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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.

Shunt Calibration 101

Calibration is a critical stage to ensure proper accuracy and reliability of any force measurement device. There are many ways to calibrate and different types of calibration. In the standards of maintaining our quality and precision requirements, Interface calibrates every test measurement device we manufacture including our load cells and torque transducers. Every device is shipped with the most detailed calibration certifications in the industry.

With our experience and expertise, we understand that sharing what we know is beneficial to our customers and partners in the test and measurement industry. One of the means by which we do this is through a series of technical white papers.  A popular white paper that was written years ago still stands the test of time, as it provides a deep dive on the topic of shunt calibration. Click on the title “Shunt Calibration for Dummies,” to access the full white paper.

What is Shunt Calibration?

Shunt calibration is a technique for simulating strain in a piezo-resistive strain gage Wheatstone bridge circuit by shunting one leg of the bridge. The bridge may be internal to a discreet transducer or composed of separately applied strain gages. The resulting bridge output is useful for calibrating or scaling instrumentation. Such instrumentation includes digital indicators, amplifiers, signal conditioners, A/D converters, PLC’s, and data acquisition equipment. Care must be taken to understand the circuits and connections, including extension cables, in order to avoid measurement errors.

Benefits of Shunt Calibration

The biggest reason to use shunt calibration is the flexibility and low-cost it offers the user. In this method of calibration, the bridge circuit is already there, and you don’t need to make and break cable connections to run it. This means that a shunt calibration can be applied conveniently and at any time during the test program. It is often used in situations where the user is calibrating control system equipment that will be communicating with a transducer or to confirm that the transducer is functioning properly.

Expected Shunt Calibration Repeatability in Modern Transducers

An important question that comes up regarding calibration is what type of repeatability can I expect from shunt calibration? Included below are the specifications outlining expected repeatability:

Procedure for a repeatability test performed:

  • 100 Klbf Load Cell specimen loaded in compression.
  • 12 test cycles of 4 mV/V hydraulically applied physical load and 1 mV/V Shunt Cal on two bridge legs.
  • Rb = 350 ohm, Rs = 88750 ohm, 20 ppm/°C, internal to load cell.
  • Measurements over 3 days.
  • Interface Gold Standard HRBSC instrumentation.

Results of test

  • Std Dev of physical load measurement: 0.004%.
  • Std Dev of Shunt Cal: 0.001% pos, 0.001% neg.

The topics that are illustrated in examples and discussion points for this white paper include:

  • Basic Bridge Circuit and Formulas
  • Resistor Examples
  • Tolerance
  • Cables
  • Errors
  • Permanent Zero Balance Shifts
  • Transducer Toggles
  • Instrumentation
  • Procedures for Repeatability in Tests

If this is a topic that of interest, download this technical reference guide for further exploration and calculation examples in shunt calibration.

As a leader in calibration services, Interface has an A2LA ISO 17025 accredited calibration lab located at the company’s headquarters in Arizona. Many depend on Interface for expert recalibration, which we recommend to do annually for optima maintenance. Our own calibration lab has the broadest capability and highest quality of calibration and repair services available. We understand the criticality of proper calibration and traceability and have the experience and expertise necessary to meet your exacting needs.

Additional Calibration Resources

Extending Transducer Calibration Range by Extrapolation

Additional Interface Calibration Grade Solutions

Gold Standard® Calibration System

This refreshed white paper is a tribute to the contributions of LaVar Clegg.

Interface White Paper Highlights Contributing Factors to Load Cell Accuracy

Core to everything we do at Interface is within our foundational pillars of quality, service, accuracy, and innovation.

When it comes to precision load cells, our team of experienced engineers is fully committed to designing and building the best force measurement products in the industry. In fact, it is commonly known that with our published specifications, we often exceed them. It is why Interface products retain the industry-leading reputation for precision performance.

With innovation and imagination in our values, Interface team members look for ways to continuously test boundaries and explore possibilities, never losing sight of accuracy. We are students of the industry and understand the precise details and mechanics that go into force measurement product development to make our solutions are the most accurate on the market.

Critical to serving our customers is understanding the contributing factors of load cell accuracy and matching the products that best fit their requirements. There are many factors that can disrupt accuracy or skew data, such as the environment in which the load cell is being used, the type of load cell application use, even the mounting process.

All of these specifications must be correctly identified when choosing the right product for the project or product to ensure accurate results. To help our fellow community of engineers, manufacturers, and product designers to navigate the force measurement world, we have developed a new Contributing Factors to Load Cell Accuracy White Paper. Click here to get your copy today!

This Interface technical white paper includes a breakdown of the most critical factors of load cell accuracy, which includes:

  • Creep
  • Side and eccentric load
  • Temperature
  • Humidity
  • Mounting process

Chief Engineer Ken Vining provides valuable insights into some of the steps to take to avoid accuracy failure, such as:

  • Utilizing a golden part
  • Preventing load cell misuse
  • Setting a preventative maintenance schedule
  • Recalibration

This valuable resource provides a quick reference to understand load cells and the intricate details that come with their proper and accurate use. Included below is a link to access the downloadable PDF of the white paper. This technical white paper is an addition to our long-standing commitment to providing expert resources for those using or researching use case applications for load cells.

CLICK HERE TO ACCESS TO THIS NEW WHITEPAPER TODAY

The Interface Load Cell Field Guide is also available on Amazon.