Scanning within range brings quick and constant decodes; scanning too close or too far away prevents decodes. Move the scanner closer and further away to find the right working range for the barcodes being scanned. However, the situation is complicated by the availability of various integrated scanning modules. The best way to specify the appropriate working range per barcode density is through a chart called a decode zone for each scan module. A decode zone simply plots working range as a function of minimum element widths of barcode symbols.
