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 S-Type Load Cells 101

There are many different types of devices used in test and measurement from load cells to torque transducers and tension links to multi-axis sensors. In addition, there are sub-categories in each of these product types that are based on various specifications, capabilities, capacities, and application requirements.

Discussing load cells specifically, there are different models and configurations depending on the use case, the amount of force measurement or weighing requirements for a particular load, dimensions, and even test environment considerations. No matter what our customers need, we have standard and custom load cells up to the task. In our 101 series, we are highlighting the innovative miniature load cell sub-category of Interface S-Type Load Cells.

What Is an S-Type Load Cell and What Is It Used For?

S-type load cells, sometimes called s-beam, gets its nomenclature from the “S” looking model of the load cell. It is shaped this way because it is designed to measure well-controlled tension and compression forces. There are preferred by engineers and testing labs for the precision, size, material, and ability to fit in limited spaces. They are often used for weighing, in test machines as well as product designs for ongoing performance measurement by OEMs.

An s-type load cell will often be used within a system designed to stress test products in a controlled environment for fatigue and product testing to measure the way the product stands up to force over long periods of time. The benefit of Interface S-Type Load Cells is that they are very cost-effective, highly accurate, easy to mount, and offer flexibility because it can be used universally for tension and compression testing. They are also smaller than typical load cells, providing major benefits when there are limitations in space or for smaller test product dimensions.

Interface has a wide range of specialized miniature s-type load cells including sealed, micro-size, fatigue-rated, high-temperature ratings, low height, overload protected and intrinsically safe to meet all types of testing protocols and plans. You can see all the s-type models here.

An s-type load cell is generally used with eyebolts or rod-ends when used in tension and this can cause binding or the associated hardware to unthread. These uniquely designed load cells should not be used when weighing an object that can sway or rotate. Additionally, an s-type load cell is not recommended when the load cell will be used for both tension and compression, where accuracy in compression is critical. In this case we’d recommend a shear type of load cell.

S-Type Load Cell Applications

Prosthetics Load and FatigueProsthetic Load and Fatigue Testing

Prosthetic limbs must be tested for extreme loading that can occur during falls, accidents, and sports movements. Fatigue testing of prosthetic components determines the expected lifespan of the components under normal usage. Interface suggested a static load test apparatus using SSMF Fatigue Rated S-Type Load Cell attached to hydraulic actuators to apply and measure loads. The fatigue testing machine uses SSMF Fatigue Rated S-type Load Cell to apply and measure cyclic loads. During the fatigue test, the actuator repeatedly applies and removes the force to simulate activity such as walking. Tilt tables may also be used to apply forces at various angles to simulate the heel-to-toe movement of walking or running. Using this solution, engineers can determine whether prosthetic materials and designs will withstand the rigors of daily use and occasional high load situations. Read more here.

Furniture FatigueFurniture Fatigue Cycle Testing

To meet safety protocols in relation to the manufacturing of various furniture products, fatigue testing, shock testing, and proof testing must be rigorously performed before diffusion into the marketplace. Force testing simulations on furniture products are critical in determining the posted max loads to protect manufacturers from liability due to damages that might result from the misuse of those products and overloading. Using an Interface Model SSMF Fatigue Rated S-Type Load Cell along with Interface Model 9890 Strain Gage, Load Cell, & mV/V Indicator provides a solution that measures the force being applied in fatigue cycle testing of a furniture product, in this case testing the rocking mechanism in an office chair. Unlike other similar load cells, the Model SSMF is fatigue rated making it highly suitable for fatigue testing. No fatigue failure of any fatigue-rated Interface load cell, used within its ratings, has ever been reported. The furniture manufacturer was able to obtain accurate data about the rocking mechanism the office chair as it was fatigue cycled into failure. Adjustments were made to the design to improve the safety and life of the furniture, ensuring product quality and protecting the manufacturer from future liability. Read more here.

Interface S-Type Load Cells are highly effective, accurate and flexible products used for a wide variety of applications needing compression and tension force testing. To learn more about Interface’s S-Type Load Cells, you can also visit here or call us today to speak to an application engineer who can help you select the right product for your next project at 480-948-5555.

Mini Load Cells 101

With the miniaturization and compact size of many products and technologies used in today’s market, it is critical that sensors are designed to fit all types of applications both big and small. This is especially true in the medical, aerospace, industrial automation, and automotive industries.

Interface customer’s requirements for miniature load cells has rapidly expanded the diversification of load cell products that are “mini” in capacities as low as 0.11 lbf / 0.5 N and as high as 100 kN. Interface Mini Load Cell solutions include miniature beam load cells, miniature sensors, load buttons, load washers, tension force mini load cells, S-type load cells, and sealed stainless steel load cells.

Interface’s mini load cells are used for customers who are looking for smaller cells, or for those designing for light touch or lightweight products. Our miniature load cells provide exceedingly accurate measurements similar to our full-size load cells, all with proprietary alloy strain gages. Mini’s are available standard and can be modified, as well as completely customized depending on the exact requirements of the client’s project or embedding into original equipment. Decreased size should never equal less accurate measurements. Our customers can expect Interface miniature load cells perform with the exact quality and accuracy as all our larger load cells.

To provide you with more insight, here is a quick overview of some of Interface’s most popular mini load cells and their unique capabilities. You can download the full Interface Mini Load Cell brochure here.

Load Buttons

Interface’s load button cells are designed for customers who require the measurement of forces in a very confined space. They are designed to provide the most accuracy in as little space as possible. The smaller LBM or LBS can fulfill the need for force measurements at a very respectable precision level that is enough for most applications. Diameters range from 1 inch to 3 inches, with heights from 0.39 inch to 1.5 inches. The shaped load button has a spherical radius to help confine misaligned loads to the primary axis of the cell.

S-Beam Cells

This line is designed for customers looking for extremely compact load cells that still offer great accuracy. The SM (Super-Mini) series load cells are a low-cost, yet accurate, cell with a straight-through loading design. The SSM (Sealed Super-Mini) series offers the same benefits as the SM series with a rugged S-Cell with a splash-proof cover. Both series give exceptional results in applications that can be designed to operate the cell in tension. Some caution should be exercised when using these cells if they will be compressed to ensure that the loading does not introduce side loads into the cell.

Bending Beam Cell

With Interface’s bending beam cell, the cell is bolted to support through the two mount holes. The cell is designed to concentrate the forces into the area where the gages are mounted on the top and bottom faces of the beam. Our line of bending beam cells also have a splash-proof sealing cover.

Double Bending Beam Cell

The double bending beam cell from Interface is a useful variation on the traditional bending beam. In general, this configuration is much more user-friendly because of its short vertical dimension and compact design. It is especially useful for applications where the cells could easily be damaged by tension/compression overload. The variation is achieved by forming two bending beams into one cell. This allows the loading fixtures to be attached at the threaded holes on the centerline, between the beams, which makes the sensitive axis pass through the cell on a single line of action.

Interface mini load cells can be ordered in different sizes, with a wide range of capacities. Many of the minis can be used in off-the-shelf applications. We are also happy to work with customers to custom design load cells to fit their exact needs for size, weight, and accuracy.

For more information on Interface’s Mini Load Cells, visit our web product page or review our product brochure below for detailed specifications on every product.

Mini Load Cell Brochure_6-Page

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