The Reserve Bank of India (RBI) has released a new master circular on note sorting machines.
(i) Soiling
Soiling refers to the general distribution of dirt across the entire note or in some patterns. It is a measure of the loss of reflectivity from the unprinted areas due to dirt, ageing (yellowing), wear and extraneous markings and includes decolouration due to ageing, excessive folding and other wearing. Soiling increases the optical density and decreases the reflectance of the notes. Notes exceeding the soiling levels set out in Table below shall be sorted as unfit. Both the obverse and the reverse of the note shall be checked for soiling.
Table: Soiling Levels
| Sl. No. | Denomination | Maximum Density difference | Minimum Reflectance |
|---|---|---|---|
| 1 | ₹5 | 0.07 | 85% |
| 2 | ₹10 | 0.07 | 85% |
| 3 | ₹20 | 0.06 | 87% |
| 4 | ₹50 | 0.06 | 87% |
| 5 | ₹100 | 0.05 | 90% |
| 6 | ₹200 | 0.05 | 90% |
| 7 | ₹500 | 0.04 | 93% |
(ii) Limpness
Limpness relates to structural deterioration or wear resulting in a marked lack of stiffness in the note paper.
(ii) Limpness
Limpness relates to structural deterioration or wear resulting in a marked lack of stiffness in the note paper. Notes with very low stiffness of paper, i.e. with paper which is worn out in circulation or mechanically mutilated shall be sorted as unfit. Detectors for paper quality shall be adapted to the same level as for soiling.
(iii) Dog-Ears
Banknotes with dog-ears with an area of more than 100 mm² and a minimum length of the smaller edge greater than 5 mm shall be sorted as unfit. Chipped notes shall also be sorted as unfit.
(iv) Tears
Notes exhibiting at least one tear at the edge shall be classified as those having tears. Notes with tears larger than those indicated in Table 3 shall be sorted as unfit.
Table: Tears
| Sl. No. | Direction | Width | Length |
|---|---|---|---|
| 1 | Vertical | 4 mm | 8 mm |
| 2 | Horizontal | 4 mm | 15 mm |
| 3 | Diagonal * | 4 mm | 18 mm |
- Measured by drawing a straight line from the peak of the tear to the edge of the note where the tear begins (rectangular projection), rather than measuring the length of the tear itself.
(v) Holes
This refers to notes with at least one visible hole. Notes with holes with area exceeding 8 mm² shall be sorted as unfit.
(vi) Stains
Stains are visible markings which are not part of the feature of a note. Notes shall be detected as unfit if localized – i.e. with limited extension – stain can be recognized on its surface. In case the total area covered by stains exceeds 500 mm², the note shall be sorted as unfit. A note with a single stain covering an area of more than 200 mm² shall be sorted as unfit. Both the obverse and the reverse of the note shall be checked for stains.
(vii) Graffiti
Graffiti refers to deliberate graphic alteration of the note with for example, figures or letters. Non-permanent markings such as pencil scribbles, which do not obscure the banknote subject to passing the criteria for reflectance and optical density, may not be classified as unfit. Fitness sorting criteria in case of graffiti shall be the same as those for stains. Both the obverse and the reverse of the note shall be checked for graffiti.
(viii) Crumples / Folds
Crumpled / folded notes shall be sorted as unfit if the folds result in reduction of the original note in length or width greater than 5 mm.
(ix) Decolouration
Notes affected by decolouration shall be sorted as unfit if the ink is partially or wholly missing from its surface. Both the obverse and the reverse of the note shall be checked for decolouration.
(x) Repair
A repaired note is created by joining parts of the same note together, for example, by using extraneous matter such as tape, paper or glue. Notes with the following types of repairs shall be sorted as suspect / reject:
• Repairs covering an area greater than 100 mm²; or
• Thickness of the extraneous matter 50 μm or more; or
• Width of the extraneous matter 10 mm or more; or
• Length of the extraneous matter 10 mm or more.
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Click here to download RBI Circular on Note Sorting Machine
