NEN EN 1635 : 1997

Foreword
Introduction
1 Scope
2 Normative references
3 Definitions, symbols and abbreviations
    3.1 Definitions
    3.2 Symbols and abbreviations
          3.2.1 Abbreviations
          3.2.2 Symbols used in formulae
4 Measurement methodology
    4.1 General requirements
    4.2 Correlation with traditional methodologies
    4.3 Reference reflectivity measurements
          4.3.1 Measurement wavelength(s)
          4.3.2 Optical geometry
          4.3.3 Sample area
          4.3.4 Inspection band
          4.3.5 Number of scans
          4.3.6 Process control for repetitive printing
    4.4 Scan reflectance profile
    4.5 Profile assessment parameters
          4.5.1 Element determination
          4.5.2 Decode
          4.5.3 Symbol contrast
          4.5.4 Edge contrast
          4.5.5 Modulation
          4.5.6 Defects
          4.5.7 Decodability
          4.5.8 Quiet zone check
5 Symbol grading
    5.1 Scan reflectance profile grading
          5.1.1 Decode
          5.1.2 Reflectance parameter grading
          5.1.3 Decodability
    5.2 Expression of symbol grade
6 Other aspects of the symbol
    6.1 Substrate characteristics
    6.2 Element widths
          6.2.1 Average element widths
          6.2.2 Process control for 'EAN/UPC' symbols
    6.3 Correlation of symbol contrast with other
          contrast measurements
7 Multi-row symbologies
Annexes
A (normative) Decodability
    A.1 Applicable symbologies
    A.2 'Code 39' and 'Interleaved 2 of 5'
    A.3 'Codabar'
    A.4 'Code 128'
    A.5 'EAN/UPC'
B (informative) The relationship between bar width
    deviation and decodability for the 'EAN/UPC'
    symbology
    B.1 The V2 factor
    B.2 Bar width deviation and decodability
C (informative) Example of symbol quality grading
    C.1 Individual scan reflectance profile grading
    C.2 Overall symbol grade
D (informative) Substrate characteristics
    D.1 Substrate opacity
    D.2 Gloss
    D.3 Over-laminate
E (informative) Interpreting the scan reflectance profile
    and symbol grades
    E.1 Significance of scan reflectance profiles
    E.2 Interpretation of results
    E.3 Grades for process control
    E.4 Matching grades to applications
    E.5 Alphabetic grading
F (informative) Static reflectance measurements
G (informative) Guidance on selection of measurement
    wavelength
    G.1 Light sources
    G.2 Effect of variations in wavelength
H (informative) Guidance on number of scans per symbol
J (informative) Example of verification report
K (informative) Contrast measurements - Comparison of
    symbol contrast with print contrast signal

Defines methodology for testing bar code symbols for conformity with symbology specification, specifies a range of quality grades based on measuring specified attributes of the symbol and provides information on possible causes of deviation from optimum grades to enable users to take appropriate corrective action.