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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

Prosthetic 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 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.

Interface Mini Load Cells Growing in Product Use and Testing

One of the biggest manufacturing trends over the past decade is the miniaturization of hardware components. Reducing the size and weight of products and the components, while increasing the power of complex technology systems, is growing in use across all industry segments using force measurement in design and production.

The growing trend to utilize sensor technology in miniaturized products has been especially significant in the medical, consumer products, technology and robotics industries. These industries are looking to fit more force and measurement capabilities into a package that is the same size, or in many cases, considerably smaller than previous generations of like products.

To address this expanding trend, Interface Mini™ Load Cells were designed specifically for light touch, light weight, high accuracy, and robust performance to utilize for OEM products and smaller testing applications in confined spaces. Our miniature load cells provide exceedingly accurate measurements, similar to our full-size load cells and utilize our proprietary alloy strain gages. Capacities are available as low as 0.11 lbf / 0.5 N and as high as 100 kN.

These small-scale load cells are engineered and manufactured to provide extremely accurate output data with the same degree of precision performance as our standard load cells. OEM’s must have this sort of precision force technology because many of the devices being made today are minuscule and more complex in comparison to earlier products and testing application use cases.

In the medical device industry, innovative and often small new products are used in various life-saving applications. Any inaccuracy or miscalculation of force can have devastating effects. Take a look at how our Interface LBS Miniature Compression Load Button Load Cell and 9330 High Speed Data Logging Indicator were used to record the force measurements when designing and testing vascular clamp surgical devices. You can also read about the Vascular Clamp application note here.

In our earlier Mini Load Cells 101 blog, we discussed the features and benefits of Mini Load Cells in detail. Today, we are highlighting some of our best-selling and new Mini Load Cell solutions available from Interface.

QS48 TruckSpecial Note: A large variety of our standard miniature load cells are available today through our QS48 e-commerce site for easy online ordering. Click here to order now through our QuickShip program and get your mini’s in as little as 48 hours! If you need something specifically customized, reach out to our expert application engineers who can work with you to design custom miniature load cells that will fit your exact requirements.

INTERFACE MINI™ LOAD CELLS

MB Miniature Beam Load Cell

Model MB is a miniature beam load cell used in medical test machines and a variety of low capacity applications. Performance on this product is +/- 0.03% FS and available capacities are 5 to 250 lbf (22.2 N to 1.11 kN).

Product Features:

  • Proprietary Interface temperature compensated strain gages
  • Performance to 0.03%
  • Low height – 1-inch max
  • Eccentric load compensated
  • ±0.0008% /˚F – max temperature effect on output
  • Low deflection

MBP Overload Protected Miniature Beam Load Cell

Model MBP series load cells provide similar performance to Model MB series with the added safeguard of internal overload protection. This patented overload protection is accomplished via hard stops that are EDM machined into the load cell flexure. This provides greater overload protection (2.5-10lbf ±1000% of full-scale capacity, 100 N ±500% of full-scale capacity), giving the user added protection in more severe applications.

Product Features:

  • Proprietary Interface temperature compensated strain gages
  • 10x overload protection
  • Low height – 1in max
  • 0.0008%F temp. effect on output
  • 5′ Integral Cable (custom lengths available upon request)
  • NIST Traceable Calibration Certificate

WMC Sealed Stainless Steel Miniature Load Cell

Interface Model WMC Stainless Steel Miniature Load Cell is excellent for industrial applications because of its stainless steel, sealed, environmentally protected construction. This product is available in capacities ranging from 5 to 500 lbf (22 to 2200 N).  Submersible versions of this product are available as well.

Product features:

  • Environmentally sealed tension and compression load cell
  • Proprietary Interface temperature compensated strain gages
  • Tension and compression
  • Small Size
  • Stainless Steel Construction
  • Submersible

SSM and SSM2 Sealed S-Type Load Cells

Model SSM is a moderately priced highly-accurate sealed load cell for test machines and other general purpose applications. This product is available in capacities ranging from 50 to 10K lbf (200 N to 50 kN).

Product Features:

  • Proprietary Interface temperature compensated strain gages
  • Environmentally sealed
  • 0.02% non-repeatability
  • 0.0008%/°F (0.0015%/°C) temp. effect on output
  • 0.025% creep
  • Tension and compression

LBM Compression Load Button Load Cell

Model LBM Compression Load Button is very popular.  It is constructed from stainless steel and has a small size. This product is available capacities range from 25 lbf up to 50K lbf.

Product Features:

  • Temperature compensated
  • Integral load button
  • Small diameter
  • Environmentally sealed
  • Stainless steel

LBS Miniature Load Button Load Cell

Model LBS Miniature Compression Load Button is constructed from stainless steel and has a small size. This product is available capacities range from 5 lbf up to 1K lbf (22.2 N to 4.45 kN).

Product Features:

  • Temperature compensated
  • Integral load button
  • Small diameter
  • From 0.12″ height

LWPF1 Press Force Load Washer Load Cell

Model LWPF1 Press Force Load Cell is one of several load washer load cells available from Interface. It features a large thru-hole and short overall height. This product is available in capacities ranging from 2 kN to 100 kN (450 to 22.5K lbf).

Product Features:

  • Short height
  • Large thru hole
  • For press-force monitoring

BPL Pedal Load Cell

BPL Pedal Load CellThe Model BPL is a very LowProfile® load cell is used for measuring force on brake pedals. Interface Model BPL has the lowest sensitivity to off-center loading available and will outperform any competitive model.

Product Features:

  • Lowest nonlinearity and hysteresis of any brake pedal load cell – < 0.05%
  • Ultra-low height
  • Low sensitivity to off-axis loads
  • Mounts directly to pedal with included strap(s)
  • Interchangeable mounting plates
  • For use with gas, brake or clutch pedal
  • Storage case included

There are more than 30 different Interface Mini Load Cells and sensors available, in addition to our ability to provide modified and custom Mini Load Cells solutions. To find the Interface Mini that works for your needs, or to learn more about our expanding lineup of load cells and torque transducers, please visit /products/.