EN 379:2003+A1:2009

Foreword
1 Scope
2 Normative references
3 Terms and definitions
4 Requirements
  4.1 General requirements
  4.2 Particular requirements
  4.3 Additional requirements
      4.3.1 Power off
      4.3.2 Transmittance
      4.3.3 Variations in luminous transmittance
      4.3.4 Switching time
      4.3.5 Manual control of dark scale number
      4.3.6 Diffusion of light
      4.3.7 Angle dependence of luminous transmittance
  4.4 Spectral sensitivity of welding filters with
      automatic scale number setting
  4.5 Viewing area
5 Test methods
  5.1 Power off test
  5.2 Measurement of switching time
      5.2.1 Test equipment
      5.2.2 Performance of test equipment
      5.2.3 Measurement
      5.2.4 Calculation
  5.3 Scale number setting of welding filters with automatic scale
      number setting
      5.3.1 Test equipment
      5.3.2 Measurement of the scale number setting
  5.4 Spectral sensitivity of welding filters with automatic
      scale number setting
      5.4.1 General
      5.4.2 Method using monochromatic radiation
      5.4.3 Method using cut-off filters
  5.5 Angle dependence of luminous transmittance
  5.6 Test schedule for type examination
6 Marking
  6.1 General
  6.2 Automatic welding filters and automatic welding filters
      with manual scale number setting
  6.3 Welding filter with automatic scale number setting
7 Information to be supplied by the manufacturer
Annex A (informative) Guidance on selection and use
        A.1 General
            A.1.1 Scale numbers to be used for gas welding
                  and braze welding
            A.1.2 Scale numbers to be used for oxygen cutting
            A.1.3 Scale numbers to be used for plasma jet cutting
            A.1.4 Scale numbers to be used for electric arc welding
                  or air-arc gouging
            A.1.5 Scale numbers of filters to be used by welders'
                  assistants
        A.2 Remarks
Annex B (informative) Uncertainty of measurement and results
        interpretation
        B.1 Test report and uncertainty of measurement
Annex ZA (informative) Clauses of this European Standard addressing
         essential requirements or other provisions of EU Directives
Bibliography

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.