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.
A case study describing a strain gauge DAQ system used to validate several new designs of a heavy lift lattice boom crane to comply with SAE J987 standards.
https://itestsystem.com/wp-content/uploads/2020/07/IndustrialProcess.jpg6281200Mark Yeagerhttps://itestsystem.com/wp-content/uploads/2020/05/itmlogo_Horizontal_3x1.pngMark Yeager2020-07-08 10:00:002023-07-26 18:06:27Process Optimization with Embedded Monitoring Systems
Sang-Soo Kim is used to overcoming bumps in the road. After all, his career is centered on developing technology that improves pavement conditions.
The Ohio University researcher and civil engineering associate professor was facing a fast-approaching deadline to prove his novel asphalt testing device was worthy of startup funding from the state of Ohio when he turned to Integrated Test & Measurement (ITM) for help.
The preeminent researcher had a challenge for Chase Petzinger, ITM software engineer. His scratch-built device — essentially an extreme oven/freezer combo that heats or freezes pucks of asphalt material to force expansion or contraction — needed complex hardware and a custom software solution to control signals from the device and ultimately record asphalt cracking data.
“I was extremely happy and impressed with ITM’s technical skills,” said Kim. “I was on a very tight schedule to finish the project in time, and they were very flexible and accommodating to my needs.”
The job required ITM’s team to develop software to record data from National Instruments hardware as well as control and monitor a custom built Watlow Programmable Logic Controller. In addition, the team had to design and build an enclosure that held all the data acquisition equipment and did all the power-cable management signal conditioning.
“So he had the oven shipped to us, and then he showed up with a big box of all the stuff that he had brought,” recalls Petzinger. “He set it down and said, ‘Okay, make this work.’”
Petzinger explained that he was able to customize the software application using LabVIEW to both collect the data from the sensors inside the oven as well as directly communicate with the device to control start and stop functions as well as the temperature inside.
“I think there were about 50,000 rows in this Excel document of different commands and ways that I could talk to the device,” said Petzinger. “I had to figure out how to use that information and then start from scratch writing a program that would send the commands that the oven could actually interpret.”
Petzinger considers these types of automation and data logging applications a melding of both science and art.
“We were able to create an application to communicate with a unique piece of hardware that we had never seen before,” he said. “if you have your own proprietary oven or switch or machine or something, we’ve worked with unique applications before, and we can do it again.”
Thanks to ITM, Kim not only was able to present his device to the Ohio Department of Development, but it outperformed even his own expectations.
“We wanted to demonstrate this testing device is indeed able to predict low-temperature performance,” he said. “We ran the test with the device that ITM made, and we had one of the best correlations I’ve seen in an asphalt pavement study.” Kim says ITM helped him prove that his device can predict which mixtures of asphalt will crack more accurately than existing tests. And, importantly, it will yield results in a single day where traditional asphalt studies take a week or longer. Next up in his effort to commercialize the unit, Kim intends to publish the results of his work in industry publications, and he’s already seeking a patent.
If the COVID-19 pandemic has proven anything, it is that we live in a business climate where efficiency and accuracy have never been more important. In other words, none of us can afford to make costly mistakes.
With that in mind, I’d like to share some tips for you to consider when it comes to this important question: How Do You Estimate Test Engineering Services Costs?
For engineers, testing engineers and managers who find themselves estimating jobs, getting this step right will prove crucial not only to the success of your projects and bottom line, but also to the trust you build with your clients.
Define the project scope of work
The most important requirement is to properly define the project scope of work. This will not only help you determine the necessary hardware, software, and resources required, but it will also help you identify the customer’s expectations and project deliverables. Properly defining the scope of work will help eliminate or minimize overall project time, as it will prevent delays both during the preparation phase and testing phases. Defining the scope of work will require a deep-dive discussion with your client to fully understand their challenges and goals. Remember not to leave vague language in your proposals. In other words, be sure to define who is responsible to provide all that will be needed to fulfill the project. Without a clear definition of the requirements and deliverables, it leaves a lot open for misinterpretation and expectations.
Materials costs are key
With a properly defined scope, we next must determine what, if any, materials we need to procure. These include sensors, DAQ hardware and other installation supplies. Don’t forget to include the amount of time that will be required to prepare all the materials and hardware. Think through such things as what it will take to package the DAQ hardware for any special environmental requirements. Also, be sure to consider the time it will take you to set up the software configuration file and test all the hardware and sensors prior to deployment.
Onsite costs are relative
We also need to consider the onsite testing requirements and location specifics. Costs can mount quickly to cover general travel and living expenses, particularly when the job will take your team to remote places for extended periods of time. You need to think about daily commutes to and from the facility as well as the cost variance for different geographic locations. Flights, vehicles, hotels and meals are crucial to estimate as accurately as possible, and that’s going to take extra research on your part. Keep in mind that travel costs are NOT one-size-fits-all.
Build in the value of analysis
Some projects require analysis support and some do not. It all depends on the customers’ resources and requirements. We serve customers by providing raw data files and allow them to perform their own analysis, but we also have experience providing a complete turnkey solution including data analysis. This requirement obviously needs to be defined up front in order to accurately estimate the opportunity.
Hidden costs are crucial
You need to consider everything when estimating a project, and this commonly involves “access to the instrumentation areas” for our projects. We typically work on large, complex equipment that sometimes require additional tools and resources to access the sensor locations. This could include manlifts, scissor lifts, cranes, rope access and scaffolding. Since the equipment is quite large, you need to think about the amount of signal cable required and evaluate that against deploying a network of DAQ chassis which may be a cheaper solution than routing all sensors back to a single DAQ system. It will also be key to build in language and costs in your estimates to address unforeseen delays. For example, include factors that lie outside of your team’s control — resources not being available, no access to equipment, or even poorly performing equipment that will not allow your team to record good data.
All sensors and gauges are NOT created equally
Sensor installation can vary from a couple minutes to a couple hours depending on the application. The same is true of strain gauges. Depending on the testing environment, strain gauges can be installed quickly or become an arduous task. Some applications involve very high temperature and moisture concerns and may also need to survive for long periods of time, which may require a more robust epoxy that requires a heat cure before data can be recorded from the strain gauges. Some applications involve no environmental concern and are only needed for a very short duration. In these cases, the gauges can be installed quickly after surface prep using an industrial type fast curing epoxy. Similarly, some applications may benefit from using weldable gauges that can simply be tack welded to the specimen. This eliminates any challenges and reduces installation time by using special epoxies. These are typically much more expensive, so you must evaluate the economics of this option. In either case, the surface must be properly prepped (ground, sanded, polished) to the base material to ensure a good bond to the test piece.
Consider variable labor and expense rates
Our labor rates vary by skill level. Senior engineering and programming labor, for example, costs more per hour than our regular engineering and programming labor. Similarly, sending a senior technician will cost more per hour than a technician. Finally, as is common, materials and expenses are estimated at cost plus 10%. Labor Rates Link
Ryan Welker is a 25-year veteran in engineering, procurement and project management. Ryan currently serves as a Vice President of Operations at Integrated Test and Measurement (ITM) in Milford, Ohio. In this role, he oversees the daily operations and monitors all phases of project fulfillment, including customer inquiries, proposal development, scheduling and manpower, employee training, on-site installations, customer follow-up, and support.
Choosing an accelerometer for rotating machinery vibration measurements can be a daunting task since there are so many options available. This blog outlines the characteristics you should consider when choosing a piezoelectric single axis accelerometer for general purpose vibration measurements and presents some accelerometers to consider.
Characteristics of a General Purpose Accelerometer
When measuring vibration on rotating equipment such as motors, pumps, and generators, the most common measurement location(s) are on the shaft bearing housing(s) at the shaft centerline. At this location, typical vibration levels perpendicular to the shaft are < 100 g and the frequency range of interest is < 5000 Hz. A general purpose single axis piezoelectric accelerometer with either a 10 mV/g or 100 mV/g sensitivity fits this criteria.
Other characteristics to consider are size, mounting options, cable connections, grounding, and cost. Several mounting options are available. They include magnetic bases, adhesive bases and stud mounts. The mounting option you choose affects the frequency range of your accelerometer measurements. The table below shows typical frequency limits for accelerometer mounting methods.
Mount Type
Typical Frequency Limit
Magnet
2,000 Hz
Adhesive
5,000 Hz
Stud
6,000 Hz
5 General Purpose Accelerometers
The table below shows some examples of stud mounted general purpose piezoelectric accelerometers. These accelerometers all have a female 10-32 coaxial / microdot connector. It is important to note that this is not a complete list of accelerometers and there are many options available from each manufacturer. I would encourage you to go to the websites linked in the table and see what’s available.
Last week our team successfully and safely installed another Boiler Monitoring System (BMS). This system, a Sootblower Fouling Detection (SFD) system, monitors structural and vibration sensors that quantify the boiler’s response to sootblower operations. The SFD system analyzes the boiler response data and outputs Key Performance Indicators (KPIs) such as fouling level, sootblower efficiency, and sootblower health to automated boiler cleaning systems.
This boiler uses over 50 sootblowers located at different elevations to clean soot build-up from boiler steam tubes. Since the vibration measurement locations are relatively far apart, the SFD system requires a distributed monitoring system consisting of several junction boxes that monitor and process data for groups of sensors. One team of engineers mounted the vibration sensors to the sootblowers and confirmed communication back to a local junction box containing the National Instruments condition monitoring hardware. The other team installed the junction box panels and terminated the sensor cables.
After all the sensor installations and terminations were completed, each sensor’s location and calibration were verified. While the sensor verification was being completed, one engineer worked with the mill IT department and the controls engineer to establish remote connection to the system and confirm communication with the mill’s automated cleaning system.
After commissioning the system and returning to our home base, our engineers are now monitoring the system through a VPN connection and assisting boiler operators with optimizing their cleaning process.
Over the years we have been tasked with identifying the root cause of machine structural failures. In many cases, we can determine the failure mode through strain and vibration testing, order analysis, modal analysis, and operating deflection shape analysis. What tests can you run when the damaging conditions are intermittent and not easily identified?
In these cases, we like to install a cellular networked temporary data acquisition (DAQ) system that can autonomously log vibration and strain data along with machine status data. We have deployed two types of DAQ systems to collect data remotely. An interactive system that includes an industrial PC running our iTestSystem software and National Instruments (NI) Compact DAQ hardware and a headless system that utilizes NI Compact RIO hardware. Our test engineers prefer using the interactive solution for troubleshooting because they can view real-time signal waveforms and collected data files, and then adjust the test parameters accordingly without having to reprogram the hardware.
Figure 1: Headless networked data acquisition system
When potentially damaging events are identified in the vibration and strain data collected by these systems, it is important to know the machine’s operating status. Collecting the machine status information is just as important as collecting the structural data. Many machines transmit these operating variables and operating stages over their network/bus. Recently we have recorded process data from Allen Bradley Control Logix PLCs via Ethernet/IP, mining machine data from a Siemens controller via proprietary TCP/IP protocol, boiler condition data from a DCS via Modbus TCP, machine pressures from PI historian via the UFL connector (TCP), and vehicle speeds and pressure via CAN. Fortunately, we were able to use and adapt LabVIEW communication protocol tools to build applications and addons that allow this network tag data to be collected along with structural data.
Figure 2: Modbus to Shared Variable Tool
After the data collection phase, our engineers perform statistical analysis on the sensor and status channels in all data files and aggregate the results into a database for searchability. To identify the root cause probabilities, you can process the channel statistics data using your favorite correlation algorithm or application. The image below shows an example data set containing related sensor data that was processed using a LabVIEW correlation test tool.
Figure 3: Correlation Test Example vi
Contact Information: For more information about our remote data acquisition service, our LabVIEW development service, or iTestSystem contact:
Mark Yeager – Integrated Test & Measurement (ITM), LLC. Email: mark.yeager@itestsystem.com or Phone: 1.844.TestSys
Image1: Shaft torque strain gauge installation example for field testing
Our engineers and technicians have epoxied, soldered and spot welded strain gauges for applications ranging from high temperature exhaust systems to miniature load cell measurements. Every application requires a unique understanding of the strain measurement requirements including installation environment.
If the strain gauge installation is to survive in the field you must plan for the conditions it will undergo. Three important variables that you should account for are temperature range, liquid exposure, and potential impact forces. These variables determine the type of strain gauge, epoxy, solder, wiring, coating, and impact/wear protection to use in the application. The table below shows which variables affect your installation choices.
Gauge
Epoxy
Solder
Wiring
Coating
Covering
Temperature
Liquid Exposure
Impact Forces
Table1: Strain gauge installation variables
For more information about ITM’s strain gauging services contact Ryan Welker at email: ryan.welker@itestsystem.com or phone: 1.844.837.8797 x702
https://itestsystem.com/wp-content/uploads/2019/09/Shaft-Torque1200x628.png6281200Ryan Welkerhttps://itestsystem.com/wp-content/uploads/2020/05/itmlogo_Horizontal_3x1.pngRyan Welker2019-09-13 18:01:532023-08-03 00:43:20Strain Gauge Installations for Field Testing
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