Pentax PLP-601 Instruction Manual page 31

[Direct marking]
After the reference level has been detected, mark a line along the
detector's index, or its top or bottom end.
[Plain rod marking]
After the reference level has been detected, mark a line along the plain
rod's top or bottom end.
NOTE:
• If a line was marked along the detector's top or bottom end, be sure to
make measurement compensation as described on the back of the
detector.
• The detector should previously be positioned correctly on the plain rod
according to the reference mark.
[Plain rod marking]
After the reference level has been detected, mark a line along the plain
rod's top or bottom end.
6
31