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Basics on Load Cell Base Kits

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As resilient and accurate as load cells are engineered, there is risk of damaging a load cell if they are not properly supported through mounting or mating to the test subject or test bench.

Load cell bases are designed to support and stabilize load cells. Load cell bases come in assorted sizes and configurations, depending on the intended application and the weight capacity.

Load cell bases are used with load cells that are frequently utilized in industrial equipment, test machines, and commercial testing labs. They may also be integrated into several types of equipment, such as weighbridges, conveyor systems, structural test stands, and packaging machines.

Interface publishes numerous guides on properly supporting a load cell during a test. However, for our LowProfile™ load cells, we provide complete Load Cell Base Kits to provide the engineered accuracy and necessary support for precision performance as intended in regular use. Bases minimize risks in damaging load cells from improper use.

Load cells with positive overload protection must be ordered with an Interface installed base. The positive overload option is useful when high overloads occur in applications such as: impact loads on weighing platforms; engine malfunctions during rocket or jet engine testing; transient overloads on engine dynamometers.

Interface’s Load Cell Base Kits are a type of mounting plate guaranteed to provide optimum support for the flexure. Using the base, or a support surface with its equivalent flatness and stability, is required to ensure the exceptional performance. They are heat treated and high strength bases, available in all standard sizes of our low profile models.

Standard thread size is the same as the mating load cell. Bases or flat mounting surfaces are required for all low profile load cell installations. A mounting surface that is flat to 0.0002″ T.I.R. (total indicator reading) is required, unless a base is installed.

Use of the base, or a support surface with its equivalent flatness and stability, is required to ensure the exceptional performance of the LowProfile® Series.

The threaded hole in the base is on center, and a plug is permanently installed to seal dirt and moisture out of the space between the bottom hub of the flexure and the flat surface of the base. Center hub deflects under the load until it contacts the base which provides positive overload protection. The center tapped hole is sealed to keep overload surfaces clean.

When the base and load cell are ordered together, the base and plug are factory installed using the proper hardware tightened to the required torque specs. A plug is supplied in between the cell and the base to prevent damage or errors caused by over engagement of mating parts.

There are 14 model options in standard Load Cell Base Kits in both U.S. and Metric Threads. They are available for our standard 1000 and 1200 Load Cell Series of various capacities. We offer 15 stainless steel model options to be paired with our 2400 and 3200 Load Cell Series.

Load Cell Base Kits are an excellent accessory to ensuring the most out of your LowProfile Load Cells provide the performance as designed. For complete instructions on installations, please reference our Support section on the website.

ADDITIONAL RESOURCES

Accessories

Load Cell Basics Sensor Specifications

Interface Presents Load Cell Basics

Technical Library

Force Measurement Installation Guides

Mechanical Installation Load Cell Troubleshooting 101

Off-Axis Loading 101

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Off-axis loading refers to a situation where a load cell, which is a device designed to measure force or weight, is subject to forces that are not aligned with its primary sensing axis. Load cells are typically designed to measure forces that are applied along a specific direction or axis, which is known as the primary sensing axis. When forces are applied to the load cell in other directions, this is referred to as off-axis loading.

Off-axis loading can affect the accuracy of load cell measurements, as the load cell may not be able to accurately distinguish between forces that are applied along the primary sensing axis and forces that are applied in other directions. This can result in errors in the measured weight or force.

To minimize the effects of off-axis loading, load cells are often designed with measures to reduce sensitivity to forces applied in other directions. These may include mechanical features such as strain relief structures or specialized materials that are more resistant to off-axis loading. Additionally, load cells are often installed and used in ways that minimize the likelihood of off-axis loading, such as aligning the primary sensing axis with the direction of the applied force. Be sure to carefully follow all Force Measurement Installation Guides provided with sensor.

What can be done to protect from off-axis loading?

Off-axis loading can affect the accuracy of load cell measurements, so it is important to take steps to protect against it. Here are a few ways to do so:

  • Use proper mounting and alignment: Load cells should be mounted and aligned in a way that ensures that the primary sensing axis is aligned with the direction of the applied force. This helps to minimize off-axis loading and ensure accurate measurements.
  • Use appropriate accessories: Using accessories such as adapters or mounting bases can help to ensure that load cells are properly aligned and oriented, minimizing the potential for off-axis loading.
  • Use anti-rotation features: Many load cells are equipped with anti-rotation features, such as bolt-hole patterns or keyway slots, which help to prevent the load cell from rotating around its mounting point. This can help to maintain proper alignment and reduce the effects of off-axis loading.
  • Use overload protection: Overload protection features, such as limit switches or stoppers, can be used to prevent load cells from being subjected to excessive forces or moments. This can help to prevent damage to the load cell and ensure accurate measurements.
  • Use a protective enclosure: Load cells can be placed in protective enclosures that shield them from external forces and environmental factors. These enclosures can help to protect against off-axis loading, as well as other types of interference.

By taking these steps, load cell users can help to protect against the effects of off-axis loading and ensure accurate and reliable measurements.

Product designs that mitigate off-axis loading

Engineers are constantly working to design new load cells that are more resistant to off-axis loading.  In fact, Interface product engineers have several products that are designed to protect from off-axis loading, including:

  1. ConvexBT Load Button Load Cell
  2. SuperSC S-Type Miniature Load Cell
  3. MBP Overload Protected Miniature Beam Load Cell
  4. MRTP Miniature Overload Protected Flange Style Reaction Torque Transducer
  5. MBI Overload Protected Miniature Beam Load Cell
  6. LBMP Overload Protected Compression Load Button Load Cell
  7. SMT Overload Protected S-Type Load Cell
  8. WMCP Overload Protected Stainless Steel Miniature Load Cell with Male Threads

By optimizing the mechanical design of load cells to minimize their sensitivity to off-axis loading this can include use of materials, such as composites or alloys, which are more resistant to deformation and strain. It also includes the use of specialized geometries that can help to distribute forces more evenly and reduce the effects of off-axis loading.

As well, engineers utilize built-in electronic compensation to correct for the effects of off-axis loading. This may involve using additional sensors or feedback loops to monitor the load cell’s response to external forces and adjust the output accordingly.

Interface engineers use a multi-disciplinary approach to designing load cells that are more resistant to off-axis loading. By combining advances in mechanical design, electronics, manufacturing, and simulation, they are creating load cells that are the most accurate in by classification in the world.

ADDITIONAL RESOURCES

ConvexBT – The Most Innovative Load Button Load Cell

Eccentric Loading Analysis for SuperSC S-Type Miniature Load Cell White Paper

Addressing Off-Axis Loads and Temperature Sensitive Applications

Benefits of Proof Loading Verification

How Do Load Cells Work?

Mechanical Installation Load Cell Troubleshooting 101

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The performance of a load cell force measurement system is dependent upon the reliability of the physical installation, correct interconnection of the components, proper performance of the basic components which make up the system, and calibration of the system.

Interface provides installation instructions for our products. Review the installation guide and keep on hand for installation and troubleshooting. Load cells not mounted in accordance with the manufacturer’s recommendations may not perform to the design specifications.

Always start any troubleshooting with a physical inspection of the load or weighing sensor. Resistance results from numerous factors, creating an inaccurate reading of the measurement and potential overload. If there is any appearance of dents, bending, cracks or deformation it is likely the device will need to be repaired or replaced. If none of these conditions are visible, the next step is to troubleshoot the mechanical installation.

The following is a quick checklist to reference for mechanical installation troubleshooting:

  • Check the mounting surfaces for cleanliness, flatness, and alignment
  • Check the torque of all mounting hardware
  • Check the load cell orientation
  • Check use of proper hardware as required to connect the load to the load cell
  • Check cables or output devices

Orientation is of a load cell is defined by the “dead” end on mechanical reference or load forcing source and the “live” end connected to the load to be measured by the cell. Dead end is the end closest mechanically to the cable exit or connector. A fundamental requirement is that there be one, and only one, load path.  This load path must be through the load axis of the load cell. This may sound elementary; however, it is a commonly overlooked problem.

Check all hardware and accessories when troubleshooting during mechanical installation, including all connectors, cables, thread sizes, jam nuts, swivels, mounts, and bolts. It is always important to also thoroughly inspect the cables used in a system. Evaluate the cable to ensure there is no crimping, cuts, or exposed wires. This is a common cause of mechanical installation failure.

For a quick reference, here is a discussion about what a healthy load cell should look like, and any visual clues that may potentially be a sign for an improperly working load cell.

For more helpful guides and troubleshooting tips, please visit the Interface Technical Library. Interface provides technical support for additional questions related to installation or if there is help needed in troubleshooting any of our products. Contact us here and let us know how we can help.

Additional Resources

Force Measurement Installation Guides

I’ve Got a Load Cell, Now What Play List

Force Measurement Accessories 101

 

How to Choose the Right Load Cell

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Load cells are used to test and confirm the design of hardware, components, and fixtures used across industries and by consumers. From the structural integrity of an airplane to the sensitivity of a smartphone touchscreen, there’s a load cell available to measure force. In fact, here at Interface we have over tens of thousands of products used in force measurement, for all types of different applications.

How do engineers and product designers go about choosing the right load cell for a specific application or testing project?

Have no fear, Interface has put together a short guide on choosing the load cell that is right for you. This blog will cover the basic questions to answer when selecting a product, as well the most important factors affecting load cell choice.  Be sure to watch the online video, Load Cell Basics, that highlights key factors of consideration when choosing the right load cell for additional insights.

The basic questions you need to consider when selecting a load cell include:

  • What are the expected loads? What is the minimum and maximum load you’ll be measuring?
  • Is there any potential for higher peak loads than what you intend to measure? What are these expected peak forces?
  • Is it tension, compression, or both?
  • Will there be any off-axis loads? If so, what is their geometry? Do you want to measure them too?
  • Will it be a static, dynamic or fatigue measurement?
  • What is the environment in which you’ll be conducting your test? Will the load cell need to be sealed?
  • How accurate do your measurements need to be? Do they need to be at the highest accuracy of ±0.02-0.05% or within ±0.5-1%?
  • What additional features, accessories and instrumentation does your application require to complete a test?
  • Do you need standard electrical connectors or customized options? What about additional bridges or amplifiers?
  • How are you planning to collect and analyze the data output from the load cell?

Next, these are the most important factors affecting accuracy, which will have a heavy influence over the load cell you choose. It’s important to understand how your application and the load cell will be affected by each of the factors, which include:

  • Mechanical – Dimensions and Mounting
  • Electrical – Output and Excitation
  • Environmental – Temperature and Moisture

One of the most important factors in choosing the right load cell is understanding how it will be mounted for testing or as a component within a design. There are a wide variety of mounting types including threaded connections, inline, through hole or even adhesive. Understanding the mounting type that suits your application is critical to getting the correct data because a poorly mounted load cell will distort the results and can damage the load cell.

The mounting process also requires you to understand which direction the load is coming from, in addition to any extraneous loads that may be present. The load cell mating surface is also an important factor. For example, when using our LowProfile® load cells without a pre-installed base, the best practice is to ensure that the mating surface is clean and flat to within a 0.0002-inch total indicator reading and is of suitable material, thickness, and hardness (Rc 30 or higher). Also make sure that bolts are torqued to the recommended level.

If you’re conducting a fatigue measurement, it’s also important to address the frequency and magnitude of load cycles with your load cell provider. Factors to address include single mode versus reverse cycles, deflection versus output resolution, and material types. Interface offers a wide variety of fatigue-rated load cells that are perfect for these types of applications.

Another consideration in choosing the right load cell is the electrical signal. Load cells work by converting force into an electrical signal. Therefore, it’s important to understand the electrical output type necessary for your application, which could include millivolt, voltage, current or digital output. You can find the excitation voltage data on our website for each of our load cells. Additional considerations include noise immunity, cable length and proper grounding.

The environment is also a critical factor in ensuring accurate performance of your load cell. Interface provides load cells in a variety of material types including aluminum, steel, and stainless steel. Each material has a variety of properties that make them more suitable for different environments. For a more in-depth perspective on the different strengths and weaknesses of materials, please read our blog titled, Considerations for Steel, Stainless Steel and Aluminum Load Cells. For applications where load cells need to be submerged in liquid or enter an explosive environment, we also have a variety of harsh environment and IP rated load cells, in addition to load cells suitable for high humidity or splash resistance. Learn more about our intrinsically safe load cells here.

Learn more about choosing the right load cell in these online resources:

WATCH: Load Cell Basics with Keith Skidmore

WATCH: How to Choose a Load Cell with Design Engineer Carlos Salamanca

READ: Load Cell Field Guide

VISIT: Interface Technical Library

To learn more about choosing the right load cell for any application, connect with our applications engineers about the force measurement needs for your next project at 480-948-5555.

Force Measurement Accessories 101

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When purchasing a new piece of force measurement technology, it is equally important to consider how you will accessorize it to optimize its utility.  Just like whether you’re wrapping your brand-new smartphone in a protective case to protect your asset or outfitting your new vehicle with top of the line wheels or smart devices to personalize it for your exact needs, accessories are essential to getting the most value out of your investment. This is no different in test and measurement applications.

Accessories ensure you get fully functional and accurate use of your force measuring equipment.

Interface provides the most accurate and reliable force measurement load cells and torque transducers on the market. We also supply vital accessories to pair with our products, including cables, adapters, load buttons, mating connectors, rod end bearings, and TEDS. Our accessories are high-quality components and utilize our stringent processes to ensure your Interface products perform to meet their published specifications utilizing Interface accessories.

Here is a quick overview of why you should consider certain accessories based on your application, along with some of the products we offer to properly accessorize and optimize the performance of your force measurement components.

Why Would You Need Force Measurement Accessories?

Accessories assist with the reliability and performance of load cells and torque transducers. They can also help certain products adapt to various applications. There are a few questions we ask our customers to consider when purchasing a load cell, transducer or other Interface test and measurement products.

  1. How and where is the Interface product connecting to your application?
  2. Are adapters necessary to make the product fit your application?
  3. Are you mounting the device to a hardened flat surface?
  4. How will you be monitoring the performance of your application?

These type of questions are an important step to determine the right accessories for each application, or if a custom accessory is necessary for your testing program. Our experienced Application Engineers can work with you to determine which accessories you need.

Interface Accessories

Cable Assemblies – We provide high-grade cables and connectors to ensure the maximum performance of force and torque systems. This includes standard and custom length shielded cables for connecting transducers to instrumentation.

Calibration Adapters – Our off-the-shelf and custom calibration adapters greatly improve and maintain transducer accuracy. Interface uses high-grade alloy and stainless steel, heat treatments and quality machining practices to ensure our adapters meet your performance needs.

Clevises – We provide high-grade clevises that will perform in your application as needed while maintaining the level of performance you expect from our products. Our clevises are precision machined to ensure performance, reliability, and durability.

Jam Nuts – In order to ensure strength and performance, jam nuts are utilized to maintain a tight bond between the application. We manufacture our own high-performance jam nuts for flat, parallel surfaces in multiple thread sizes.

Load Buttons – Load buttons are used for Interface LowProfile™, S-Type and Mini Beam Load Cells to convert a universal cell to compression only.

Mating Connectors – To match interconnects between load cells and instruments we provide high-grade, off-the-shelf and custom mating connectors to guarantee the performance of your readings are not compromised by a defunct connection.

Mounting Plates – Mounting is a critical factor in the accuracy and durability of force measurement tools. Our mounting plates are made from the best grade alloy and stainless steel and are machined to the tightest specifications. This ensures the load is properly distributed over the foundation of the supporting structure and provides a prepared surface for the load cell. Mounting plates eliminate the requirement for expansion assemblies in most installations.

RCAL Resistors – Interface RCAL Resistors are high precision components that provide an effective method for checking the calibration of a load cell system in the field or when a means of applying actual forces are unavailable.

Rod End Bearings To reduce alignment errors in tension applications, Interface provides high-grade Rod End Bearings that help couple your load cell to your application solution while maintaining performance.

Thread Adapters – Thread adapters provide flexibility to users when workings with male and female threads of differing sizes. Our thread adapters are manufactured with the best practices to ensure the performance of your transducer is maintained when attached to your force transducer application.

Transducer Electronic Data Sheet (TEDS) – Interface’s TEDS option provides a force or torque transducer with electronic identification, allows a sensor or an instrument to be “Plug and Play Ready”, meets IEEE 1451.4 Standard for Smart Transducer Interface and is available on new or existing sensors.

From top to bottom, Interface’s goal is enabling our customers to get the most out of their force measurement device. By combining our industry-leading products with our top-of-the-line accessories, you are certain to get the greatest value in your precision-based application test. For more information on our wide variety of standard and custom accessories, click here.

For additional information about the range of accessories available along with valuable tips about cables, TEDs, and mounting plates read or download the brochure below.
Accessories Brochure