704-5010-130 Datasheet, PDF (20/36 Pages) Magnetrol International, Inc. – GuidedWave Radar Level Transmitter

A reflection is
developed off the
liquid surface
17
2.7.4 HART Revision Table (Model 704)
HART Version
Dev V1 DD V1
HCF Release Date
January 2003
Compatible with 704 Software
Version 1.0A and later
3.0 Reference Information
This section presents an overview of operating the Horizon
Guided Wave Radar Level Transmitter as well as informa-
tion on troubleshooting common problems, listings of
agency approvals, lists of replacement parts, and detailed
physical, functional, and performance specifications.
3.1 Description
Horizon is a loop-powered two-wire, 24 VDC, level trans-
mitter based on the concept of Guided Wave Radar.
Guided Wave Radar (GWR) is a relatively new level mea-
surement technology.
The Horizon electronics are housed in a single compart-
ment housing available in either cast aluminum or Valox.
3.2 Theory of Operation
3.2.1 Micropower Impulse Radar
GWR combines TDR (time domain reflectometry),
ETS (equivalent time sampling) and modern low power
circuitry. This synthesis of technologies brings to the level
market a high-speed radar circuit (speed of light transmis-
sion) at a small fraction of the cost of conventional radar.
The electromagnetic pulses are propagated via a waveguide
that yields a system many times more efficient than
through-air radar.
24 VDC, 4-20 mA
Loop Powered
Transmit
Pulse
Air ε_r = 1
Media ε_r > 1.7
A small amount of energy
continues down the probe
in a low dielectric fluid,
e.g. hydrocarbon
57-603 Horizon Guided Wave Radar Transmitter