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The SonacŪ 110 provides the most reliable overflow
alarm or control available.
Where liquids to be sensed constantly change physical
or electrical properties. The SonacŪ 110 principle of
measurement is used with extremely small vessels or
pipes and when little or no intrusion into the process is
required.
Non-dedicated vessels - liquids
The device senses virtually any liquid and does
not need adjustment when the density or dielectric
constants are changed.
High temperature, High pressure service
The welded, all stainless steel sensor body is designed
for service at temperatures to 220°F (+104°C) and
pressures to 2,000 psig.
Fluids with foam blankets
The control ignores foam to indicate the true liquid level.
Principle Of Operation
The sensor is a magnetostrictive device consisting of a diaphragm,
nickel tube, magnet, drive coil and pickup coil.
When 40 kHz energy is applied to the drive coil, it causes the
diaphragm to vibrate at a frequency determined by the mechanical
resonant system of the sensor. Electrical energy is transferred to
the pickup coil when the diaphragm is free to move in gas. When
the diaphragm motion is loaded by a process material, less energy
is transferred to the pickup coil.
The pickup coil of the sensor is connected to the input of an amplifier
and the output of the amplifier to the drive coil to form a feedback
loop circuit. Any energy appearing in the output of the sensor
will be fed to the amplifier, amplified and returned to the input of
the sensor. This causes vibrations at 40 kHz to occur in the
diaphragm and furnish a signal back to the amplifier for reamplification.
When the gain of the amplifier is adjusted so as to exceed
the losses within the sensor, continuous oscillations are produced.
If the diaphragm of the sensor is exposed to a process liquid
product which offers greater mechanical resistance to the motion of
the diaphragm, the transfer of energy to the pickup coil decreases.
This results in a decrease in the signal feedback into the amplifier
and a corresponding decrease in the signal available from the
output of the amplifier. The decreased signal triggers a voltage
sensitive network that controls the output relay.
A unique AUTO TEST self-checking circuit constantly verifies the
integrity of the sensor circuits. The RED LED is illuminated when
the product is absent at the sensor and the system is oscillating at
approximately 40 kHz. If the amplitude or the frequency of the
sensor circuits changes, the RED LED will go out. If the change of
state occurs due to a level change, the relay will follow and change
its state. However, if the change of state is due to a sensor
failure or some other component failure, the relay will immediately
transfer to the alarm condition. This foolproof feature protects the
system for loss of power, major component failure or damaged sensor conditions. The SonacŪ 110 system will
fail-safe for all sensor or component failures except for open sensor
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