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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.

Aerospace and Defense Industry Solutions

Among the many applications Interface products are used for across multiple markets, there may be none that require the highest levels of accuracy, quality and reliability as does the aerospace and defense industry.

By classification, aerospace largely comprises of those engaged in producing and servicing of commercial aircraft. The defense market is defined as those providing military weapons and systems designed to operate in the air, in the sea or on land.

The aerospace and defense industries are global markets that continue to expand their use of precision sensor technologies for advancing innovations in autonomous vehicles and flight systems, electric and hydrogen engines, as well additive manufacturing applications. Interface proudly serves the world’s largest manufacturers and suppliers in the aerospace industry by providing world-class force and torque measurement solutions for these types of requirements, as well as for their future inventions.

Over the past two years, the trends in the global commercial space ecosystem along with defense needs have created unique requirements that benefit from our five decades of being a premium provider for A&D equipment manufacturers and testing labs. We are able to meet these trending demands through our standard, engineered to order and completely custom force, torque and systems. These solutions are being utilized in testing of all types of vehicles, on the ground, in the water, and for flight.

A&D is a unique industry because of the complex needs of many applications. When we develop applications for other industries, we’re typically focused on solving a few specific challenges, whether it’s related to cost, safety, performance, environment, or other engineering specified design requirements. In aerospace and defense, every one of these factors needs to be addressed, as well as some special needs. Applications in the aerospace and defense industry cannot fail. If they do, it can put people, both military and civilians, in danger. That’s why force products in the defense industry need to be of the highest quality in all key factors.

Below are a few applications for force measurement in the defense industry. Each demonstrates the criticality of proper force testing, as well as the complexity of the projects Interface has been involved in.

SLS Tank Test

As outlined in NASA’s article on the SLS Tank Test, NASA’s goal was to push the very limits of a test version of the world’s largest rocket fuel tank. The project put incredible flight test strain on the tank to try and push it to its breaking point. After five hours of testing and more than 260% of the expected flight load, the tank finally buckled. Doing this helped engineers gather data on the tank to help intelligently optimize the final rocket ship.

In this application, load cells played the key role of collecting the flight force data. The extreme nature of the flight tests meant that the load cells needed to be incredibly durable and provide accurate data all the way through the breaking point.

Structural Testing

For the many hundreds of thousands of commercial and military vehicles on the market, especially those that fly, there are numerous force tests involved to validate a design and ensure they’re safe and of the highest quality to move into production. Load cells and torque transducers are used across a wide variety of vehicles for structural testing. The torque of the helicopter rotor is measured and validated using a torque transducer, or the wings and hull of an airplane are put through wind tunnels and other stress tests with load cells installed to collect data. All of these force applications are critical to ensuring that these vehicles can last beyond their intended breaking point and offer complete peace of mind to operators and passengers. There are a million different things that a military pilot is thinking about – the structural integrity of his or her aircraft should never be one of them.

Custom Sensors

Another area that has grown in recent years as technology pushes the aerospace and defense market forward is custom sensors. Test has gotten more sophisticated as the move to big data becomes more prevalent, and Interface has addressed this by working directly with customers to develop custom sensors that address unique challenges.

One of the biggest areas where we have seen a growing need for custom sensors is on test stands in thrust application. Test stands are often used in field testing on rocket or plane engines. In certain field applications, the test stand is outfitted with numerous load cells that must be custom designed with features like weatherization, multiple bridges, very-high precision, and more. The reason for this is because the cost of a thrust test in fuel alone can be incredibly high. You usually only get one shot at a successful thrust test. If there are any issues with the sensor, it’s going to be costly.

Interface has deep experience developing custom sensors for our aerospace and defense partners. We understand their needs and work closely with their engineering team to ensure they get it right the first time. If you’re interested in learning more about Interface and our solutions for the aerospace and defense industry, please visit us at www.interfaceforce.com/solutions/aerospace.

For additional references, check out our A&D related case studies and application notes:

Launching Into Orbit with Interface

Force Measurement for Space Travel

Interface’s Crucial Role in Vehicle and Urban Mobility Markets

Aircraft Wing Fatigue Test

Rocket Structural Test

Wind Tunnel Testing

Contributor: Elliot Speidell, Interface Regional Sales Director

Understanding Uncertainty in Load Cell Calibration

In force measurement testing, accuracy is the most critical factor in ensuring the data you collect can help to identify challenges, failures and opportunities in the product design and development cycle. Here at Interface, we have mastered the art of load cell accuracy by employing a vertically integrated manufacturing process that allows us to control the development of our products most critical components.

Even the most high-end manufactured load cells and finely tuned components endure accuracy degradation over continued use. Therefore, we have also invested in equipment and talent with deep expertise in load cell recalibration, as well as offering gold and platinum standard calibration systems to customers. Recalibration is recommended on an annual basis, or of course, whenever our customers feel they need to confirm they are getting the right data out of their load cells.

One of the key factors of calibration and recalibration is understanding how to estimate practical uncertainty in load cell calibration. Measurement uncertainty is defined as an estimate of the range of measured values within which the true value lies or, alternatively, the degree of doubt about a measured value. In every application, there will be an uncertainty requirement on the force measurement. The equipment used to make the measurement must be traceable to a realization of the SI unit of force (the newton) within this required uncertainty.

Each application is different in terms of its uncertainty requirement. For instance, an application testing force in the aerospace and defense or medical sector will include a much more stringent uncertainty requirement than something like a commercial scale used to measure someone’s weight or food. It is critical to understand the uncertainty requirement on the application to ensure the force measurement device used is calibrated to handle the project.

How does one go about estimating uncertainty in load cell calibration? The first thing to understand is the GUM, a guide to the expression of uncertainty in measurement. This guide establishes general rules for evaluating and expressing uncertainty in measurement that are intended to be applicable to a broad spectrum of measurements.

Next, we have included a list of different considerations, as we measure uncertainty here at Interface. These factors will help guide you as you determine uncertainty for yourself. This list includes:

  1. Determine what parameter is to be measured and the units of measure.
  2. Identify the components of the calibration process and the accompanying sources of error.
  3. Write an expression for the uncertainty of each source of error.
  4. Determine the probability distribution for each source of error.
  5. Calculate a standard uncertainty for each source of error for the range or value of interest.
  6. Construct an uncertainty budget that lists all the components and their standard uncertainty calculations
  7. Combine the standard uncertainty calculations and apply a coverage factor to obtain the final expanded uncertainty.

It is also important to consider the different methods of load cell calibration. There are three different methods, and each has an approximate feasible expanded uncertainty. The different calibration methods include:

  • Direct dead weight – this method is the best for accuracy at 0.005% uncertainty, but it is slow, and the equipment is space inefficient.
  • Leveraged dead weight – middle of the road for accuracy at 0.01% uncertainty, and slow and space inefficient.
  • Hydraulic force generation comparison – this method has reasonable accuracy at 0.04% uncertainty and is also the fastest and most space-efficient option.

The final point is the sources of error in calibration. Error is defined as the difference between the measured value and the true value. There is a long list of different factors that can cause error and increase uncertainty. These factors may include drift, creep, misalignment, or environmental factors such as temperature. To compensate for this, it is important to understand the various formulas that can be used to find the true value based on the given measurement and the various factors for error.

To learn more about uncertainty and the different ways users can address uncertainty and overcome it, please give us a call at 480-948-5555, or visit our website to contact our Application Engineers.

Contributor:  LaVar Clegg, Interface

Source: NCLSI Measurement Training Summit 2014

Testing for Commercial Drones and Parcel Delivery

Drone parcel delivery, and the use of drones in general, has expanded rapidly throughout the world. A technology that was once relegated to science fiction and imagination is becoming a real-world asset and making a huge impact on many commercial use applications in military and defense, consumer goods, logistics and inventory management, industrial automation, construction, security, agriculture, healthcare, imaging and surveying, as well as shipping and fulfillment.

To give you an idea of the impact of drones, take a look at recent numbers published by the FAA on registered drones in the U.S.:

  • 1,710,159 Drones Registered
  • 495,909 Commercial Drones Registered
  • 1,210,751 Recreational Drones Registered
  • 195,346 Remote Pilots Certified

There is a significant role for test and measurement as well as embedded sensors in this growing industry, which is expected to reach of $6B in size in the next few years. Load cells play a huge part in the design and development of this specialized aircraft technology and ongoing monitoring while in flight. Drones are classified as unmanned aerial vehicles. Basically, an aircraft without a human pilot. Successful operation of a UAV is dependent on a system, including the vehicle, a ground-based controller, and communications components, all of which must pass rigorous performance testing standards and constant data feedback.

The knowledge and tools we apply to test and measure airplanes and spacecraft performance can be transferred at a smaller scale to drones. Drone OEMs need to collect data points on thrust and velocity in test, and they also need to collect real-time sensor data on drones in-use. In fact, a large variety of sensor types are used for drone applications, including: force sensors, gyroscopes, barometers, and accelerometers.

Most recreational drones have passed significant testing during the engineering and design phase to ensure safety for anyone on the ground. Early applications and adoption sparked immediate regulation and safety requirements. We are now seeing the fastest expansion of this technology into commercial use. The future of drone technology for wide-scale business use has several of the world’s largest companies engaged in expansive development and deployment in use of UAVs for package delivery, including Alphabet (Google), Amazon, UPS, CVS and Walmart.

Commercial applications require substantially more rigorous testing in all use cases, in particular for transportation of objects. Most developed countries have defined commercial use requirements and regulations, such as the FAA in the U.S. Not only is the safety of those on the ground important critical, so is protecting the value of the goods in transport.

In demonstrating how force measurement solutions are used with drone technology, Interface created animated application note showcasing how a force solution is necessary for real-time monitoring of drones used in the shipping and fulfillment markets. Testing beyond flight, there is a level of complexity present when you introduce the weight of a package to a drone.

DRONE TESTING USE CASE

Customer Challenge:

A customer approached Interface to deliver a force solution capable of weighing a “payload” and using that data in real-time to tell the propeller motors to compensate for weight shifting or uneven weight distribution. The purpose of the force solution was to help the drone lift the payload and fly normally to reach its destination.

Interface Force Measurement Solution:

To solve this challenge, Interface supplied four WMC Sealed Stainless Steel Miniature Load Cells, which were used to measure the weight of the payload and detect weight shifting and distribution in flight. As shifting and uneven distribution occurred, the load cells send a signal to the necessary propeller motors to compensate.

How it Works:

The four miniature load cells are connected independently to each of the four landing gear legs. The load cells are then connected to the drone’s processor, which allows the load cell to communicate the weight of the payload and store the information. As the drone flies and weight shifts, the load cell can then relay the information to the processor in real-time so that the individual motors increase in RPM to balance the shifting weight.

Subscribe to Interface’s YouTube Channel to see our latest animated application notes. This new series of animated application notes give viewers a better sense of how force measurement products are applied to real-world challenges to collect and analyze data. So far, we have produced three animated application notes, which we have linked below:

 

Interface Forms Partnership with Manufacturers’ Representative Hill and Company

In a move that expands Interface’s ability and expertise in serving our customers across a wide range of industries in the Midwest, Interface today announced a new partnership with manufacturers’ representative Hill and Company.

Hill and Company brings more than 85 years of experience and expertise working with OEMs and other customers in the HVAC, computer, agriculture, defense, aircraft and electronic equipment industries to help solve technology-related challenges.

Based in Kansas City, Missouri with an expansive Midwest presence, the company will provide sales support for Interface, the leader in force measurement solutions, across Missouri, Kansas, Iowa, Nebraska and Southern Illinois.

“Interface has long been known as a premium provider of the most accurate and reliable force measurement equipment in the industry,” said Ed Hill, president, Hill and Company. “We’re thrilled to have the opportunity to sell Interface products across the many industries we represent. Our history in the Midwest serving a wide variety of manufacturing operations, combined with our ability to bridge the gap between customer needs and products, will ensure our partnership with Interface remains long and mutually beneficial.”

Hill and Company was founded in 1933 by Nathan Hill. The product lines the company sells includes a wide range of electronic and software solutions, including electronic controls, circuit boards, thermostats, flash storage, motors, transformers, power supplies, relays, and wireless software. Its lineup will now include more than 36,000 force measurement products, services and custom solutions from Interface.

Hill and Company will focus its efforts for Interface on leveraging new and existing relationships with OEMs and other customers across the Midwest to offer force measurement solutions that meet their evolving needs for test and measurement, sensor technologies and components.

Hill and Company has built its reputation with long-standing in the region on consistency, reliability and a wealth of knowledge related to technology solutions to addresses their most complex challenges. Interface welcomes Hill and Company to our tightly-knit global sales network, and look forward to working with them and their customers to deliver value, experience and expertise in the form of highly reliable and accurate force measurement solutions.

To locate a representative or distributor of Interface products, click here.

 

Interface is a Critical Solutions Provider for OEMs

The hardware industry is rapidly making its way into taking advantage of the Industry 4.0 and Big Data eras. The idea that data insight can cut costs, increase efficiency and reduce downtime is spreading like wildfire throughout major OEMs (original equipment manufacturers) across the world. These organizations are adding more and more sensors and other data collection devices to their products to receive deeper analytics on the health and efficiency of various in-action processes.

One of the most important tools in this mix of data tracking and collecting devices are force measurement sensors. Load cells and torque transducers are being added to products across industries to not only optimize individual product processes, but also to ensure that the product remains in proper working conditions.

As an example, the aerospace industry is putting force sensors all over airplane components. Everything from landing gear to the wings may include a sensor. These force sensors can then be used to constantly collect data on the well-being of these components. If landing gear needs to be fixed or adjusted, you don’t want to find that out while your 30,000 feet in the year. You want data that helps you track performance and potential degradation over time so you can solve problems before it puts lives at risk.

To serve OEMs in automotive, aerospace, robotics, medical and consumer product industries, force measurement companies like Interface must be able to manufacture sensors in high volumes and at affordable price points. Load cells and torque transducers used in test and measurement can be reused over and over, so the demand for higher volumes is lower. However, when the sensor is integrated into the final product, force measurements manufacturers need to be able to deliver a high enough volume to meet the OEM’s demand for production of the specific product the sensor will be integrated into for continuous use.

Interface holds a unique position in the OEM marketplace for custom sensor technologies. Our decades of success has allowed us to make critical investments towards streamlining our own production and manufacturing of industry-leading components to serve OEM customers. Over the last few years, we’ve implemented better, more efficient processes and have added automation to improve consistency, repeatability and time to market. This also benefits our customers by lowering costs for large scale, continuous production to meet the growing demands and use cases in the OEM market.

A huge benefit is that Interface controls the design and development of our load cells and torque transducers. We build everything from the strain gauges to the product packaging. This allows us to rapidly iterate and customize our designs to meet the needs of a wide range of OEM customers. Our engineers work hand-in-hand with our OEM partners to design the exact requirements into our sensor technology.

This is critical to being a top solutions provider serving OEMs because force measurement products must fit the design and specifications of the OEM application, as well as potentially removing unnecessary features to fit a certain price point for volume production. OEM applications can also be exposed to more extreme conditions in industries like aerospace, automotive or medical, so the sensor might need a specific material or treatment to withstand certain environments.

One of the essential benefits we provide our customers in the U.S. is the fact that our products are manufactured in country, and our engineering, sales and support staff is also local. This enables easier communication with our customers, as well as faster shipping times. When a customer needs to adjust the specifications on a device or troubleshoot a challenge, they know that they’ll get the support they need during their own working hours.  We are extending this value globally as we continue to create solutions that meet our demands worldwide.

The demand for big data and automation is growing rapidly among OEMs. It is also one of the most competitive markets in the world. To serve our customers with unique engineered to order designs and solutions, we work every day to stay on top of manufacturing trends and find new ways to optimize production to meet their cost and volume needs.

To learn more about Interface and our custom solution capabilities for the OEM market, please visit us at www.interfaceforce.com.

Contributor:  Brian Peters, Interface Regional Sales Director for the US

Dimensions of Multi-Axis Sensors Virtual Event Recap

The Interface ForceLeaders hosted forums are designed to answer frequently asked questions from testing engineers and product designers about new technologies and uses cases. In our recent virtual event, Dimensions of Multi-Axis Sensors, we discussed the considerations for these types of sensors, the test and measurement benefits, products Interface offers and various applications.

Interface recognizes that there are growing demands for multi-axis sensors.  In our hosted event, Interface’s Brian Peters kicked-off the conversation by highlighting benefits and reasoning for the use of these types of sensors, including answering some common questions. We’ve provided a recap of the event below or you can watch the event here https://youtu.be/zua1lvTh488.

What is Unique about Multi-Axis Sensors?

Multi-axis sensors have additional bridges to provide output signals for varying axes or types of mechanical loading. They are designed to measure a multitude of forces and moments simultaneously with a single load cell sensor. Fundamentally similar to other force and torque sensors with strain gage bridges bonded to machined “flexures,” each bridge typically defines a measurement axis. 

There are multiple configurations of 2, 3, or 6-axis options.

  • Axial + Torque
  • Axial + Shear
  • Axial + Moment
  • All 6 degrees of freedom

Should You Use Multi-Axis Sensors?

The largest factor to consider is the accuracy of your test model. In many test applications using standard load cells we often notice side or eccentric load, which can skew your data. While many Interface load cells, particularly mini load cells, have been designed to reject indirect loads, nothing can handle side and eccentric loads quite like a multi-axis sensor. Dedicated multi-axis designs are typically more balanced axis capacity limits with discrete signal outputs. Composite signal outputs are common in 6-axis models.

What are the Benefits of Multi-Axis Sensor Technology?

There are a number of benefits to using multi-axis sensors in addition to accounting for and accurately measuring or rejecting side and eccentric load. These benefits include:

  • Consolidate measurement signals, conserve test space
  • Measure unwanted system crosstalk
  • Quantify reaction loads through test article on “non-measure” side 
  • More successful fatigue testing through setup and load verification
  • More data, more understanding, more complete picture

What Considerations Should Engineer Make When Using Multi-Axis Sensors?

If you’ve made the decision to utilize a multi-axis sensor in your test model, please note the following considerations:

  • System-level loads and geometry
  • Maximum loading conditions
  • Chosen capacity is adequate for measurement loads as well as potential peak or extraneous loads
  • Choosing the right sensor based on primary axis measurements

Interface Multi-Axis Sensor Products

Ken Bishop details various types of multi-axis sensor technology from Interface during the highlighted ForceLeaders event you can watch here.  Interface offers a wide range of multi-axis sensors, including 3-axis, 6-axis, axial torsion and 2-axis versions. The product options give you the ability to measure forces simultaneously in three mutually perpendicular axes, with the 6-axis load cells also measuring torque around those axes.

AXIAL TORSION LOAD CELLS

Interface’s axial torsion load cell is used for measuring both torque and force in a single sensor. Typical applications of its axial torsion transducer include bearing test and material test machines. The features of our axial torsion load cell include minimal cross talk, extraneous load resistance, and the load cell is fatigue rated. Customers can also add the following options: an integral cable, compression overload protection, and connector protectors.

2-AXIS LOAD CELLS

The Interface 2-Axis load cells can measure in two directions, X and Y simultaneously. It is commonly used in applications where dual-axis measurement is important in design and testing. They are effective for applications that measure lateral forces and the narrow design fits into compact areas.

2-Axis Interface Products:

3-AXIS LOAD CELLS

Interface’s 3-axis load cell measures force simultaneously in three mutually perpendicular axes: X, Y, and Z – tension and compression. Each axis provides a unique mV/V output and requires no mathematical manipulation. The 3-axis load cell is built to minimize eccentric loading effects and crosstalk between axes. We offer five different models in its 3A Series 3-axis load cell designed for a wide variety of capacities. They are compact in size, provide 3 full bridge mV/V outputs with an IP68 option.

3-Axis Products:

6-AXIS LOAD CELLS

Interface’s 6-Axis Load Cell measures force simultaneously in three mutually perpendicular axes and three simultaneous torques about those same axes. Six full bridges provide mV/V output on six independent channels. A 36-term coefficient matrix is included for calculating the load and torque values in each axis. An 8-channel amplifier with a USB PC interface is also available which simplifies data analysis. The company offers five different models of 6-axis load cells for a wide variety of capacities. In the end, they provide more data, accuracy, are very stiff and cost-effective for a wide range of testing options.

6-Axis Products:

Keith Skidmore, an application expert at Interface, outlined a number of use cases spanning across multiple industries. They included testing programs using multi-axis sensors in automotive, medical, aerospace and defense, consumer packaging and more. Some of the application notes discussed during this recorded event include:

  • Wind tunnel testing
  • Aerospace structural and fatigue testing
  • Computer model validation
  • Friction testing
  • Medical device: ball socket testing
  • Prosthetics
  • Robotic arm
  • Hydrofoil
  • Seat testing
  • Center of gravity

Be sure to watch the YouTube video below to gain insight into some of the most frequently asked questions about multi-axis sensors.

We had a great time introducing our audience to the possibilities of Interface Multi-Axis Sensors. If you are interested in watching the video on demand of the webinar, you can click on the link below to watch the presentation in its entirety.

Hazardous Environment Solutions from Interface

There are hundreds of thousands of engineers and manufacturers that spend their days working in hazardous environments. Whether its operating inside of facilities with large machines with intricate moving parts, working hundreds of feet in the air repairing a bridge, or deep within a mine shaft, these professionals put themselves in danger every day by the nature of their work. As engineers and manufacturers, many of us are also tasked to solve for safety challenges and keep these professionals protected in any environment.

At Interface, one of the ways we contribute to industrial safety is with the development of our Interface Ex Rated Load Cells, also known as Interface Intrinsically Safe Products. These specialized load cells and force measurement solutions are designed and manufactured so that the materials and electronic components are safe for use in hazardous gas and dust environments when installed per applicable installation instructions. These components play an integral role in the safety of the men and women working in dangerous environments in particular industries like oil and gas, mining, aerospace, automotive and more.

These hazardous environments are categorized by the amount of explosive risk that is present in the environment. These levels include:

  • Zone Zero – explosive presence is always there
  • Zone One – explosive presence is close and is sometimes there
  • Zone Two – explosive presence is nearby, but is rarely present other than in some type of leak or other catastrophes

In order for force measurement products to operate safely in these environments, companies must design the devices in accordance with a regulatory body. These products must also be inspected for approval and then it is marked with the certification code that displays the zone and temperatures it’s safe to operate in. In addition, the manufacturing process needs to be highly controlled. Manufacturers must keep documentation for each product, which includes how the product was made and where it went. And they are required to keep that documentation for 10 years in case of a product recall.

There are a number of different regulatory bodies focused on product safety throughout the world, and each has different specifications for explosiveness that need to be met based on the area in which the product is sold. Locations in which Interface can sell its Ex Rated products include countries in North America, Europe, Asia, and Brazil in South America.

The regulatory bodies that develop the specifications and approve products include:

  • International Electrotechnical Commission Explosive Atmospheres (IECEx) is given after a manufacturer proves compliance through a quality assessment report (QAR).
  • ATmospheres EXplosible or ATEX is a European Union(EU) examination certification. In order to receive ATEX certification, the manufacturer must obtain a quality assurance notification (QAN) to sell products in certain EU areas.

Interface develops a host of Ex Rated force measurement products that are certified by both IECEx and ATEX. These products have been used in a wide variety of applications within the energy and automotive industries. Included below are a few examples of the products we sell and the applications using our Ex products

ATEX 3400 Series Load Cells

The 3400 series of load cells are rated for Zone 1 and include the 3416 and 3430 Coil Tubing Intrinsically Safe Load Cells, the 3420 Coil Tubing Intrinsically Safe Load Cell and the 3410 Intrinsically Safe LowProfile® Load Cell. These products are hermetically sealed and have been used in the oil and gas industry to measure the force of coil tubing as it goes down an oil well. The 3400 Series is used in the space industry to help develop hydrogen-powered vehicles because of the threat of explosion with hydrogen power. The 3400 Series Load Cells have also been used in a distillery for a custom whiskey-making application.

ATEX, IECEx, ETL, Inmetro 1923 Series

The 1923 Series Load Cell is used in the oil and gas industry. These load cells include designs rated for both Zone 0 and Zone 2 applications. This load cell measures the force in which the pump jack is operating to avoid allowing the pump to go too fast and interrupt the capillary flow of oil. We also recently developed and released the 1923 Wireless Series load cell. Our 1923 Wireless Series innovation provides the same accurate, real-time data readings with little to no fuss over wires, which can create more hazards for the user.

ATEX SSMH Sealed Hazardous Environment Intrinsically Safe S-Type Load Cell

Our Zone 1 rated SSMH S-Type Load Cell is our only load cell that is certified for dust, so it is most often used in mining operations. This product is a tension and compression load cell that is environmentally sealed at an IP65 rating. It also has a high-temperature rating of up to 290° F for dust environments.

ATEX IECEx Bow Type Crosby™ Cabled Load Shackle

The Interface range of ATEX IECEx load shackles is designed for lifting and weighing in rugged or harsh environments, and also meet the requirements for operation in Zone 1 and 2 hazardous areas. The shackle pins are forged from high tensile stainless steel and are machined to an exacting specification. This range of load shackles is proof loaded to 150% of the normal rated load and is available in a range from 3.25 to 400 MT (7.17K to 882K lbf). The product is internally gaged and the whole instrumented area is sealed to IP67 to protect it in service.

When operating in explosive environments, our customers need to know that their products are safe and reliable. Here at Interface, we stand by the quality of our work and the safety of our Ex Rated products. For more information on Interface’s Intrinsically Safe and Ex Rated products, please visit /product-category/intrinsically-safe/.

Contributor:  Ken Vining, Chief Engineer at Interface

Introduction to Interface Application Notes

Interface has a long history of sharing valuable resources to help our fellow colleagues and customers with various use cases for test and measurement applications. Whether it be with our in-depth technical library, the Interface Load Cell Field Guide, free access to design files for our breadth of products, or industry case studies highlighting how our customers use Interface products. Access to all of these resources is available on Interface’s website www.interfaceforce.com.

A frequently visited area of these online resources is our Interface Application Notes archive. These resourceful explainers are of interest to engineers, new product designers, metrology and engineering students, as well as T&M industry professionals.

Interface created a large collection of App Notes to showcase how Interface load cells, torque transducers, accessories and instrumentation are used by OEMs and for various test and measurement projects across all types of industries.

Each Interface App Note has the following details:

  • Name of the App Note with Primary Product
  • Industry
  • Summary of the Application Use Case Need or Challenge
  • Interface Solution
  • Results
  • Materials
  • How it Works
  • Visual Representation of the Application

Interface App Notes are great conversation starters. They help to showcase how various Interface products and systems are used across all types of industries including medical, automotive, energy, industrial automation, consumer products testing, and aerospace. Additionally, several application notes highlight specific test and measurement lab projects.

Interface Top 10 Application Notes

  1. Race Car Suspension Testing
  2. Aircraft Wing Testing
  3. Surgical Stapler Force Verification
  4. Drone Parcel Delivery
  5. Bluetooth Brake Pedal
  6. Medical Bag Weighing
  7. Seat Testing Machine
  8. Industrial Automation Friction Testing
  9. Vascular Clamp Testing  
  10. Bolt Fastening and Torque

We have many more for you to check out. Visit the entire library of Interface Application Notes here. We are adding new application notes on a regular basis, so check back frequently.

Be sure to check out the full line of Interface solutions here. If you have questions or would like to talk with our application engineering experts, drop us a note or give us a call.