Fujitsu fi-4120C2 Operator's Manual page 56

The following detection conditions are provided:
None
Check thickness
Check length
Check thickness and length
Furthermore, see "6.5 Multi feed Detection Conditions" (page. 91) for detailed information
about the document for multi feed detection.
4. Click the [OK] button.
The display returns to the [TWAIN Driver] dialog box. Continue scanning from this dialog
box.
40
: Multi feed detection is not performed.
: The scanner monitors the thickness of documents. It detects a multi
feed by differences in document thickness when two or more docu-
ment sheets are fed overlapping.
: The scanner monitors the length of documents. It detects a multi
feed by changes in the document length when two or more document
sheets are fed overlapping.
: The scanner monitors both document thickness and length to detect
multi feed.