Monitor’s TrueCap® Model
MK-2 RF capacitance point level sensor is designed
to provide a superior and stable sensitivity threshold
making it suitable for a variety of powder and bulk
solids, liquid and slurry applications. The available
split architecture design is ideal for applications
involving high temperature or vibration. The
probe and electronics are housed in separate enclosures
that are mounted apart for each other. This design
removes the electronics from the tough conditions.
For ease of use, the Model MK-2 has
push-button calibration and sensitivity selection as
well as a built-in automatic temperature compensation
circuit that combines with the MK-2’s microcontroller
to provide automatic calibration compensation yielding
the most stable and reliable RF capacitance point level
sensor available today. In addition, the Model MK-2
provides automatic immunity to material build-up on
the probe by its driven shield design and contains
a universal power supply of 48-240V AC / 24-48V DC.
The Model MK-2 can be combined with
the optional remote calibration module, which allows
you to interface with the MK-2 from up to 1,000 feet
(305 m) away from the sensor using an RS-485 connection.
The module can be placed near other control equipment.
This is ideal if your materials change often and the
material characteristics are so diverse that re-calibration
is required. It is also useful if your procedures require
probe functionality verification on a regular basis.
For more information, please visit www.monitortech.com
or call 1-800-601-5953 / 1-630-365-9403.
Monitor Technologies LLC, located
in Elburn, Illinois, is a leading manufacturer of level
measurement instrumentation, solids flow indicators,
particle emission monitors and aeration devices for
the worldwide powder and bulk solids markets. The experience
and market knowledge gained over 50 years of business
has earned Monitor a reputation for providing high
quality and reliable product solutions backed with
trusted customer service. For more information please
The TrueCap® Model MK-2
RF Capacitance point level probe is designed to provide a superior
and stable sensitivity threshold making it suitable for a variety
of powder / bulk solids and some liquid or slurry applications.
Advanced features of the Model MK-2 include: > Automatic immunity to material build-up on
the probe by its driven shield design > Push-button calibration > Enhanced temperature compensation > Maximized reliability via smart sensing algorithms
like “self-validating” fail-safe protection > Visible status LED on ordinary location units > Versatility through a variety of configuration
options including: hazardous location version, split architecture
design, quick-connect process connection, stub probe, cable extensions,
solid extensions, Nylon® probes, Ryton® - equiv. probes,
A practical application for the TrueCap would be to use this level sensor where
a residual material build-up on a different sensor would cause a false material
Principle of Operation for the TrueCap RF Capacitance Level
The vessel wall and the active probe element establish an impedance reference
between each other when exposed to air which has a dielectric constant of 1.
When materials with a dielectric constant greater than 1 are in close proximity
to the probe, the impedance of the sensing field between the sensor and the vessel
wall will change. Once the amount of change exceeds a threshold that was electronically
determined during the calibration process, an output relay will either be energized
or de-energized depending upon the position of the fail-safe selector on the
probe’s electronic circuit board. A change of as little as .5 pico-farad
is all that is necessary for the probe to sense the presence of material.