GA/T 1690.2-2019Forensic sciences--Examination methods for seal stamps -- Part 2: Overlapping and comparison (English PDF)

Foreword

GA/T 1690 "Forensic Science Seal Seal Test" is divided into 6 parts.

---Part 1: Microscopic inspection method;

---Part 2: Coincidence comparison method;

---Part 3: Detailed feature comparison method;

---Part 4: Measurement comparison method;

---Part 5: Splicing comparison method;

---Part 6: Line drawing comparison method.

This part is part 2 of GA/T 1690.

This section was drafted in accordance with the rules given in GB/T 1.1-2009.

This part is proposed by the National Criminal Technology Standardization Technical Committee Document Inspection Sub-Technical Committee (SAC/TC179/SC10) and be in charge.

1 Scope

This part of GA/T 1690 stipulates the method specification for the inspection of seal seals by the coincidence comparison method in the field of forensic science.

This section applies to the inspection of seals and seals in the field of forensic science.

2 Equipment

Light-transmitting board, comparison microscope, graphics (image) processing software with coincidence comparison function, document inspection instrument, copier, scanner, camera, etc.

3 Inspection

4 Make inspection records

The inspection result of coincidence comparison shall be recorded in the inspection record. If necessary, you can place the overlapping comparison pictures, and the details of the overlapping parts Label or text description of the form, relative position, etc.

5 Matters needing attention

5.1 Should be combined with the material of the seal, the method of inking, the storage conditions, the use conditions, the use time, the folding of the printed text, the paper stains and other factors Analyze the similarities and differences of coincidence.

5.2 When using translucent coincidence comparison, in order to enhance the comparison effect, the printed text can also be copied to a transparent or translucent carrier at the same magnification Comparison.

5.3 When using graphics (image) processing software for registration and comparison, the deviation of the picture during the collection process (such as scanning deviation, camera shooting angle)