Orion Instruments Eclipse 705 - Manual (Page 40)

40 57-600 Eclipse ® Guided Wave Radar Transmitter
FISCO certifying agencies have limited the maximum
segment length to 1000 meters because the FISCO model
does not rely on standardized ignition curves.
The ECLIPSE Model 705 is available with an entity IS,
FISCO IS, and explosion proof approvals.
3.0 Reference Information
This section presents an overview of the operation of the
ECLIPSE Guided Wave Radar Level Transmitter, information
on troubleshooting common problems, listings of agency
approvals, lists of replacement and recommended spare
parts, and detailed physical, functional, and performance
specifications.
3.1 Description
ECLIPSE is a loop-powered two-wire, 24 VDC, level transmitter
based on the concept of Guided Wave Radar. Guided Wave
Radar, or Micropower Impulse Radar (MIR), is a revolutionary,
new level measurement technology.
The ECLIPSE electronics are housed in an ergonomic hous-
ing comprised of two tandem compartments angled at a
45-degree angle for ease of wiring and calibration. These
two compartments connect via an explosion proof and
watertight feed-through.
3.2 Theory of Operation
3.2.1 Micropower Impulse Radar
MIR (Micropower Impulse Radar) 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 transmission) at a small fraction of the cost of conven-
tional radar. The electromagnetic pulses are propagated via a
waveguide that yields a system many times more efficient
than through-air radar.
A small amount of energy
continues down the probe
in a low dielectric fluid,
e.g. hydrocarbon
Air
ε
r = 1
Media
ε
r > 1.4
24 VDC, 4-20 mA
Loop Powered
A reflection is
developed off the
liquid surface
Transmit Pulse