Scantron OpScan 4ES Operator's Manual page 225

Operator's Guide
problem is caused by the sensor head not being
positioned the correct distance from the sheet or
form that is in the transport bed.)
Make certain that the sheet deflector on the
scanner is in the full down position. If you can't
resolve the issue, continue with step 2.
NOTE: Positions 25 and 80 contain bar codes that
are 7 thousandths of an inch wide—the most
difficult to read. If the bar code reader can read
both positions 25 and 80 correctly, other posi-
tions on the diagnostic sheet should also read
correctly.
2.
If your bar code reader cannot read positions 25
and 80, try scanning positions 30 and 75.
If your bar code reader cannot read positions 30
and 75 there may be a problem with your bar code
diagnostic form. Replace the form(s) if necessary
and attempt to scan positions 30 and 75 again.
If your bar code reader can read both positions 30
and 75 correctly, the problem lies with your bar
code reader. Contact Scantron Customer Support
as described in "Product Support and Services" on
page 157.
NOTE: Positions 30 and 75 contain bar codes that
are 10 thousandths of an inch wide—the least
difficult to read.
Chapter : Bar Code Reader
Testing the Bar Code Reader
205