 |
 |
 |
Quiet zones |
 |
|
| Non-printed zones immediately before and after the barcode. It is recommended that the quiet zone be at least 10 times the narrow bar width. A quiet zone smaller than this can make the barcode unreadable. |
 |
| Note: |
Insufficient quiet zones will cause inaccurate readings. Please make sure to secure enough quiet zones for all bar codes. |
|
|
 |
Start/Stop character |
 |
|
A pattern of bars and spaces that provides the scanner with start and stop reading instructions. For example, Code 39 uses "*" as a start and stop character.
|
 |
Data (Message) |
 |
The bar patterns which are represented as data by numbers or letters are placed from the left. For example, in the above figure, the bar patterns representing "0", "1", and "2" in sequence from the left represent the data "012". |
 |
Check digit |
 |
| A digit included within a barcode whose value is used
to perform a mathematical check that ensures the
accuracy of the read. It is placed immediately after the
barcode data. |
 |
Label length |
 |
| Length of label including left and right quiet zones. A
read cannot be made if the quiet zones are not large enough. |
 |
Barcode height |
 |
| The height must be at least 2 mm (0.08") for a single line
option and at least 5 mm (0.20") for a raster option. |
 |
Narrow bar width |
 |
Barcodes consist of bars and spaces of different width.
The bars and spaces are called out as follows: |
 |
 |
 |
The wide bar width is determined according to
the narrow bar width. The standard ratio is:
|
 |
The width of the narrow bar is called narrow bar width.
The narrow bar width is used as the Specification
Standard of Bar Code Readers. |
 |
 |
When narrow bar width is small |
 |
More information can be places in the barcode in limited spacing due to smaller bar widths. |
 |
Scan width becomes narrow (read range becomes small). |
 |
High quality barcode printing is required (laser and thermal transfer printers). |
|
 |
 |
When narrow bar width is wide |
 |
The barcode will be wider. |
 |
Scan width becomes wide (read range becomes large). |
 |
High quality barcode printing is slightly less important. |
|
|
|