User's Manual

User Guide

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User Guide, WherePort IV D1300 REV A

Figure19 Coverage Pattern

A single (A), adjacent (B), and dual WherePort IV (C) field are shown. The fields shown are for

WherePort IVs at power level 8 and mounted at the same height as the WhereTag.

7.8. Interference

Steel objects and some devices can interfere with the WherePort IV field and change its shape and range.

Some kinds of structures will affect the range of the WherePort IV. Mounting the WherePort IV on the

broad face of a steel I-beam reduces the coverage on the front and back of the WherePort IV.

The field can also be extended or ducted by steel in windows, metal studs, conduit, or duct work. This is

most likely to occur when the WherePort IV is within one to two feet of the steel and the tag is also close

to the steel. This could lead to an unwanted increase in the size of the field.

Magnetic interference can block communication between the WherePort IV and the tag. The most

common sources of magnetic interference are CRT monitors, electric motors, vehicle RFID anti-theft

ignition systems, and other WherePort IVs. A WherePort IV may not ping a tag that is within one to two

feet of an operational monitor or industrial motor. The field strength meter can be used to check for

interference.