BS EN 169:2002 pdf download

BS EN 169:2002 pdf download.Personal eye-protection一 Filters for welding and  related techniques – Transmittance requirements and recommended use.
A.1 General
For the personal protecion of the operator me 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 titter whidi 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 consideratn. Other parameters have a significant influence, but Ills difficult to evaluate their effect. These are, in particular;
— the position of the operator in relation to the flame or the arc. For example, depending on whether the operator leans over his work or adopts an arm’s length position. a vanaflon 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.
Al .5 Scale numbers of filters to be used by welders assistants
It is necessary that welders’ assistants and other persons in the region of welding operations be protected Filters of scale number 1,2 to 4 should be used for this purpose. However, if the levels of risks requwe it, filters of higher scale numbers should be used. Especialy when the welder’s assistant would be at the same distance from the arc as the welder, both persons should use filters with me same scale numbers,
&1.6 Filters with enhanced colour recognition
Fo welding processes In which colour recognition is important, the use of welding filters with enhanced colour recognition is recommended.
&1.7 Filters with enhanced reflectance In the Infrared
For welding processes. which generate considerable heat, the use of welding ttecs with enhanced reflectance in the infrared is recommended in order 10 increase the comfort of the wearer.
A.2 Remarks
A.2.1 For a scale number corresponding to the work conditions specified in Tables Al. A.2 and A,3, the protection in the ultraviolet and infrared ranges is sufficient, Table I having been determined so that this should be the case. The use of a higher scale number would not necessarily provide better protection and would give in return disadvantages indicated in A.2.3.
A.2.2 If the use of filters selected from the tables produces a feeling of discomfort, the working environment and the eyesight of the operator should be examined.
A.2.3 It can be harmful to use filters with too high a scale number (too dark) as this would force the operator to move too dose to the radiation source and to inhale harmful fumes.
&2.4 For work carried out in the open air in strong natural light, it Es possible to use a protective filter of one scale number higher.