Microscan Quadrus EZ, Руководство пользователя, Страница: 327 / 366

Quadrus EZ Reader User’s Manual
A-23
Appendices
Appendix I — Determine Depth of Field
If symbols appear in the FOV at a consistent distance in your application, you could
simply set up for the recommended focal length and omit this test. However, if your
symbols appear at varying focal lengths, we recommend that you perform the follow-
ing test to determine the inner and outer read distances for your symbol type.
1. Position the symbol at the focal distance recommended on the back of your reader.
2. Position the symbol relative to the reader so that the distance to the reader can be
shortened or extended. Ideally, you should have the symbol mobile and the reader
mounted on a stand.
3. Move the symbol towards
the reader and away from
the reader until the decode
rate and/or green LED light
drops off in each direction
as shown in the illustration
on the right.
This will give you a sense of
the depth of field (inner and
outer ranges) for your sym-
bol’s density and focal dis-
tance.
Note: Depth of field will vary according to lens type. Typically, the narrow and
medium lens type readers will have less depth of field than the wide and extra wide
readers.
Dept
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