28
58-601 Pulsar
®
Radar Transmitter
The exact level measurement is extracted from false target
reflections and other background noise via the use of
sophisticated signal processing. The new PULSAR circuitry
is extremely energy efficient so no duty cycling is necessary to
accomplish effective measurement. For this reason, PULSAR
can track high rates of change that were heretofore impossible
with existing loop-powered radar transmitters.
3.2.2 Equivalent Time Sampling
ETS, or Equivalent Time Sampling, is used to measure the
high speed, low power EM (electromagnetic) energy. ETS is
a critical key in the application of Radar to vessel level
measurement technology. The high speed electromagnetic
energy (1000 ft/µs) is difficult to measure over short dis-
tances and at the resolution required in the process industry.
ETS captures the EM signals in real time (nanoseconds) and
reconstructs them in equivalent time (milliseconds), which
is much easier to measure with today’s technology.
ETS is accomplished by scanning the tank to collect thou-
sands of samples. The round-trip event on a 65 foot (20m)
tank takes only 133 nanoseconds in real time. After it is
reconstructed in equivalent time it measures 200 milliseconds.
Tank
Height
Sensor Tank Height =
Distance from process
connection to tank bottom
20
4 mA
Sensor Reference Point
Sensor Offset (+)
Blocking
Distance
Distance
Safety Zone
Media
Level
Level Offset
Lowest
Measurable
Value