Posts

Calibration Curve 101

Calibration curves are essential for ensuring the accuracy of force measurements. They are used in a wide variety of test and measurement applications, including quality control, research, and engineering.

A calibration curve is a graph that shows the relationship between the output of a measuring instrument and the true value of the quantity being measured. In force measurement, a calibration curve is used to ensure that the force measuring device is performing accurately. In the context of load cell calibration, a calibration curve is a graphical representation of the relationship between the output signal of a load cell and the applied known loads or forces.

The load cell user will use a known force standard to create the calibration curve. The known force standard is applied to the force measuring device and the output of the instrument is logged via the supporting instrumentation. This process is repeated for a range of known forces.

The calibration curve for a load cell is created by plotting the output signals (typically in voltage or digital units) on the y-axis against the corresponding applied loads or forces on the x-axis. The resulting graph is the calibration curve.

Test and measurement professionals use the calibration curve to convert the load cell output to the true value of the force being measured. The curve helps to establish the relationship between the load and the output signal, and it provides a means to convert the load cell’s output into accurate force or weight measurements. For example, if the output is 100 units when a known force of 100 N is applied, then the calibration curve will show that the measurement using the load cell is accurate to within a certain tolerance.

Benefits of using a calibration curve in force measurement:

  • It ensures that the force measuring instrument is accurate and dependable.
  • It provides a way to convert the load cell output to the true value of the force being measured.
  • It can be used to identify and correct errors, including drift, sensitivity, overload and hysteresis.
  • It should be used for traceability and to track the performance of the measurement device over time.

Why does a calibration curve matter when calibrating load cells?

Load cells can be affected by a range of factors, including temperature variations, drift, and environmental conditions. The calibration curve helps identify and compensate for these factors. By periodically calibrating the load cell, any deviations from the original calibration curve can be detected, and appropriate corrections can be made to ensure accurate and reliable measurements.

The calibration curve for a load cell should be linear, indicating a consistent and predictable relationship between the applied load and the output signal. However, load cells may exhibit non-linear behavior, such as sensitivity variations or hysteresis, which can be accounted for and corrected through calibration.

The calibration curve allows for the determination of the load cell’s sensitivity, linearity, and any potential adjustments or corrections needed to improve its accuracy. It serves as a reference to convert the load cell’s output signal into meaningful and calibrated measurements when the load cell is used in practical applications for force or weight measurement.

Calibration curves are an essential tool for ensuring the accuracy of force measurements. They are used in a wide variety of applications, and they offer several benefits. If you engage in using load cells, it is important to understand the importance of calibration curves and how they can help you ensure accurate measurements.

Find all of Interface 101 posts here.

Interface recommends annual calibration on all measurement devices. If you need to request a service, please go to our Calibration and Repair Request Form.

ADDITIONAL RESOURCES

Interface Calibration 101

Interface Guides

Load Cell Sensitivity 101

Interface Force Measurement 101 Series Introduction

Extending Transducer Calibration Range by Extrapolation

Top Five Reasons Why Calibration Matters

Accurate Report on Calibration

Testing Lab Essentials Webinar

Interface experts detail standard measurement devices that are essential to all testing labs. They highlight calibration standards and calibration grade equipment, along with instrumentation and data acquisition systems. What types of equipment do you need in the lab to meet the testing demands of today and in the future? Watch this in-depth seminar for recommendations on equipment, best practices, tips, test lab applications and frequently asked questions.

Interface Force Measurement 101 Series Introduction

In our ongoing commitment to provide valuable resources through self-help guides and online reference materials, we are introducing our 101 Series.

This new online resource is an easy-to-use guide for load cell basics and force measurement topics. The series is a collection of content in various formats that detail subjects related to test and measurement.

Interface prioritizes helping our customers understand the inner workings of our expanding line of sensors, accessories, and instrumentation by creating guides, technical manuals, and solution applications for force measurement.

The Interface 101 Series will introduce you to relevant subjects about our products and how we can help you get the most accurate and reliable force data in the industry by using our solutions.

Our new 101 Series guide is an effortless way to navigate through high-level test and measurement topics. Each section of the new 101 Series includes a featured 101 IQ blog on a single subject, as well as quick links to videos, case studies, white papers, application notes, product information, technical specifications and more related to that subject.

The goal in creating the 101 Series is to provide a basic understanding on how our products are used for various test and measurement applications across all industries. The references are an effective way to learn about the broad depth of Interface products like our precision load cells, torque transducers, multi-axis sensors, calibration systems and instrumentation. We also provide relevant test and measurement content related to types of force measurement testing, components, systems, and materials used in engineering highly accurate measurement technologies.

There are thousands of references found throughout our site, like our design files for product engineers and digital instrumentation set-up videos for lab techs. It is our pledge to develop material that support our 35,000 products, as well as provide educational content like the 101 Series and our ForceLeaders Webinars you can watch on-demand.

Included below are the current 101 IQ Blogs you will find featured on the 101 Series online guide. We will add additional references to this 101 Series, as we post new subjects. Go to Force Measurement 101 Series to bookmark this reference.

101 Series IQ Blogs

You can find additional reference materials related to our products and services including manuals, product catalogs, technical references, and events.  Go to our online support to find helpful educational and advanced resources like our technical glossary, engineering tips and installation guides.

If you are mostly interested in why you should choose Interface, here is a good reference to start.

If you are not able to find the information you need or you have a specific question about our products or services, be sure to contact us to help.

Additional Interface Calibration Grade Solutions

As a leading supplier to testing labs around the world, Interface has designed specialized strain gage products that are classified as calibration grade. Our most popular calibration grade load cells are the 1600 Gold Standard LowProfile Load Cells and 1800 Platinum Standard model series. Both series provide tension and compression in one unit. These products are commonly used to calibrate and monitor test equipment, as well as to perform in-house calibrations.

What is not as widely known is that we offer more than our precision calibration grade load cells. We also offer an array of additional calibration grade products including instrumentation, torque sensors, accessories, adapters, and complete calibration systems.

Here are just a few examples of additional calibration grade products Interface offers.

9840 CALIBRATION GRADE MULTI-CHANNEL LOAD CELL INDICATOR

The 9840 indicator is suitable for use in calibration labs, field service, or anywhere high accuracy is important. This product’s features include a bipolar 6-digit 2-line display, remote sense, low noise, 24-bit internal resolution, USB port with RS232 communication, mV/V calibration, store calibrations for up to 25 sensors. It offers 6-point linearization, unit conversion and front-panel tare. This unit also has self-calibration via TEDS Plug and Play ready IEEE 1451.4 compliance.

5500 CALIBRATION GRADE REACTION TORQUE TRANSDUCER

The 5500 series is a flange-type calibration grade reaction torque transducer. Its rugged design offers low deflection, high torsional stiffness, and the ability to withstand large overhung moments. ASTM E2428 Calibrations are available on most capacities. There are multiple models available in this series.

DIGITAL CALIBRATION GRADE 4 CHANNEL 9840-400-1-T INTELLIGENT INDICATOR

The model 9840 intelligent digital indicator is frequently selected for calibration labs and as part of complete calibration systems. It features two interactive graphical touch screen displays, remote sense, low noise, 24-bit internal resolution, USB port with RS232 communication, mV/V calibration, store calibrations for up to 25 sensors.

IFVF CAPACITY FORCE VERIFICATION FRAME

The IFVF is a portable high force capacity frame and accessories that can be used be used to verify operation of a device under test or calibrate relative to a second reference load cell. It is designed to apply tension and compression forces with high resolution and accuracy. IFVF features a reaction frame, manual actuator, thread and adapter accessories, and optional force sensors and instrumentation.

CALIBRATION GRADE INTERFACE 2200 COLUMN LOAD CELL

This special lightweight column load cell model series is a tension and compression calibration ready design. It is portable for use in the field or in a lab.

Our Interface Load Cell Calibration Systems provide all the components for rigid and portable systems. Our strain gage load cell calibration systems are versatile and can be customized based on the application requirements.

Additional Resources

Interface Calibration 101

Calibration Grade Load Cells and Systems

Calibration Load Frame

Gold Standard® Calibration System

 

 

Engaging Interface Calibration and Repair Services Expertise

A high-quality load cell is a critical piece of technology for the design and testing of products throughout various, highly regulated industries including medical, aerospace and defense, automotive, and industrial automation. To get the most out of a load cell, just like anything else, you need to understand how to care for and maintain it. A poorly maintained load cell can lead to inaccurate data and poor performance.

Interface Calibration and Repair Services provide a valuable function for our customers in recalibration and technical support for the thousands of products manufactured by the leader in force measurement.  When cared for properly, a load cell should to be calibrated once a year or at least every two years under regular use. There are also certain circumstances where a load cell is damaged in use and needs immediate repair. Interface can handle calibration and repair of any load cell on the market, whether we build it or not.

A key differentiator for Interface is the fact that our calibration lab is ISO 17025 and A2LA accredited. These accreditations are typically for major calibration labs, not in a manufacturer’s facilities like ours. Our deep expertise in the development of load cells allows us to provide the highest quality calibration and repair services on the market because we know the product inside and out.

Interface’s Industry Leading Calibration and Repair Process

The Interface calibration team consists of 10 individuals dedicated to an optimized calibration and repair process that gets our customer’s load cells in and out as quickly as possible. The process begins with the front-end team, who manages the customer’s request, goes through the RMA process, and troubleshoots any additional concerns with the customer.

Once we review the product in-house at our Arizona headquarters, the load cell goes through a thorough inspection process to identify any necessary repairs and to ensure the load cell is in working condition for calibration. This includes an electrical test to evaluate if the load cell is in proper condition to calibrate. It’s also important to note that if the load cell can’t be repaired, there is no charge to the customer, and we work to find a replacement unit. The customer also approves any repairs that are necessary before work begins.

The final step in the process is the actual calibration. Our calibration team has many years of experience and know load cells inside and out. We also work with the most advanced equipment, including our proprietary Gold Standard® and Platinum Standard® systems. These devices ensure that the load cells are calibrated to the most accurate capability possible before returning to the customer. More information about Interface Calibration Systems can be found in our Calibration Systems 101 blog here.

Our commitment to building quality calibration systems is evident by the customers who also use them to do calibration in-house. In fact, in nearly every major manufacturing testing lab, you will find an Interface Gold Standard Calibration System and Gold or Platinum Standard Load Cells. This is because our customers are working on some of the most advanced hardware in their respective industries and fields. Engineers and testing labs trust Interface for accuracy, performance and quality.

Interface customers not only need to ensure their measurements are as accurate as possible to avoid product failure, they also need to prove the accuracy of their testing equipment for those products to pass inspection and make it to the market. We provide both our expert calibration services in our calibration lab, or through high-quality, high-reliability systems available that we build for our customers.

Interface Calibration and Repair Services

  • 50+ Years of Calibration Experience
  • Calibration of All Manufacturers Load Cells
  • 100,000+ Calibrations Performed Annually
  • Custom Calibrations
  • IPerform Service Software for RMA, Tracking and Permanent Archive of Test Data
  • NMI Certified Gold and Platinum Standard Reference Load Cells
  • Interface Gold Standard Calibration Software Used for Data Collection and Analysis
  • Full-Service Machine Shop for Mechanical Requirements

Force Capabilities:

  • NIST/NMI Traceable Calibration
  • 2 gf – 1 Million lbf Calibration Capability
  • (9) Hydraulic & (5) Deadweight Test Stands to Support Your Calibration Requirements

Torque Capabilities:

  • 0.022 – 100K in-lbf Capacities
  • NIST Traceable to 2.2K in-lbf
  • NMI Traceable 2.2K – 100K in-lbf

Interface calibration and repair services are designed with the customer in mind. Our process is fast, reliable and will ensure premium accuracy for our customer’s most complex and high-quality data-dependent design and test projects. Our team of experts work with every customer to ensure personalized world-class service.  It starts with engagement, how can we help?

For more information on Interface calibration and repair services, please visit /calibration-repair/.

Click here to schedule a service today.

Contributor:  Chris Brandenburg, Technical Services Manager at Interface

Calibration Grade Load Cells and Systems

The Interface brand has become synonymous with premium accuracy, reliability, and performance since we pioneered load cells back in 1968. Because of our reputation and commitment to quality, our Gold Standard® and Platinum Standard® Calibration Grade products are used by engineers and calibration experts in top metrology labs independently and within aerospace, automotive, medical, and industrial automation industries around the world.

Why Interface is the Gold Standard in Calibration Grade Load Cells?

Calibration grade load cells meet ASTM E74 standards, capable of 2% lower load limits. These Interface products are handcrafted in design and production for excellence in performance, meeting the most demanding calibration requirements. Accuracy is considered extremely high by precision standards.

One of the key reasons for our product’s accuracy is the fact that Interface leverages a vertically integrated design and production method. We control the entire manufacturing process, which begins with the development of our own strain gages.

Strain gages are the heart and soul of every load cell. By controlling the design and production, we can customize the strain gage in each load cell to fit the specific force measurement needs of our customers.

To develop our Gold and Platinum Standard products, the most accurate and reliable products in our catalog, we add more strain gages to improve performance and allow for a higher tolerance. We also run more intensive tests to ensure premium quality. These products are tested at 30 points and in three different positions to provide a coefficient. This coefficient allows us to use the Gold Standard Calibration Systems to get more precise performance and calibrate load cells against a more precise analysis. The final results lead to the most accurate and trusted calibration systems and calibration load cells.

Interface Calibration Systems and Load Cell Application

In nearly every major manufacturing lab in the U.S. and beyond, you will find an Interface Gold Standard Calibration System and Gold or Platinum Standard Load Cells. This is because our customers are working on some of the most advanced hardware in their respective industries and fields. These customers not only need to ensure their measurements are as accurate as possible to avoid product failure. They also need to prove the accuracy of their testing equipment for those products to pass inspection and make it to the market.

Interface Gold Standard Calibration Systems and Load Cells are used in a wide variety of applications. This includes wing and rocket tests to make sure the structural integrity of the hardware will hold up to extreme conditions and force. Our calibration systems are also used in stent stress testing to prove that an implanted stent will not fail over the lifetime of the patient. If they do, it can lead to serious medical complications and often death.

Interface Gold Standard and Platinum Calibration Grade Products

Our product line includes a wide range of Gold and Platinum Standard Load Cells and Gold Standard Calibration Systems. These products are uniquely suited for a wide number of applications and industries. Read how Interface Defines the Gold Standard in Calibration Systems here. The calibration grade products in this lineup include:

Calibration Grade Load Cells:

Calibration Systems:

For more information on Interface Gold and Platinum Standard Load Cells and Calibration Systems, contact our Application Engineers or visit www.interfaceforce.com.

Contributor: Ken Bishop, Sales and Custom Solutions Director, Interface

Calibration Systems 101

Even with the most accurate load cells available, the toll of constant use over long periods, and in some cases accidental misuse, can impact the reliability of the output. Calibration of force measurement products is vital in performance management, and necessary for safety and compliance with ISO and industry-specific standards.

In a recent Interface customer survey, 21% of respondents are calibrating load cells in-house. This is one of the reasons why Interface provides world-class load cell calibration solutions in several design configurations, as well as custom products, for a wide range of rigid and portable systems. Interface calibration offerings include complete systems for desktop and portable configurations, load frames, signal conditioning boards, intelligent digital indicators, calibration grade load cells, and calibration adapters.

The Interface Gold Standard® Calibration Systems, using the Interface Gold or Platinum Standard® Load Cells, ensures a metrology system of the highest accuracy and lowest uncertainty available.

The GS-SYS Gold Standard® Calibration System Load Frame consists of a four-post rigid load frame, proprietary load feedback loop, signal conditioning hardware, and fully-automated calibration software for the highest accuracy and lowest uncertainty available. Portable versions of the GS-SYS system are also available for calibrating load cells and test equipment.

Features of the system include:

  • 2 channels with an option available for 3 and 4 channels
  • 9840 Intelligent Indicator
  • Less than 0.04% RDG uncertainty
  • Testing and reporting per ASTM E74 and/or ISO 376 standards
  • Automated reports, graphs, and performance parameter calculations with custom reporting options
  • Innovative fixturing allows for tension and compression calibration without changing the setup
  • Proprietary load feedback design for accurate and reliable load control
  • Data archiving

A fully automated Interface Calibration System can reduce calibration time by 50% to 90% and can be set for automated calibration runs to be completed in less than five minutes.

The top calibration grade load cells from Interface are the 1800 Platinum Standard® Calibration Load Cell in ranges of 1.1K lbf to 55K lbf, 4.89 kN to 245 kN, followed by the 1600 Gold Standard® Calibration Load Cell with options from 500 lbf to 200K lbf and 2.22 kN to 900 kN.

Interface also has a compression-only calibration load cell, the 1601 Gold Standard®, in capacities of 1K lbf to 100K lbf and 4.45 kN to 445 kN.  The 1606 Gold Standard® Low Capacity Calibration load cell is also used in metrology labs, with products available in 50 lbf to 300 lbf ad 222 N to 1.33 kN sizes.

Interface also offers calibration software included with our calibration products. The ICS-202 Gold Standard® Load Cell Calibration Software will provide exact load output at specific load points. Calibration results from other runs can be compared, measured, and displayed with current run results.

Interface provides the most accurate and reliable load cells in the force measurement industry. We are able to do this because we control the entire load cell development process from design to production, including manufacturing our own strain gauges. Controlling the complete process ensures outstanding product quality which is confirmed through our stringent calibration requirements before any Interface product is shipped to our customer.

Interface load cells are capable of lasting a very long time. In fact, we recently received a calibration service request on some of the very first load cells that we have ever manufactured, decades old. To ensure load cells last as long as possible, Interface recommends customers calibrating their load cells on an annual basis. The frequency of calibrations should also be determined by the following factors:

  • Measurement quality and allowable tolerance range
  • Subjected level of stress on the equipment
  • Stability of past calibrations
  • Required measuring accuracy
  • Quality assurance requirements

Whether you rely on Interface for calibration maintenance services or perform the services in-house, we have calibration solutions to meet your exact needs including load frames, signal conditioning boards, and intelligent digital indicators.  Contact our specialized Application Engineers to discuss the best options for your requirements.

Download or view the Calibration Systems Brochure

Contributor:  Jay Bradley, Sr. Electrical Engineer, Interface

Interface Defines the Gold Standard in Calibration Systems

Interface understands that when companies are designing and testing complex structures like airplanes, space shuttles, automobiles, and oil & gas rigs, failure is not an option. In order to reduce uncertainty and guarantee the safety of these systems, the highest levels of accuracy in the testing process is an absolute requirement before any structure is moved to final production.

For more than a half-century, Interface has set the standard for reliability in force measurement products. Each load cell that leaves our doors is precisely calibrated to the highest standards available on the market.

In fact, we are maintaining standards of accuracy acceptable by the world’s leaders in aerospace, energy, rockets, medical devices, infrastructure, automobiles and more. Assurance of accuracy and quality are supported through our proprietary Gold Standard® Calibration System, which is the defining ‘gold standard’ in our industry.

Years ago, our customers started asking how we could help them do an in-house calibration. We knew we had to ensure the same quality we used ourselves, no exceptions. So we built our system for commercial use, making it the first of its kind calibration system available to our valued load cell customers.

Interface is the only major load cell company that also sells calibration systems. In fact, many calibration labs and other load cell makers calibrate their load cells with Interface Gold Standard Calibration Systems.

GS-SYS Gold Standard Calibration System Load Frame

GS-SYS Gold Standard Calibration System Load Frame

Interface Load Cell Calibration Systems are available for a wide range of rigid and portable systems and configurations. The Interface GS-SYS Gold Standard® Calibration System Load Frame uses the Interface Gold Standard® Load Cell to ensure a metrology system of the highest accuracy and lowest uncertainty available. It consists of a four-post rigid load frame, proprietary load feedback loop, signal conditioning hardware, and fully-automated calibration software. It also comes in a desktop and portable system for more effortless mobility.

Additional features of the Interface Gold Standard® Calibration System include:

  • 2 channels (options available for up to 8 total channels)
  • SCB1 measurement board featuring <0.003% FS Nonlinearity
  • Less than 0.04% RDG uncertainty
  • The fully-automated system will reduce calibration time by 50% to 90%
  • Automated calibration run can be completed in less than 5 minutes
  • Innovative fixturing allows for tension and compression calibration without changing the setup
  • 12 in. clearance between posts allows for easy load cell installation and removal
  • Accurate and reliable load control achieved by proprietary load feedback design
  • Testing and reporting per ASTM E74 and/or ISO 376 standards
  • Automatically produces standard reports, graphs, and performance parameter calculations
  • Ability to customize reports and graphs
  • Automatically archives data

We also offer training on our systems for new users.  There are additional features that can be customized into calibration systems.  Contact our expert customer solutions application engineers here.

The Gold Standard Calibration System is the preferred choice for companies that value accuracy and reliability. If you prefer that Interface does all your calibration and repairs, contact our trusted service and cal experts today at /calibration-repair/.

 

 

Present and Future Interface Calibration Product Family

Calibration of force measurement tools is integral to accuracy and success in product design and development. As a follow-up to our feature on our expert calibration services, here is a quick introduction to some of our current and future calibration products.

The calibration product family includes five calibration systems that are designed for various needs and force measurement parameters. These systems include:

  • 55K lbf and 110K lbf Automated Calibration System and 2K lbf Automated Calibration System
  • 2K lbf Load Cell Verification System
  • Next Gen High-Resolution Signal Conditioning Board (HRSBSC)
  • 4 Channel 9840-400-1-T Intelligent Indicator

55K lbf and 110K lbf Automated Calibration System and 2K lbf Automated Calibration System

The 55K lbf and 110K lbf Automated Calibration Systems are Interface’s most popular systems because two capacities represent the two most popular capacities requested by customers.

“These systems allow customers to speed up their calibration process because rather than outsourcing calibration, it can all be done in-house.”  Ted Larson, VP of Product Development

The systems are unique in the industry because unlike competitor products, they feature a fully automated system that can measure both tension and compression in a single setup. These systems are designed to satisfy the calibration needs of the test and instrumentation, automotive, aerospace and metrology industries.

The 2K lbf Automated Calibration System, which is on track for release in Q2 of 2019, will offer the same level of accuracy, consistency and excellence as the 55K lbf and110K lbf Systems, but is designed for low-end capacity load cells. This system will serve as a bench top unit and integrate with the same software as the 55K lbf and 110K lbf Systems. It is being designed to serve the medical and automation industries.

The 2K lbf, 55K lbf and 110K lbf Systems will be able to be integrated to work as a dual range system for customers who need to calibrate a wide range of load cells.  Both systems utilize our industry-leading gold and platinum standard load cells, which provide the highest accuracy in the industry.

2K lbf Load Cell Verification System

The 2K lbf Load Cell Verification System is another calibration product that is on track for a Q2 2019 release. This system is being designed as a direct response to OEMs who deal with large volumes of load cells and need a quick, low-cost way of verifying load cells used in equipment. Currently, customers who suspect a calibration issue are often forced to remove load cells from equipment and be sent in to be repaired, recalibrated or to receive a new load cell. This process and the resulting downtime costs money due to lack of production, and there is often no issue present with the load cells.

The 2k lbf Load Cell Verification System can identify a calibration or performance issue, allowing the customer to accurately determine if the load cells need to be replaced or need a tune-up, significantly reducing unnecessary downtime.

Next-Gen High-Resolution Signal Conditioning Board (HRSBSC)

The High-Resolution Signal Conditioning Board, which Interface pioneered more than three decades ago, will be receiving an innovation update to improve performance and capabilities. The HRSBSC is designed for use with Interface Gold Standard Calibration Systems and can be provided in a single or dual channel solution. This product’s primary industries include test and instrumentation and metrology. The development of Interface’s Next-Gen HRSBSC is slated for Q4 of 2019.

4 Channel 9840-400-1-T Intelligent Indicator 

Interface recently introduced a new version of the 4 Channel Model T which features a more modern display with additional channels available. It’s now easier to use and has the same high stability and industry-leading performance as the older version of the 9840. Although the quality is the same, the updated version can be integrated with Interface’s Gold Standard® system and frames, as well as with Windows 10.

The 4 Channel Model T 9840-400-1-T Intelligent Indicator allows single loads with three measurements to directly compare outputs to Interface’s Gold Standard load cell, and all measurements can be captured through Interface’s Gold Standard software. This allows users to compare multiple load cells and gather data on whether the load cells are accurate or uncalibrated. The 4 Channel Model T solution also has the option for high-level input channels.

Stay tuned for updates on current and upcoming additions to our family of innovative calibration products.

Contributor: Ted Larson, VP of Product Development and Marketing, Interface