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Excitation Voltage 101

Excitation is an electrical signal. The excitation voltage is represented by the volts direct current (VDC). The direct current flows in one direction only. Alternating current (AC) changes direction at times.

Load cell excitation provides a voltage to generate an output signal, sometimes referred to as ‘powering’ the load cell. An output signal from a load cell is typically minimal, so an excitation voltage is needed to power the load cell and ensure the output signal is accurate. The magnitude of the output signal is proportional to the amount of force applied to the load cell. The greater the force, the greater the output signal.

Interface load cells contain proprietary strain gages applied to a Wheatstone bridge, essentially an electrical circuit that changes resistance when subjected to strain. The Wheatstone bridge is comprised of strain gages that are arranged in a specific configuration. When a load is applied to the load cell, the strain gages deform, and their resistance changes. This change in resistance causes the output voltage of the Wheatstone bridge to change.

Interface provides electrical performance data on all specifications represented as VDC MAX, when applicable.  The data for excitation voltage is listed under the electrical section of a transducer model’s specification datasheet, along with other factors, including rated output, bridge resistance, and zero balance.

Sensor Power and Excitation Tips

Load cell excitation is necessary to ensure the accuracy and reliability of load cell measurements.  Here are a few tips to consider regarding excitation and power signals when designing a force measurement system:

  • The output signal from a load cell is expressed in millivolt output per Volt (mv/V) of excitation at capacity.
  • The excitation voltage also affects the magnitude of the output signal. A higher excitation voltage will produce a higher output signal.
  • The output signal is directly affected by the input voltage. It’s essential to maintain a stable excitation voltage.
  • Interface load cells all contain a full bridge circuit. Each leg has a typical bridge resistance of 350 ohms, except for models like our 1500, which have 700 ohm legs.
  • The preferred excitation voltage is 10 VDC, which guarantees the closest match to the original calibration performed at Interface before it is shipped from our factory.
  • A DAQ system won’t always provide stable excitation voltage. Consider using a signal conditioner or DAQ with specific bridge inputs.

Why Load Cell Excitation Matters

Excitation matters in force measurement applications because it provides the power needed to operate the load cell and ensure an accurate output signal. The load cell cannot generate an output signal without excitation, and the force measurement will be inaccurate. In addition, it does influence accuracy, noise, and range.

Accuracy: The excitation voltage powers the load cell and ensures an accurate output signal.

Noise Reduction: The excitation voltage can help to reduce noise in the output signal.

Range: The excitation voltage can help extend the load cell’s measurement limit.

The excitation voltage should be applied to the load cell in a balanced manner. This means the excitation voltage should be applied to both sides of the load cell. The excitation voltage should be stable. This means that the voltage should not fluctuate or drift over time. The excitation voltage should be filtered. This means that any noise in the excitation voltage should be removed.

Excitation 101 in Force Measurement

The excitation voltage determines the sensitivity of the load cell. A higher excitation voltage will result in a more sensitive load cell, which means it can measure smaller forces.

The excitation voltage influences the frequency response of the load cell. A higher excitation voltage will result in a broader frequency response, meaning the load cell can track changes in force more accurately.

Linearity measures how accurately the load cell converts force into an electrical signal. A higher excitation voltage will result in a more linear load cell, meaning the output signal will be more proportional to the applied force.

The excitation voltage is well-regulated to reduce measurement errors. Variations in excitation voltage can cause a slight shift in zero balance and creep. This effect is most noticeable when the excitation voltage is first initiated. The solution is to allow the load cell to stabilize by operating it with a 10 VDC excitation for the time required for the gage temperatures to reach equilibrium. The effects of excitation voltage variation are typically not seen by users except when the voltage is first applied to the cell.

For tips like this, please consult Interface’s Load Cell Field Guide. We also detail remote sensing of excitation and temperature. Download your copy for free here.

It is essential to carefully select the excitation voltage for a load cell application to ensure that it can provide accurate and reliable measurements.

How Load Cells Are Transforming the Construction Industry

The construction industry is one the most universal, growing, and dangerous industries in the world. Interface force measurement solutions are used for all types of construction applications from bridge and high-rise building projects to foundation load tests and structural monitoring. Our sensors and instrumentation are used in crane and heavy lifting operations, material testing and equipment calibration.

Accuracy and quality of all measurement products used for design, testing, monitoring, and equipment evaluations is imperative in protecting the project’s assets and workers. One of the leading causes of construction accidents is overloading equipment. When equipment is overloaded, it can fail, leading to serious injuries. It is essential to utilize high accuracy load cell technologies to measure the amount of force being applied to construction equipment.

Interface force measurement solutions can help to prevent overloading accidents by using the measurement data to ensure that equipment is not being extended beyond its safety capabilities. Force measurement solutions can also be used to monitor the performance of equipment and identify potential problems before they lead to an accident.

Interface offers a wide variety of sensor solutions for construction equipment and material testing. Our load cells offer precise measurements of applied forces, furnishing essential data regarding the structural response under various load circumstances. This data plays a critical role in evaluating structural integrity, detecting potential vulnerabilities, and optimizing design to guarantee the safety and dependability of infrastructure.

Interface force measurement solutions can help to improve efficiency and productivity in the construction industry in all areas including engineering, testing and maintenance. By monitoring the performance of equipment, construction companies can identify areas where they can improve efficiency.

It is common to find Interface load cells, including load pins, load shackles, miniature and even jumbo load cells in use for various forms of construction projects, equipment and tools. These products, as well as torque transducers, instrumentation and wireless systems are frequently used in the testing and monitoring of the machinery, rigging and lifting devices, gear, and heavy duty vehicles that are used in various stages of building.

Interface provides various sensors for a range of construction use cases around the world, including:

  • Residential and commercial buildings
  • Infrastructure programs
  • Industrial construction
  • Material testing machines
  • Civil engineering projects
  • Mining and tunneling
  • Environmental remediation
  • Heavy equipment manufacturing
  • Vehicle OEMS
  • Cranes and lifting equipment


Construction is an ever-present and ever-growing industry estimated to reach nearly $13T in global spending with broad and diverse use of measurement solutions. From single dwelling construction tools to heavy machines used to move concrete slabs, measurement is fundamental in construction. Included below we have provided a few examples of how our sensors are being used in construction.

Construction Reach Stacker

A reach stacker is a vehicle used in construction site to lift, move, and stack heavy containers. A force monitoring system was needed to ensure the safety of surrounding personnel, and if the reach stacker can lift heavy loads. Interface’s WTSLP Wireless Stainless Steel Load Pins were installed into the corners of the lifting mechanism of the reach stacker, where heavy loaded containers are lifted and moved. The force results were then wirelessly transmitted to both the WTS-BS-1-HS Wireless Handheld Display for Single Transmitters, or directly to the customer’s PC with the WTS-BS-6 Wireless Telemetry Dongle Base Station. Using this solution, the customer was able to monitor their reach stacker with Interface’s Wireless Telemetry System and ensure its ability to lift heavy loads on site.

Bridge Construction Wind Monitoring

Wind monitoring is a necessary operation during bridge constructions. Strong winds can destroy a bridge under construction since it is a work in progress with poor structural design. Monitoring these winds in real time is much more accurate than using predicted weather forecasts. Interface suggested installing the WTS-WSS Wireless Wind Speed Transmitter Module on the highest point of construction, such as a crane. Wind speed results were wirelessly transmitted to the customer’s PC through WTS-BS-4 Wireless Base Station with USB Interface in Industrial Enclosure. It was transmitted to the WTS-BS-1 Wireless Handheld Display for Unlimited Transmitters Data can be displayed, logged, and graphed with supplied Log100 software. Interface’s WTS-WSS Wireless Wind Speed Transmitter Module combined with Interface’s Wireless Telemetry System was perfect to monitor the wind speed in real-time during the bridge’s construction.

Metal Bending Force Material Testing for Construction

A construction material supplier wanted to know how much force it takes to bend different grades of steel metal used for building and infrastructure projects. They use their metal bending machine to create different metal hardware and wanted to record the amounts of force it takes to bend the metal used for their projects. Interface suggested using a wireless method, so cables do not interfere with the machine. The WTS 1200 Standard Precision LowProfile® Wireless Load Cell was attached to the head of the hydraulic operated steel bender. Results were wirelessly transmit to the customers PC through the WTS-BS-4 Wireless Base Station with USB Interface, where data can be displayed, logged, and graphed with supplied Log100 software. Using this solution, the customer was able to record the force results of his metal bending machine with Interface’s Wireless Telemetry System.

Interface is adept at providing solutions suited for use in construction projects, equipment and ongoing monitoring programs.  If you have questions about what products are suited for your specific project, equipment or testing programs, contact us. We are here to help.

ADDITIONAL RESOURCES

Force Measurement Solutions for the Construction Industry

Interface Solutions for Heavy Equipment

Gantry Crane Weighing

Lifting Heavy Objects

Rigging Engineers Choose Interface Measurement Solutions

Innovative Interface Lifting Solutions

Modernizing Infrastructure with Interface Sensor Technologies

Interface Solutions for Structural Testing

Why Civil Engineers Prefer Interface Products

Innovative Interface Load Pin Applications

 

 

Innovative Interface Load Pin Applications

A load pin, which often replaces a standard clevis or pivot pin, is a strain gage sensor that measures the force applied across the device. The strain gages are installed within a small bore through the center of the pin. Interface load pins have been used in a wide variety of projects across many industries.

Load pins are a simple, but highly powerful sensor that provides data collection for accurate and frequent measurement. The load pin can replace a bolt, clevis, sheave, and an equalizer pin, as well as other load-bearing components to measure tensile and compression forces.

Machined from high tensile stainless steel, Interface load pins are suitable for exposed situations including seawater. We offer standard sizes of load pins between 1.1K lbf to 3.3M lbf (500kgs to 1500 MT). We also offer wireless load pins. Interface load pins are custom manufactured to meet specific dimensional requirements for each application, as detailed in our Use Cases for Load Pins webinar.

The most commonly referenced applications for load pins are for overhead equipment like cranes and lifts. Through ingenuity of engineers and our customers, load pins are rapidly expanding in popularity for infrastructure, aerospace, maritime, agriculture, and industrial use cases. The load pins of today are used to test and measure force, load, and weight in a much larger variety of applications. They are also growing in demands due to their wireless capabilities for both short and long distances. This includes uses not only for cranes and lifting devices, as well as construction equipment, industrial machines, nautical craft and equipment, aerospace structural environments, and civil engineering applications.

Infrastructure investment and projects around the world are on the rise. Investments in transportation ways like highways, waterways, bridges, mass transit, water supplies and power generation are frequently in demand of load pin solutions for use in all phases of the projects, from construction to maintenance and real-time monitoring.  Some of these examples are highlighted in Infrastructure Projects Rely on Interface.

Interface has a great deal of experience supplying ruggedized and standard use load pins for testing. Our load pins are highly demanded in the infrastructure industry not only due to the accuracy and reliability of our sensors, but also due to the fact that we offer a myriad of communication channels to offer both wired and wireless solutions. As requirements are made to repair and rebuild public infrastructure resilience, equity, and safety for all users are key criteria in design and build stages.  This is where Interface load pins are key to the solution, for durability, accuracy, quality, and ease-of-use.

Interface captured a few application examples of how our load pins are used for different types of projects, from maritime submersibles to monitoring new bridges during earth’s constant shifting.

AEROPSPACE:  Landing Gear Joint Testing

A global manufacturer in aerospace needs to test their new assembly and design by testing its landing gear joints. They want to ensure there are no flaws in the gear shock absorber design and can handle the applied forces when the craft lands from a flight. Interface’s WTSLP Wireless Stainless Steel Load Pins can be installed and replace the normal pin joints. The aircraft undergoes multiple drop tests at different heights, where the forces are applied on the load pins which then transmits the measurement data. The force results are transmitted wirelessly to the WTS-BS-4 USB Industrial Base Station and the WTS-BS-1-HA Handheld Digital Display for multiple transmitters. Read more about this load pin use case here.

MARITIME: Quick Release Hooks (QRH)

A customer wanted to test their quick release hook (QRH) system when their vessels are docked. They wanted to ensure the mooring lines are secured, but also, the quick release hooks were able to be easily and safely released. Interface’s WTSLP Stainless Steel Load Pin was installed into the quick release hook, where forces from the mooring lines can be measured and displayed when paired with the WTS-BS-4 USB Industrial Base Station. The load tension forces were displayed in real-time on the customer’s PC or laptop. The WTS-RM1 Wireless Relay Output Receiver Module alarm could also be triggered for the customer when maximum safety work load capacities have been reached or are overloaded. Using this solution, the customer was able to determine if their quick release hooks worked effectively within the safe working limit specifications, and was aware of any potential overload situations. Read more here.

INFRASTRUCTURE: Bridge Seismic Force Monitoring

A customer wanted to monitor seismic activity that occurs to a bridge by using force sensors and then continuously monitoring bridge forces before, during and after earthquakes occur. The customer preferred a wireless solution so they would not need to run long cables on the bridge. Interface helped to develop its LP Load Pin, which were custom made to fit their needs along Interface Inc. WTS Wireless Telemetry System continuous force monitoring was able to take place without long cables. Using this solution, the customer was able to monitor continuous loads, log information to the cloud and review information. Read about this solution here.

AGRICULTURE: Tractor Linkage Draft Control

A farming operation needs to measure the forces applied on their tractor’s draft control, between the tractor and any linked on attachments. Measuring the force helps the farmer sense any strains on the hitch of the tractor, and will be needed in order to apply any specific settings to the draft control when the tractor encounters rough terrain.  Interface’s WTSLP Wireless Stainless Steel Load Pin is a wireless load pin that can be installed directly in the hitch, replacing the normal shear pin of the tractor. Force results are transmitted wirelessly to the WTS-BS-4 USB Industrial Base Station, where they can view the results on a computer using Interface’s WTS toolkit. The customer can also view results on the WTS-BS-1-HS Handheld Display for Single Transmitters in real-time. Read more about this IoT Agriculture solution here.

 

INDUSTRIAL AUTOMATION: Crane Block Safety Check

A customer wanted a system to detect if their crane block can lift heavy loads securely, in order to keep working conditions and personnel safe. If lifting capacities are exceeded, the customer wanted a system to alarm them in real-time. Interface’s WTSLP Wireless Stainless Steel Load Pin replaced the existing load bearing pin in the crane block in order to measure the force being applied by the heavy load. The data was transmitted and displayed through both the WTS-BS-4 USB Base Station (when paired with the customer’s supplied PC computer/Laptop) and the WTS-BS-1-HA Wireless Handheld for real-time results. The WTS-RM1 Wireless Relay Output Receiver Module could also trigger an alarm when maximum capacity has been reached. The WTSLP Wireless Stainless Steel Load Pin, combined with the WTS products, was able to measure and determine force applied the moment a heavy load is lifted. The results were transmitted wirelessly, and ensured the customer whether or not the crane block was safely operational during production.

Are load pins the right solution for your project? Contact our load pin application engineers to learn more.

ADDITIONAL RESOURCES

Load Pins, Tension Links, and Shackles

Uses Cases for Load Pins

Recap of Use Cases for Load Pins Webinar

Applications Catalog

Load Pins 101

LP-TL-Shackles-Brochure

Interface Explores Maritime Applications Near and Offshore

Land, air, and sea are all the places where Interface force measurement devices are used to test and confirm product designs and measure real-time functions of equipment. Interface has long been providing an array of sensor solutions for use in the maritime industry.

The solutions are diverse including hydrofoil watercraft testing, yacht rigging inspections, and safety weight monitoring on massive cranes used on shipping docks and offshore. Interface provides various load cells, load pins, tension links, load shackles, instrumentation, and wireless products for splash zone, offshore and underwater sites.

The reason we are a top choice for products in or around the water is because of our line of submersible and rugged load cells and sensors designed for underwater applications and use in harsh weather conditions. From rigs and docks to structural waterways and bridges, our load cells can survive through underwater submersions at different capacities, and still be able to relay reliable and accurate data to instrumentation and receivers at the surface level. Interface measurement technologies are helping customers regulate harsh maritime situations including underwater tension lines for commercial fishing, nearshore hoisting apparatus at shipyards, undersea energy exploration, as well as storm and tsunami monitoring.

Specifically, our wireless load pins, load shackles, and tension links are ideal for marine applications. These products can be paired with our different wireless sensor transmitters, receivers, and handheld displays. Our Wireless Crosby Bow Load Shackles have been used for line tension testing and rigging. Our load shackles are inter-changeable with our WTSTL Wireless Tension Link Load Cell. The WTS-BS-4 Wireless Industrial USB Base Station is also a popular transmitter that gives outstanding coverage and can be easily paired with one of our handheld displays such as the WTS-BS-1-HA Wireless Handheld Display for Multiple Transmitters or the WTS-BS-1-HS Wireless Handheld for Single Transmitters.

Check out a few of our applications notes to see how these products can be used for testing in the maritime industry:

Hydrofoil Testing in a Wave Tank

Hydrofoil design for watercraft is a delicate balance between performance and complexity. Finding the right shape without using overly complex angles to achieve the desired amount of lift is crucial when designing a successful hydrofoil. Once an engineer’s concepts are ready for testing, using the best force measurement equipment is required to sense the subtle differences between hydrofoil designs. Lift and drag are the most important characteristics of a hydrofoil. The Interface Model 3A120 3-Axis Load Cell is needed to read these forces. The Fz senses lift and the Fx and Fy sense the drag. Using a model BSC4D-USB bridge amplifier increases the visibility of the load cells output signals. When using the load cell and bridge amplifier, the engineers can record the real-world lift and drag forces the hydrofoils are having on the watercraft. This data allows a more in-depth comparison of proposed hydrofoil designs to find the best model for the job. Learn more.

Mooring Line Tension Testing 

Due to the changing weather conditions, mooring cable lines undergo wear and tear. Users want to ensure all mooring lines for ships or vessels are securely docked at the same loading tension so that they do not risk the mooring lines to break or cause damage. Interface WTSLTL Lightweight Wireless Tension Link can be attached to each mooring cable in use. Results are sent to the customers through the WTS-BS-4 USB Industrial Base Station when connected to the customer’s supplied PC computer or laptop. Data can also be transmitted to the WTS-BS-1-HA Handheld Display for Multiple Transmitters, giving the customer the option to view multiple mooring cable line tensions. Using these Interface products, the customer was able to verify the tensions to multiple mooring cable lines. Thus, resulting in the security of their ship being safely docked on shore. Check out the app note here.

WTS Yacht Rigging Inspection

For a customer who wants to have a complete rigging inspection to make sure the mast, still lines, and all movable hoisting lines are functional and meet the proper specifications for sailing, Interface has the products to help. To test the tension of the forestay, shroud, and backstay cables, and the tension of the movable lines when sailing, Interface provided a WTSSHK-B Wireless Crosby™ Bow Load Shackle paired with the WTS-BS-1 Wireless Handheld Display for Unlimited Transmitters. This allows customers to switch and view between multiple shackles being tested during the inspection. The WTS-BS-4 USB Industrial Base Station can also be attached to the customer’s PC or laptop to display real time measurements from the shackles and log data. With this combination of technology, the customer was able to conduct both a running and standing rigging inspection of their ship or vessel and was able to determine if all lines were functional and met safety standards. Learn more here.

Dock Crane Safety and Capacity Verification

It is essential that heavy equipment used on the dock can verify that their crane is strong enough to safely lift a heavy load. For productivity and timing, it also is helpful to constantly measure and rate maximum load capacity. In these environments, a wireless solution is needed to avoid long cables, and to have a faster installation time. Using the WTSTL Lightweight Wireless Tension Link Load Cell, operators can measure the load’s maximum capacity. The WTS-RM1 Wireless Relay Output Receiver Modules also can trigger an alarm that can be set when the maximum capacity of weight and force. The data is transmitted and can be reviewed with the WTS-BS-1-HS Wireless Handheld Display, or, on the customer’s receiving technology. Read more here.

As you can see, Interface has got Maritime covered with a wide variety of products suitable for submersion and the harsh weather that can be found at sea. In addition, if our off-the-shelf products don’t quite meet your use case, Interface’s custom solutions team will work alongside you to create the most effective and efficient solution based on your needs.

Load Pins 101

A load pin is a type of load cell that can replace bolts, clevis, sheave, and equalizer pins, as well as other load-bearing components to measure tensile and compression forces. Load pins are internally gauged with a bored center containing strain gauges, allowing them to convert force into an electrical signal for engineers to accurately collect data.

Most applications for load pins in the past have been for overhead equipment like cranes and lifts. Load pins have expanded in popularity and are now often used to test and measure force, load, and limitations in a much larger variety of applications. This includes uses not only for cranes and lifting devices, but also construction equipment, industrial machines, nautical craft and equipment, aerospace, and civil engineering applications. A primary system approach with structural applications is for safety and to prevent excesses in loading and lifting.

New model types with wireless and Bluetooth technology are also resulting in more use cases for these specialized force measurement solutions. This applies to both test and measurement as well as for installed OEM components within a larger structure or apparatus.

Top Load Pin Benefits

  • Easy to install new or retrofit
  • Robust construction
  • Replaces existing load bearing pins without any system modifications
  • Engineered to order designs available
  • Can be supplied with integral connector
  • Custom sizes and higher capacities available

Load pins come in many standard shapes and sizes, as well customization options to meet a specific design or use requirement. Interface provides these measuring devices, which often replace a bolt or pin, for safety and application monitoring. Some of our load pins are exclusively designed to meet the needs of applications in hazardous environments like the oil and gas industry, or marine industry where they’ll be submerged in water during testing and for continuous use.

The Interface Load Pins are machined from high tensile stainless steel and are suitable for exposed situations including seawater. We offer standard load pins with ratings between 1.1K lbf to 3.3M lbf (500kgs to 1500 MT). We also offer custom manufactured load pins suit applications from 100 kgs to 1500+ MT.

LP Stainless-Steel Load Pin – Great for lifting applications for both short and long distances. This product can be amplified with 5VDC, 10VDC or 4-20mA Outputs. It can also be made to meet ATEX requirements. Model LP Load pin is available in capacities up to 3,000,000 lbf (13.3 kN).

WTSLP Wireless Stainless-Steel Load Pin This advanced load can transmit wirelessly up to 600 (1,969 feet) meters in distance (clear line of sight) to a handheld display or USB base station.  The capacities range goes all the way up to 3,000,000 lbf (13.3 kN). The wireless option utilizes low power consumption for long battery life. It is configured and calibrated via PC using a base station and telemetry toolkit and compatible with Interface WTS Wireless products. The load pin is robust and uses a lightweight housing. It is environmentally sealed to IP67.

Load Pin Application

One of the largest scale applications of load pins we provided were used to measure force on a large bridge infrastructure project in the western U.S. The goal was to continuously monitor the standard force created by regular traffic, as well as the seismic force before, during, and after earthquakes. The monitoring sensors needed to be integrated into a dampener that would be attached to the structural tower.

The solution allows the company to monitor force from emitted data to cross-reference the standard traffic force with the seismic force to understand its effect on the bridge. Its purpose is to help with predictive maintenance and influence future bridge designs to better compensate for the forces of an earthquake or other natural disasters, which are common in this part of the world.

READ THE SEISMIC BRIDGE MONITORING APPLICATION NOTE HERE

READ THE INFRASTRUCTURE CASE STUDY HERE

The project required a custom product that could handle the inimitable and considerable force of a bridge under every scenario of distress. Engineers developed a custom load pin to handle the force of movement in the bridge in the event of an earthquake. This load pin was much larger than our standard version and is rated at 900,000 lbf. The large load pins were designed to be integrated into the dampener with wireless data acquisition modules connected to the load pins to allow for remote access to the data. With the integration of Interface’s custom load pins and data acquisition module, the customer was always able to continuously collect data for real-time evaluation. The sturdy construction of our load pins and 900,000 lbf rating allowed for readings during all degrees of seismic activity.

To learn more about our wide variety of load pins and there many applications, please contact our application specialists today.

Seismic Application for Interface Load Pins

The range of applications of force measurement is wide-ranging across many industries. You can find Interface Mini Load Cells are frequently used to measure minute forces in precision medical devices, while our jumbo precision load cells that are rated for 2,000,000 pounds of force (lbf) are used to measure the force of rocket thrust.

Interface recently completed another extraordinary force measurement solution for a large scale infrastructure project, the first of its kind for the 51-year-old company.  Engineering and solution experts created custom load pins to measure the seismic force on the Gerald Desmond Bridge. There are interesting details that give a perspective on how force is used to provide safe passages.

Sensors are essential in innovation, with a dependency on accuracy and reliability that impacts lives and ingenuity.

BACKGROUND

The Gerald Desmond Bridge, a bridge located in Long Beach, California, opened in 1968. It is a major commuting route for the region, and a major trade corridor carrying 15 percent of all containerized cargo imported to the United States. The bridge connects Terminal Island, the heart of the port complex, with the Long Beach Freeway as well as downtown Long Beach. In 2012, a large civil construction contractor was tasked with replacing the existing steel arch bridge with a new suspension bridge rising more than 200 feet over the water.

CHALLENGE

The contractors, an Interface customer, wanted to find a way to measure the force on the Gerald Desmond Bridge in the event of an earthquake. The goal was to continuously monitor the standard force created by regular traffic, as well as the seismic force before, during, and after earthquakes. The monitoring sensors needed to be integrated into a dampener that would be attached to the structural tower. The solution that would allow the company to monitor force from emitted data to cross-reference the standard traffic force with the seismic force to understand its effect on the bridge. Its purpose is to help with predictive maintenance and influence future bridge designs to better compensate for the forces of an earthquake or other natural disasters, which are common in this part of the world.

SOLUTION

Interface was engaged to create a unique infrastructure solution. It required a custom product that could handle the inimitable and considerable force of a bridge under every scenario of distress. Interface engineers developed a custom load pin to handle the force of movement in the bridge in the event of an earthquake. The load pin is much larger than our standard version and is rated at 900,000 lbf. The large load pins are designed to be integrated into the dampener with data acquisition modules connected to the load pins.

RESULTS

With the integration of Interface’s custom load pins and data acquisition module collect data at all times. The sturdy construction of our load pins and 900,000 lbf rating allow for readings during all degrees of seismic activity. We are also able to ensure product durability because the failure rating of the custom load pins is maxed out to 2.7 million lbf. An added benefit of this project was the Interface R&D efforts applied to create future data acquisition modules like this that utilize wireless technology.

Source: Ted Larson, VP of Product Development

READ COMPLETE CASE STUDY HERE

Interface Case Study for Bridge Project

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