REA
VERIFIER
© REA Elektronik GmbH, 64367 Mühltal, Germany --- REA MLV-2D Manual Version 3 – 21/12/2015
Page 87 of 98
12.1
Permissible device tolerances
The individual measured values of the check measurements must each be compared
with the corresponding reference values.
The requirements for measurement accuracy are specified in the standards ISO/IEC
15426-2 for matrix code verifiers and ISO/IEC 15426-1 for barcode verifiers.
The following data must be examined in order to make sure that the correct symbol
has been used with the settings for test equipment monitoring.
Other measurement
data and threshold values also shown on the verification report in this
context must be ignored for the purposes of this check.
Aperture
1
16 mil, 0.406 mm
Light type
660 nm under a 45° angle from all
four sides
Symbol
Pass 4.0
Symbology
Data Matrix ECC200
Code content
30Q324343430794<OQQ
The following table lists the criteria that must be verified according to ISO/IEC 15426-
2.
Measurement parameter
Unit
Tolerance
Reference
Rmax (see histogram)
2
%
+/- 5%
reflectance
Measurement
values on the
stamped
reference
verification
report
Rmin (see histogram)
3
%
+/- 3%
reflectance
UEC
4
%
+/- 0
Grid non-uniformity (GN)
%-
+/- 6 %(0.06 )
Axial non-uniformity (AN)
%-
+/- 2% (0.02)
Contrast uniformity
(modulation,
see paragraph. below)
%
+/- 8%
Fixed Pattern Damage (FPD) Degree +/- 0
In the ISO/IEC 15426-2 standard, the parameter "Modulation" is named instead of
contrast uniformity. This is also correct in the sense of the check made but difficult to
follow as a term. A footnote in the standard (ISO/IEC 15426-2) states that this is a
percentage value. This percentage value references the contrast uniformity reported
for the test symbol 5, "Black Widow" (see the card with REA part number 08300911).
Contrast uniformity is one specific value of many that are used to determine the
modulation value for the entire symbol.
1
Aperture – The synthetic aperture used, as defined by ISO/IEC 15415
2
Rmax – Maximum reflectance in the symbol, as determined by ISO/IEC 15415
3
Rmin – Minimum reflectance according to ISO/IEC 15415
4
UEC – Unused Error Correction as defined by ISO/IEC 15415
