What is the difference between a force transducer and a load cell?

Force transducers and load cells are based on the same measuring principle – the strain gauge – and convert mechanical forces into electrical signals. The term load cell is predominantly used in weighing and process engineering, while force transducers cover the broader spectrum of force and torque measurement technology: from test benches in the aerospace industry to materials testing. interfaceforce® eK distributes both types in measuring ranges from 0,5 Newtons to 30 Meganewtons.

What types of force transducers does interfaceforce® eK offer?

The portfolio includes low-profile force transducers, S-shaped force transducers, miniature force transducers, measuring bolts, force rings, bending beam load cells, cylindrical high-load sensors, and multi-component transducers for up to 6 degrees of freedom (6DoF). All standard models are strain gauge based and supplied with a calibration certificate. Custom designs are developed according to customer specifications.

Which torque transducers are suitable for rotating applications?

For rotating shafts, torque measuring shafts (e.g., T2, T4, T6, T8, T11, T22, T25) are available, which operate without contact and without slip rings. The measuring ranges extend up to 10 kN·m. For static or reactive applications – such as in test benches or for measuring bolt preload – reaction torque transducers are used. Both variants provide strain gauge-based signals and are compatible with the measuring amplifiers from interfaceforce® eK.

How does the XSENSOR pressure distribution system work and what is it used for?

XSENSOR systems measure surface pressure distribution using ultra-flexible sensor mats in various geometries and resolutions. These imaging systems deliver precise, reproducible results and are used in automotive and medical technology, biomechanics, and point-of-sale applications – for example, for seat pressure analysis, tire contact patch measurement, mattress diagnostics, and wiper testing. The XSENSOR laboratory is accredited according to ISO/IEC 17025 (A2LA).

What measurement accuracy do the force transducers from interfaceforce® eK achieve?

The low-profile force transducers of the Interface series (e.g., 1200, 1201, 3200) typically achieve a total static error band of ≤ 0,02% of the nominal value (full-scale output). The Gold Standard® and Platinum Standard® reference force transducers are suitable for calibration tasks according to ISO 376 Class 0,5. All sensors are supplied with a calibration certificate; A2LA-accredited certificates according to ISO/IEC 17025 are available upon request.

Does interfaceforce® eK also perform calibrations of third-party sensors?

Yes. The calibration laboratory of interfaceforce® eK is ISO/IEC 17025 accredited (A2LA and DAkkS mutually recognized within the framework of the ILAC MRA) and calibrates force measuring devices regardless of the manufacturer. Supported standards: ISO 376, DKD-R 3-3, ASTM E74, VDI/VDE 2624, and custom calibration procedures. Force measuring ranges: 0,5 N to 250 kN (tension and compression). An RMA number will be issued in advance for submissions; the delivery address for calibrations and repairs is c/o SETFLEX, Oppelner Str. 23, 41199 Mönchengladbach, Germany.

How does a calibration process work and how long does it take?

The process begins with an inquiry via contact form or email; interfaceforce® eK promptly issues an RMA number. Upon receipt of the device, calibration is performed in an ISO 17025-accredited laboratory using static tensile and/or compressive force measurements with traceable transfer standards (DAkkS, NIST, or PTB). Calibrations according to ISO 376 or DKD-R 3-3 include multiple load stages in various mounting positions. Turnaround times are short – precise details are available upon request. The completed calibration certificate is internationally recognized.

Which force transducers are suitable for use in ATEX or explosion-hazardous areas?

For hazardous areas (ATEX/IECEx), interfaceforce® eK offers force transducers from the 3400 series as well as hermetically sealed sensor variants made of stainless steel. These models are designed for harsh and potentially explosive environments and deliver reliable measurement results even under continuous operation. For specific hazardous area requirements (Zone 1, Zone 2, etc.), we recommend individual consultation, as suitability depends on the respective device category and the medium being used.

From what quantity are special solutions and customer-specific force transducers available?

Custom designs are available even for single units. interfaceforce® eK develops customer-specific force transducers, torque transducers, and multi-component sensors based on over 25 years of experience and in-house strain gauge manufacturing. Rapid engineering and rapid prototyping enable solutions to be implemented in short lead times – from concept to series production. Application areas range from niche markets with small production runs to OEM integrations in high-volume series.

What distinguishes interfaceforce® eK from other providers in force measurement technology?

interfaceforce® eK has been the exclusive distributor in Germany for Interface Inc. (founded in 1968, Scottsdale, USA) since 1999 – one of the world's leading manufacturers of precision strain gauge-based force transducers. The service portfolio combines American manufacturing quality with local support: an ISO 17025-accredited calibration laboratory in Germany (A2LA/DAkkS, ILAC MRA), manufacturer-independent calibrations and repairs, custom manufacturing starting from a single unit, and exclusive distribution of XSENSOR pressure distribution systems. Measuring ranges from 0,5 Newtons to 30 Meganewtons cover virtually every industrial force measurement application.

What output signal do the force transducers provide, and what measuring amplifier do I need?

Strain gauge-based force transducers deliver a bridge signal of typically 2 mV/V or 4 mV/V at rated load. Further processing requires a measuring amplifier that converts this signal into a usable format – e.g., 0–10 V, 4–20 mA, USB, IO-Link, or digital interfaces. interfaceforce® eK offers suitable measuring amplifiers as complete measurement chains: from simple digital displays (IFFDA93, IFFDA5) and 8-channel data acquisition systems (IFFBX8) to wireless telemetry systems (WTS). Sensors with a TEDS chip also enable automatic parameterization at the measuring amplifier.

What protection ratings (IP classes) are available for the force transducers?

Most standard models are designed for industrial use and achieve protection ratings of IP65 to IP67 (dustproof, protected against water jets and temporary immersion). Hermetically sealed versions made of stainless steel achieve IP68 and are suitable for underwater, cleaning, and outdoor applications under harsh conditions. Certified versions are available for use in potentially explosive atmospheres (ATEX/IECEx). The exact IP rating can be found in each product data sheet; interfaceforce® eK is available upon request to advise on application-specific selection.

How often should a force transducer be recalibrated?

There are no legally mandated intervals; however, ISO 9001, IATF 16949, and industry-standard quality assurance systems recommend annual verification. In practice, the interval depends on the intensity of use, environmental conditions, and the required measurement uncertainty. In safety-critical applications or after mechanical overload events, immediate recalibration is recommended. The interfaceforce laboratory performs manufacturer-independent recalibrations with short turnaround times – even for sensors from other manufacturers.

What is TEDS and what advantages does it offer?

TEDS (Transducer Electronic Data Sheet, IEEE 1451.4) is an electronic data storage device integrated into the sensor or connector that automatically transmits calibration data and sensor characteristics to the measuring amplifier. This eliminates manual input and parameterization errors when replacing sensors – the measurement setup is ready for operation via plug-and-play. The IFFDA93 handheld device and other measuring amplifiers from interfaceforce® eK support the TEDS standard and enable quick, error-free commissioning, even with frequent sensor replacements.

What are parasitic forces and how do they affect measurement?

Parasitic forces are unwanted shear forces, bending moments, or torsional loads that act on the sensor simultaneously with the actual measuring force and can distort the result. Even an angular deviation of 5° in the load application causes a systematic error. To minimize parasitic influences, interfaceforce® eK recommends using rod ends, pressure load buttons, and mounting plates – all available as accessories. The interfaceforce® eK team provides support for sensor selection and installation advice upon request.

What are the delivery times and can I order small quantities?

Standard models from Interface Inc. that are in stock are available for immediate delivery. Custom designs and customer-specific receivers are manufactured upon receipt of order; thanks to rapid prototyping, initial samples are often available within a few weeks. There is no minimum order quantity – orders are possible starting from a single unit. Inquiries and orders can be made via email (info@interfaceforce.de), telephone (+49 8022 271667), or the contact form on the website.

Fatigue testing with interface load cells

Engineers rely on fatigue testing to ensure the safety and reliability of their product designs and structures. By understanding how materials behave under repeated loading, engineers can develop components that are resistant to fatigue fracture.

fatigue tests require accurate and reliable force measurement. Interface uses the term “fatigue resistant” as an exact specification that defines a specific class of load cell design and construction. Fatigue tested load cells from Interface are engineered to withstand repeated loading, making them ideal for even the most demanding, high-cycle fatigue testing applications.

In a typical fatigue test setup, fatigue-rated load cells are attached to the sample or testing machine and cyclic loading is applied according to the test protocol. The load cells continuously record the applied forces or stresses, allowing engineers and researchers to monitor how the material responds to repeated loading.

By analyzing data from interface load cells, researchers and Materials engineers determine the load limit, fatigue life and stress-strain behavior of the material. This information is invaluable for optimizing material selection, design and manufacturing processes to improve product performance and reliability while identifying fatigue and potential failure risks.

For the most Testing and measurement applications is the use of load cells with fatigue properties and data acquisition devices required, especially when materials, parts or assemblies are being tested for destruction. Only by accurately recording the forces at each point of testing can an engineer analyze the stresses that occurred in the moments just before final failure. Read more about Fatigue testing in the Interface Technical Library.

Fatigue Rated Load Cells from Interface

Profile of a fatigue load cell

The stress values in the bends are approximately half those of a standard low-profile load cell.
Internal high voltage points, such as B. sharp corners and edges are specially polished to prevent cracks from spreading.
The sensitivity to extraneous loads is specified and set to a lower level than a standard low-profile load cell.
All Interface fatigue-rated load cells have a specified lifespan of 100 million fully reversed load cycles at full capacity.

No one can predict exactly when failure will occur or which part of an assembly will be the weakest link that eventually fails. For this reason, high cycle testing is the best method for measuring fatigue life. More information about fatigue testing and the Fatigue theory you find in Load Cell Field Guide by Interface.

Applications of fatigue testing

Interface fatigue resistant load cells are used in a variety of industries including aerospace, automotive, construction and manufacturing. They are used to test various products, from aircraft wings and undercarriages to furniture and Industrial machines.

How fatigue rated interface load cells are used in fatigue testing:

Aerospace: Interface's fatigue-rated load cells test the durability of aircraft wings, landing gear and other components Aerospace. This helps aircraft withstand the rigors of repeated takeoffs, landings and flights. These load cells are used to test the materials used in structures and even rockets.
Automotive: Fatigue-rated interface load cells test the fatigue life of engine components, chassis and suspension systems. This contributes to that Vehicles are safe and reliable and can withstand the stresses of daily driving.
Construction: Fatigue-rated interface load cells test the fatigue strength of bridges, buildings and critical infrastructure. This ensures that these structures can withstand the loads they are designed for and are safe for the public.
Manufacturing: Interface's fatigue-rated load cells test the fatigue life of industrial machines, tools and consumer products. This helps ensure that these products are reliable and can withstand the demands of everyday use.

See how Interface Load Cells are used in this bicycle frame testing application.

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Since its founding in 1968, Interface has specialized in fatigue load cells and their applications. Our LowProfile® fatigue-resistant load cells provide up to 100 million duty cycles, and the calibrated sensors in each load cell are individually inspected, tested and certified to meet our rigorous performance standards.

Choosing the right load cell for your fatigue testing application is critical. Load cells come in a variety of sizes and capacities, so it is important to choose the right one for your fatigue testing application. Make sure you know the maximum load placed on the load cell, the type of load, the accuracy requirements, and the environmental conditions for the test. Contact Interface's application engineers to find the appropriate load cell for your testing needs.