice possible.
In addition, for arc welding, the type of arc and the type of parent metal are also to be taken into consideration. Other parameters have a significant influence, but it is difficult to evaluate their effect. These are, in particular:
— the position of the operator in relation to the flame or the arc. For examp’e. depending on whether the operator leans over his work or adopts an arm’s length position, a variation of at least one scale number can be necessary;
local lighting:
— the human factor.
For these various reasons. this European Standard only gives those scale numbers which confirmed practical experience has shown to be valid in normal circumstances for the personal protection of operators with normal sight, carrying out work of a specified type.
The scale number of the filter to be used can be read from the tables, at the intersection of the column, corresponding to the gas flow rate or the current, and the line, specifying the work to be carried out.
The Tables A.1 to A.3 are valid for average working conditions. in which the distance from the welder’s eye to the pool of molten metal is approximately 50cm and the average illuminance is approximately 100 lx.
A.1.1 Scale numbers to be used for gas welding and braze welding The scale numbers to be used for gas welding and braze welding are given in Table A.1.BS EN 169-2002 pdf download.