( click here )

July 2009: SiloPatrol® SE
SiloPatrol® Celebrates 10th Anniversary
SiloPatrol® SMU - 1999
SiloPatrol® SE - 2009
SiloPatrol® SMU - 1999
SiloPatrol® SE - 2009


On July 22, 1999, a day before the Space Shuttle Columbia launched with the first female shuttle Commander - Eileen Collins, the first SiloPatrol® SMU level sensor was shipped out from Monitor Technologies’ Elburn, IL facility.  It was among the industry’s first electronically controlled “smart” cable-based level sensors. Ten years later, the SiloPatrol is still an industry-leading continuous level sensor. Since the original unit, the SiloPartol has evolved into the Second Edition (SE) with product enhancements like a sealed split compartment design, a serviceable wiper seal compartment, enhanced motor control features, and unique lock-out circuitry which if utilized prohibits a sensor from making a measurement when activated.  

The SiloPatrol® SE is a rugged, reliable and accurate level measuring system designed for the harshest and most dynamic conditions. It is effectively used to improve material inventory control of powder / bulk solids and many liquids in storage silos, hoppers, vessels, etc. The sensors measure the inventory level automatically and on-demand without the need for your operator or plant personnel to climb silos. The smart cabled-base sensors automatically lower a weight & cable into the silo until it contacts the material surface. Upon contact the weight & cable system is immediately retracted and the measurement is fed to the plant control system or operator interface. A microcontroller directs all of the functions of the sensor to ensure the proper travel of the weight & cable, which provides accuracy and reliability of the measurement. These sensors are easy to install and are also virtually maintenance free, requiring only a periodic inspection usually once or twice per year. Once the material level measurement is obtained, a variety of operator interface devices is available to calculate and display material volume, weight and more. A PC-based software package is also available that can automate report generation, send emails to suppliers or corporate locations and allow remote viewing of material level inventory. Please visit for more details.

About Monitor

Monitor Technologies LLC is a pioneering supplier of level measurement instrumentation, solids flow monitors, 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. Monitor is located in Elburn Illinois.

For more information please visit, and our blog at You can also contact Mr. Greg DeRudder or Mr. Chris Otte of Monitor Technologies at 1-800-766-6486 in the USA or 1-630-365-9403.


Spotlight: RF Capacitance Level Sensor
TrueCap Level SensorsTrueCap Light  
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.


>>Download TrueCap Product Bulletin #413

>>Click here to learn more about other Point Level Switches from Monitor Technologies


Join Monitor's E-Mailing List!
Enter your Email Address Here:



© 2022 • Monitor Technologies, LLCAll Rights Reserved
Privacy / Cookies Policy & Terms
1.800.601.6319 or 1.630.365.9403

  Translate This Web Page:
Translate text and documents.