|
Spotlight: RF Capacitance Level Sensor
 |
|
  |
|
TrueCap® MK-2
Advanced RF Capacitance Level Probe |
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,
etc.
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
level indication.
Principle of Operation for the TrueCap RF Capacitance Level
Probe:
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.
Click
here for more information on the TrueCap MK-2 Level Sensor or
contact Monitor Technologies LLC at
Tel.: 800-766-6486 in the USA and
Tel.: 630-365-9403 worldwide.
|
 |
|
|
| |
|
|
|
|
 |
|
 |
 |
|
animal
feeds. The level sensing in
each of the Whey Permeate tanks and the liquid tank needed
to be reliable and accurate.
All three (3) Flexar units worked fine right from the start. Ross
Jamison was able to help out with the quick setup on the Flexar displays
and the Flexar units were inserted and installed with material still
in the tanks. Once everything for the start-up was completed
Tom Campbell of Socorro Design got back on top of the tanks and checked
the level and they were found to be "dead on". Everyone
was very happy and pleased with the Flexar units and their simple
installation. The level readings are connected to an A-B Panelview
inside the facility. The entire process of loading and unloading
the whey tanks will be automated and the level readings from Flexar
are key. More installations like this will be considered by
Westway using Flexar in the future.
Flexar is a guided wave radar continuous level sensor. Distance/level
is measured by the time-of-flight of the reflection of a microwave
signal (transmitted down the wave-guide, which is the cable or rod
probe) off the material surface. For more information refer
to 