Vibratory
Level Indicator Is Ideal For Materials With
Lower Bulk Densities
The Model
PZP vibrating style point level sensor provides
exceptional sensitivity for detecting bulk solid
materials with a density as light as 1.25 lbs./ft.3 (pounds
per cubic foot) where other sensor technologies might
be ineffective. Additionally, the PZP does not require
calibration and uses a unique diamond shape single
element that is immune to material packing and bridging,
unlike traditional tuning forks. Plus, it has no
mechanical moving parts.
The Model PZP is also designed for versatility. It's
ideal for situations where the range of bulk density,
particle sizes, humidity levels, and/or dielectric constants
of the materials being stored or collected (dust collection
systems) varies widely. This can be a challenge for many
level sensor technologies; however, the PZP is capable
of detecting bulk solid materials with a density as light
as 1.25 lbs./ft.3 all the way up to 100 lbs./ft.3.
The Model PZP vibrating point level sensor uses dual
piezoquartz crystals. These crystals respond to electrical
excitation by vibrating, which results in the vibration
of the sensing element at about 280Hz. The uniqueness
of the PZP's diamond shape sensing element and electronics
provides the sensitivity to detect very lightweight materials,
in addition to heavier materials. Applications
for use include high and low level indication and as
a back-up for dust collection systems. Typical materials
include plastics, cement, fly ash, chemicals, lime, clay,
sawdust, food, flour, rice, cereal and more.
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
visit www.monitortech.com.
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.