Tag Archive for: Hopper

Silo Load Monitoring



Plant operators need to continuously measure bulk material levels/weight in their silos and hoppers to ensure their processes are running safely, efficiently, and without bottlenecks. Measuring these levels allows operators to automate vessel filling, verify material consumption, and prevent overfilling.

What we offer

ITM provides its customers with a variety of structural load monitoring systems. Using strain gauge based transducer technology, ITM can design and implement a real-time system to continually monitor load responses of the supporting members on an array of structures.

Strain gauge based measurements are more accurate and typically less expensive than load cell retrofitting. The addition of a monitoring system can also reduce the risks associated with manual measurements including contamination of product and, more importantly, injury to a worker.  

How do you measure bulk material levels/weights in silos and hoppers?

The two ways to measure bulk material quantity in silos/hoppers are level indicators (laser, ultrasonic, radar) and weight measurements (load cells, strain gauges).  Weight measurements are more accurate, safer to install, and can be installed during operation.  Of the types of weight measurements, ITM prefers to implement strain gauge-based solutions since they do not require structural modification of the vessel.

An ITM silo monitoring system typically consists of weatherproofed strain gauges for each silo leg and a NI CompactRIO embedded controller to acquire data, process signals, and output results. Systems are scalable to accommodate all the silos at the plant.

The graph above shows a typical trend of real silo data during unloading.  Weight levels are sent directly to factory DCS systems and historians via common communication protocols like Ethernet/ip and Modbus, or they can be viewed on the system’s webpage or a local/remote workstations and panels.

What are the challenges when measuring bulk material levels/weights?

Most bulk material storage is outside, so temperature and other environmental factors must be accounted for not only in the durability of the equipment, but in the sensor design and data processing. Changes in temperature, wind, and humidity can result in changes to the load path in silo legs. Load changes are account for by instrumenting all or most of the silo legs and selecting the appropriate strain gauge bridge design which results in continuously accurate weight measurements.

While other systems require calibrating the system with known loads (point calibration), ITM calibrates the system using a shunt voltage across the strain gauge bridge. This process automatically calibrates the system and eliminates the requirement of having pre-known material weight added to the vessel.

For more information about silo monitoring, contact Ryan Matthews @ 1.844.837.8797 x706.  To see how ITM’s structural load monitoring systems work watch this video below.

AF & PA Conference 2017: ITM presents HALT boiler safety technology

Come watch ITM’s president Tim Carlier (tim.carlier@iTestSystem.com) present on a new boiler safety system, Hopper Ash Level Thermocouple (HALT) monitoring system, at the 2017 American Forest & Paper Association (AF & PA) Meeting and Conference in Atlanta, GA this February.  Tim will describe how this system predicts Ash Hopper pluggage and warns boiler operators when a dangerous situation exists.

ITM will also introduce new boiler and plant optimization technologies/systems that their partners have used to streamline processes.

Conference details can be found at https://www.afandpa.org/our-industry/recovery-boiler-program

Find out more about ITM’s Boiler Monitoring Solutions https://itestsystem.com/solutions/industrial-monitoring-systems/

Wireless Strain Based Silo Monitoring

Silo Level Monitoring Video

Keeping up with more than a million pounds of plastic pellets a year would seem a near impossible task.

But at ITM, we’ve developed a wireless strain based monitoring solution to help manufacturers — particularly those in the injection mold business — easily alter existing storage silos to keep a more accurate eye on the levels of dry goods contained in them.

Industry partners report the difficulty of keeping exact measurements of the amount of ever-changing raw materials they have stored in on-site silos. With our solution, however, we’ve removed the guesswork with a system that won’t require manufacturers to go through costly structural modifications.

As we demonstrate in this video, we are able to build a measurement system that will report silo levels by using strain gauge sensors, a wireless signal transmitter and a remote signal receiver. Notice in the lab test, as the valve is opened and the water begins to drain, the signals on the user interface respond accordingly as the values decrease. Though a seemingly simple test, I’m convinced the results hold important real-world implications.

Similarly, we think manufacturers will value being able to monitor multiple silos from a single customized interface and ultimately maintain efficiencies and keep their production lines humming.

— ITM President Tim Carlier