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MN301905 Rev A
Introduction / Table of Contents (continued)
Step One
OPERATING PRINCIPLE
The sensor emits a microwave pulse from its antenna, which travels at the speed of light to the surface of the
medium below. A portion of that energy reflects off the medium and returns to the antenna. The time gap
between energy emission and receipt is called the “time of flight”, and is proportional to the distance between
the medium surface and the sensors measurement location, as at the bottom of the antenna. The sensor
measures the time of flight and translates this value into a continuous 4-20mA signal output that’s
proportionate to level within a defined measurement span.
FEATURES
Easy configuration with LCD push button display module
Adjustable loop fail-safe, no change, 20.5 mA, 22 mA
Small 12” (30.48cm) dead band enables full tank measurement
Recognition, storage and deletion of false echo signal returns
BENEFITS
Unaffected by physical process and environmental conditions
Ideal for applications with higher temp, pressure, foam, vapor and vacuum
Strong signal penetrability with minimal attenuation over distance
LIMITATIONS (FACTORS THAT COULD INFLUENCE PERFORMANCE)
Air particulates with a high dielectric constant value such as lead or ferroalloy
Highly dense air particulates that attenuate microwave emission and receipt
Material build-up on the antenna that degrades microwave emission and receipt
Mediums that have an extremely low dielectric constant value with little reflectivity
