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 Aysix
Ultrasonic Level Measurement Instruments use sound waves to determine
level. A piezoelectric crystal inside the transducer mounted on
top of the tank converts electrical pulses into sound energy that
travels in the form of a wave at the established frequency and
at a constant speed in a given medium. The sound waves are emitted
in bursts and received back at the transducer as echoes. The Ultrasonic
Level Measurement Instrument measures the time for the bursts
to travel down to the reflecting surface and return. This time
will be proportional to the distance from the transducer to the
surface and can be used to determine the level in the tank.
An ultrasonic gap technique is an alternative way to measure point
level with low-viscosity liquids. A transmit crystal is activated
on one side of a "measurement gap" and a receive crystal
listens on the opposite side. The signal from the receiving crystal
is analyzed for the presence or absence of tank contents in the
measurement gap.
Ultrasonic Level Measurement Technology
Advantages:
- No moving parts
hence no wear and tear
- Non-contact
technology
- Easy Calibration
Ultrasonic Level Measurement Technology
Disadvantages:
- Affected by
powders, heavy vapors, surface turbulence and foam
- Cannot operate
in vacuum or high pressure
- Needs good reflective
surface
- More position
sensitive than other technologies
- Can be affected
by vapors, structural members, foam
- Limited temperature
& pressure range
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