Emerson Rosemount Apex User Manual

Reference Manual
00809-0100-4731, Rev FA
April 2003
APEX
™
and APEX Sentry
™
Radar Gauge
www.rosemount.com
Appendix A Reference Data
Antenna Selection Guidelines . . . . . . . . . . . . . . . . . . . . . . page A-1
Telecom Restrictions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . page A-2
Equipment Description . . . . . . . . . . . . . . . . . . . . . . . . . . . page A-4
Performance Specifications . . . . . . . . . . . . . . . . . . . . . . . page A-4
Environmental Conditions . . . . . . . . . . . . . . . . . . . . . . . . . page A-5
Electrical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . page A-5
Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . page A-7
Software Functionality . . . . . . . . . . . . . . . . . . . . . . . . . . . . page A-7
Weight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . page A-7
Materials of Construction . . . . . . . . . . . . . . . . . . . . . . . . . page A-8
Dimensional Drawings . . . . . . . . . . . . . . . . . . . . . . . . . . . . page A-9
Ordering Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . page A-12
ANTENNA SELECTION
GUIDELINES
Selecting an antenna size can be as simple as matching the available
process opening to the antenna size. However, when selecting an antenna,
consider the following:
• A larger antenna will yield the strongest, most concentrated signal.
Fluids with low dielectric constants, such as many hydrocarbons and
solvents, only reflect a small portion of the radar signal. A more
focused beam that is provided by a larger antenna will yield a stronger
signal. This is especially important as the distance to the fluid
surface increases.
• Ideally, the beam should not be obstructed by the sides of the vessel or
any other equipment in the tank. Consult the beamwidth table to
determine the size of the beam at its maximum expected distance
(lowest tank level). Since beamwidth decreases as the antenna size
increases, the beam from a larger antenna is least likely to encounter
obstructions.
• In stilling wells and bypass assemblies, the pipe will prevent dispersion
of the beam and will yield a very concentrated signal. In those
situations, a smaller antenna is suitable. The use of stilling wells may
impact the accuracy.
• In general, 3-in. and 4-in. antennas can be used in nozzles that have
an unobstructed total length of up to 1 m (39 in.). It is recommended
that 2-in. antennas be used only in nozzles where the total length is
less than 0.35 m (14 in.). Consult the factory for assistance with
exceptions.

Emerson Rosemount Apex Specifications

General

Brand	Emerson
Model	Rosemount Apex
Category	Measuring Instruments
Language	English