Technical Articles, Case Studies and White Papers (Relating to level mesurement, solids
flow monitoring, particle emission detection, bin aeration
applications and more)
Advanced
Material Flow/No-Flow Detection Using Point Level Sensors,
Microwave Flow Detectors >>
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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 loc 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.