of the application; and (3) a variety of

Disturbances that

attenuate or distort the radar signal.

The Distance, or measurement range, is a function of

the instrument’s frequency and selected antenna, the

dielectric constant of the media, and the presence of

signal interference. Disturbances caused by turbulence,

foam, false targets (interior tank obstructions causing false

echoes), multiple reflections (reflections from off the tank

roof), or a high rate of level change, can weaken, scatter

or multiply radar signals. Very high and very low liquid

levels can also be problematic.

function is critically important because radar exhibits

interference effects similar to those that affect light. It is

the quality of a device’s signal processing that separates

today’s leading-edge radar transmitters from the others.

Most disturbances mentioned above can be readily

managed by Pulsar and Model R82 signal processing

capabilities where true level can be extracted from false

targets and other background noise. Using extremely

energy-efficient circuits, no duty cycling is necessary to

accomplish effective measurement. For this reason,

Magnetrol’s Pulse Burst Radar products can also track

high rates of change that have been impossible with other

loop-powered radar transmitters. Although these products

feature powerful False Target Recognition and Rejection

routines, minimizing false target reflections is significantly

affected by proper installation and orientation.

receives the radar signal. Pulsar offers dielectric rod and

horn types while the Model R82 uses an encapsulated horn

antenna. Maximum measuring range of the instruments is

chiefly dependent upon the instrument’s capabilities,

dielectric constants, and the degree of turbulence.

Dielectric constant, temperature, and pressure capabilities

for our radar products are shown on page 6.

provides the key steps for mounting, wiring and configur-

ing Magnetrol transmitters. Though transmitters come

configured from the factory, they can be reconfigured in

the shop. Bench configuration provides a convenient and

efficient way to set up the transmitter before going to the

tank site to complete the installation. The transmitter is

password protected to protect configuration values.

can be used to provide a communication link to the

Pulsar and R82 transmitters. When connected to the

control loop, the measurement readings shown on the

transmitter will be shown on the communicator. The

communicator can also be used to configure and trou-

bleshoot the transmitter. See page 11 for information on

PACTware, today’s leading configuration and diagnostics

software.

to measure a large number of liquid media in a broad

range of process conditions, from calm product surfaces

and water-based media to turbulent surfaces and aggres-

sive hydrocarbon media. As a non-contact device, these

products are not susceptible to the complications that

arise whenever a probe contacts the process media, such

as coating by viscous media or corrosive attack due to

aggressive chemicals. The greater the measuring range,

the more does radar prove itself to be the economical

solution, given the cost of extended probe lengths.

Radar is virtually unaffected by the presence of

vapors, or air movement within a vessel’s free space.

Changes in specific gravity, conductivity and dielectric

constants also have no effect on measurement accuracy.

As a 100% electronic instrument, the absence of moving

parts translates into low maintenance costs. As a two-

wire, loop-powered device, power requirements and

installation are greatly simplified.

I

4

‚

ƒ

„

Pulse Burst Radar technology and advanced signal pro-

cessing help manage common disturbances:

‚

False

echoes caused by obstructions, or multi-path reflections

caused by waves hitting a sidewall;

ƒ

Turbulence generated

by agitators or aggressive chemical reactions; and

„

A layer

of light to medium density foam.