ITM Helps Pave Way to Better Asphalt Testing

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.’”

Specific sensors and fixtures included GT1000RA LVDT Sensors, NTC-6000 signal conditioners, RDP S7AC signal conditioners and custom-built stainless-steel fixtures. In addition, the data acquisition process required employing a NI cDAQ-9174 Chassis, NI-9216 RTD modules as well as an NI-9209 Voltage Module.

Asphalt Crack Prediction Control Panel

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 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.

For more information about this project or other LabVIEW development projects contact Mark Yeager @ (844) 837-8797 x701

iTestSystem Tip: Sensor Auto-zero Utility Update

Our iTestSystem customers who routinely acquire data with high channel counts and data from full-bridge transducers recently requested that we update the sensor auto-zero utility to improve test setup efficiency.   In the latest version of iTestSystem, we updated the sensor auto-zero utility to include all channels that use the From Custom Scale option.  This update enables users to quickly adjust selected channel offsets with only a few mouse clicks.

One of our test engineers recently used this feature to test and calibrate a new load cell design for measuring loads in a manufacturing process.  He was able to quickly calibrate and zero the strain gauges along with a calibrated load cell and a pressure transducer prior to testing and before each directional test. The offset values are included in the calibration data files for traceability.

Contact Information: For more information about this update or iTestSystem contact:

Chase Petzinger – Integrated Test & Measurement (ITM), LLC. Email: or Phone: 1.844.TestSys

Troubleshooting Machine Failures Caused by Intermittent Damaging Events

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: or Phone: 1.844.TestSys

Recent News:  Ohio University Asphalt Cracking Prediction System Project

ITM adds NI-9253 Compatibility to iTestSystem

This week we added another module to the iTestSystem compatibility list.  One of our iTestSystem users recently needed to collect data from thirty-two (32), 4 to 20 mA current sensors along with their vibration measurements.  National Instruments (NI) recently introduced a new C-Series current module, the NI-9253, that was a perfect fit for this application.

The NI-9253 module has eight (8) simultaneous sampled (50kHz max), +-20 mA, 24-bit input channels.  It has several diagnostic features to ensure your system is operating nominally at all times with open channel detection, power supply detection, and configurable thresholds. The NI-9253 has eight LEDs that indicate the status of each channel and the power supply so a user can easily determine the system’s status in the field.  The NI-9253 also features a number of programmable hardware filters (Butterworth and comb) to reduce signal noise.

Click Here for more information about iTestSystem.

For advice about using the NI-9253 versus other current modules in iTestSystem monitoring applications or with custom cRIO RT and FPGA control applications contact Mark Yeager or Chase Petzinger.

Roving Accelerometer Impact Tests with iTestSystem

3D Animator: Bike Frame Twist Vibration Mode at 26.2 Hz

In order to prevent or troubleshoot structural vibration problems, it is important to characterize a structure’s dynamic behavior using both experimental and Finite Element Analysis (FEA) technologies.  One method used to identify a structure’s vibration modes is to perform a roving accelerometer or roving hammer impact test.  In an impact test, engineers measure the response of a structure from an impulse delivered by a calibrated hammer using tri-axial accelerometers.

FRF View: Bike Frame Point 9 Coherence & Magnitude

Managing impact tests on large structures can be tedious and cost prohibitive, since they require collecting accelerometer responses at hundreds of locations to resolve the vibration motion.  Not only do test engineers need to keep track of the locations, they also need to keep track of the orientation that an accelerometer is positioned.

Our test engineers have found that the most efficient and cost effective solution for collecting impact data is to use a National Instruments (NI) cDAQ chassis with either NI-9234, NI-9232, NI-9231 or NI-9230 IEPE modules along with a calibrated impulse hammer and between 3 – 9 tri-axial accelerometers. To collect, manage, and visualize the modal data, our LabVIEW software engineers developed the Impact Test DAQ, FRF Viewer, and 3D Animator applications for our iTestSystem software platform. These applications incorporate tools that our test engineers need to manage and validate the quality of their modal data while in the field.

For more information about impact tests, modal analysis, our iTestSystem Impact Test applications, or to schedule a modal test contact Mark Yeager or Ryan Welker.

Click Here to download iTestSystem

ITM adds FieldDAQ Sound & Vibration Module compatibility to iTestSystem

The FieldDAQ™ FD-11634 sound and vibration input module from National Instruments (NI) can now be used with the latest version of iTestSystem.  The FD-11634 is similar to the NI-9234, NI-9232, NI-9231, and NI-9230 cDAQ dynamic input modules and can be used with IEPE type sensors such as accelerometers and microphones.  Like the other FieldDAQ™ modules, this module is IP65/IP67 dust and water resistant with an operating temperature range of  -40 °C to 85 °C.  Our test engineers would use these modules for collecting vibration data on mining and construction equipment, vibration data on rotating machinery within manufacturing facilities and test cells, and acoustic data for measuring equipment noise emissions.

The FieldDAQ™ FD-11634 module has 8 simultaneous sampled, ±1V or ±10 V, 24-bit differential input channels with AC/DC coupling. It has a maximum sample rate of 102.4kS/s and features built in anti-aliasing filters that automatically adjust to the sampling rate.

For advice about using the FieldDAQ™ FD-11634 sound and vibration modules in iTestSystem monitoring applications or with custom cRIO RT and FPGA control applications contact Mark Yeager or Chase Petzinger.

Click Here to view a video showing one of our test engineer collecting data from a submerged FieldDAQ™ module with iTestSystem.

Click Here for more information about iTestSystem.

Strain Gauge Shunt Equivalent Calculations in iTestSystem

When making strain measurements it is important to perform a shunt calibration both before and after the actual measurements are acquired.  Shunt calibrations ensure accurate strain measurements by adjusting the sensitivity or gain of the data acquisition equipment to compensate for leadwire resistance and other scaling errors.

iTestSystem takes advantage of the shunt calibration circuits included in the National Instruments (NI) cDAQ strain modules.  The NI-9235, NI-9236, and NI-9237 strain modules contain an internal shunt resistor that when switched on “shunts” across one leg of the strain circuit’s wheatstone bridge.  When active, the shunt resistor offsets the strain measurement by a constant strain which is calculated using the equivalent shunt calculation.  The equivalent strain/shunt value is dependent on the strain gauge configuration, gauge resistance, shunt resistance, gauge factor, and material properties.

In the latest version of iTestSystem, we added a built-in strain gauge shunt equivalent calculator that can be accessed from the strain configuration page.  This calculator has allowed us to speed up the calibration process and eliminate hand calculation errors.

For a free trial of iTestSystem and the equivalent shunt calculation tool, contact

ITM Live Demo Series: Configuring Ethernet Chassis in NI Max

The latest video in the ITM Live Demo series shows users how to configure an Ethernet/Network cDAQ or FieldDAQ chassis with NI Measurement & Automation Explorer (NI Max).

One of the most common questions we get from iTestSystem users; How do I configure my network/ethernet cDAQ or FieldDAQ chassis?  In this video, Chase Petzinger demonstrates how to change a cDAQ’s network settings.

If you’re interested in learning more about iTestSystem and networked cDAQ chassis measurements, feel free to contact one of our test specialists by e-mail at or phone at (844) 837-8797.

ITM adds NI-9242 compatibility to iTestSystem


The NI-9242 single ended voltage input module can now be used with the latest version of iTestSystem (16.1). The NI-9242 C-Series module features three (3) voltage inputs plus one (1) neutral input, 24-bit resolution, 250V rms L-N, 400V rms L-L, and 50 kS/s/ch. The measurement range (250V rms L-N or 400V rms L-L) makes it ideal for embedded 120V rms and 240V rms grid measurement applications such as phasor measurements, power metering, power quality monitoring, industrial machinery, motor testing, and transient or harmonic analysis with high-speed (50kHz) simultaneous sampling.

Click Here for more information about iTestSystem.

For advice about using the NI-9242 in stand-alone power quality applications or cRIO power monitoring applications contact Mark Yeager.

ITM adds NI-9246 compatibility to iTestSystem


In the latest release of iTestSystem (v 16.1), we are adding the NI-9246 current input module to the compatibility list. The NI-9246 features 3, 22 Arms continuous current inputs, 24-bit resolution, and 50 kS/s/ch in the C Series form factor. The measurement range (22 Arms ) makes it ideal for three phase current measurements from 1A and 5A current transformers. These types of measurements are used in embedded industrial, power generation applications like power quality monitoring and machine condition monitoring.

Click Here for more information about iTestSystem.

For advice about using the NI-9246 in stand-alone power quality applications or cRIO power monitoring applications contact Mark Yeager