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Signal Conditioners 101

Signal conditioners are used in instrumentation, control systems, and measurement systems where accurate and reliable signal processing is a requirement. The purpose of a signal conditioner is to ensure that the electrical signal from a sensor is compatible with the input requirements of the subsequent signal processing equipment.

Primary features of signal conditioners include amplification, filtering, isolation, and linearization. It can perform various functions depending on the specific application and the type of signals.

Interface Signal Conditioners are used with a wide range of load cell and force measurement devices. Transducers convert force or weight into an electrical signal. The output signal of a load cell is typically in the form of a small electrical voltage that is proportional to the applied force.

Be sure to reference the Instrumentation Selection Guide to find instrumentation with signal conditioners that will best fit your force measurement application.

Understanding Signal Conditioners Use with Load Cells

Amplification: Load cells produce small electrical signals, which may require amplification to bring them to a usable level. Signal conditioners can include built-in amplifiers that increase the magnitude of the load cell signal. This amplification helps to improve the signal-to-noise ratio and enhances the sensitivity of the system.

Filtering: Load cell signals can be affected by electrical noise or interference, which can degrade the accuracy of measurements. Signal conditioners often incorporate filtering capabilities to remove unwanted noise and interference from the load cell signal. This ensures that the signal is clean and reliable.

Excitation: Load cells require an excitation voltage or current to function properly. Signal conditioners provide a stable and regulated excitation source to power the load cell. This excitation voltage is typically supplied to the load cell through the signal conditioner, ensuring consistent and accurate measurements.

Calibration and Linearization: Load cells may exhibit nonlinear characteristics, meaning that the relationship between the applied force and the output voltage is not perfectly linear. Signal conditioners can include calibration and linearization algorithms to compensate for these nonlinearities. By applying appropriate mathematical adjustments, the signal conditioner can provide a linear output that accurately represents the applied force.

Signal Conversion: Load cell signals are typically analog voltages, but they may need to be converted to digital format for further processing or transmission. Some signal conditioners include analog-to-digital converters (ADCs) that convert the analog load cell signal into digital data, enabling it to be processed by digital systems.

Signal Conditioner Considerations

  • Form factor design: box mount, DIN rail, in-line cable, integral to load cell
  • Output options: ±5/±10VDC, 0.1-5VDC, Current, Frequency, Digital
  • Polarity: Bi-polar or unipolar
  • Bandwidth
  • Onboard filtering
  • Power supply type: cable, built-in, wireless
  • Noise immunity

Interface Top Signal Conditioners

PRODUCT: DMA2 DIN RAIL MOUNT SIGNAL CONDITIONER

  • User selectable analog output +/-10V, +/-5V, 4-20mA
  • 10-28 VDC power
  • Selectable full scale input ranges 5-50mV
  • DIN rail mountable
  • Push button shunt calibration
  • 1000Hz bandwidth

PRODUCT: SGA AC/DC POWERED SIGNAL CONDITIONER

  • User selectable analog output +/-10V, +/-5V, 0-5V, 0-20mA, 4-20mA
  • 110VAC, 220VAC, OR 18-24VDC power
  • Switch selectable filtering 1Hz to 5kHz
  • Single channel powers up to four transducers
  • Selectable full scale input range .06 to 30mV/V
  • Sealed ABS enclosure
  • Optional bridge completion and remote shunt activation module

PRODUCT: ISG ISOLATED DIN RAIL MOUNT SIGNAL CONDITIONER

  • Galvanically isolated power supply
  • High accuracy
  • +/-5VDC or +/-10VDC Analog output (4-20mA optional)
  • 10-30VDC Power
  • Switch selectable filtering 1Hz to 1kHz (up to 10kHz optional)
  • Accepts inputs up to 4.5mV/V
  • DIN rail mountable

CSC and LCSC-OEM Inline Signal ConditionersPRODUCT: CSC and LCSC-OEM INLINE SIGNAL CONDITIONERS

  • IP67 stainless steel enclosure (CSC Only)
  • CE approved (CSC Only)
  • Zero and span adjustments
  • 1 kHz bandwidth

PRODUCT: VSC2 Rugged Compact Vehicle Powered Signal Conditioner

  • High accuracy precision bi-polar differential amplifier
  • ± 5 VDC Output
  • Accepts inputs from ±1.4 to ±-4.2
  • 1000 Hz low pass filter
  • Rugged design and compact size
  • Course, fine zero, and span adjustments
  • Activate R-CAL (Shunt Cal) with internal switch

Signal conditioners ensure that the load cell’s output is optimized for accuracy, stability, and compatibility with the measurement or control system. They help mitigate noise, amplify weak signals, provide excitation, and perform calibration and linearization to ensure precise and reliable measurements of force or weight.

Visit the Interface Instrumentation Selection Guide to see all the products available with signal conditioning functionality.

Watch this Testing Lab Essentials Webinar Part 3 to learn more about the benefits and use cases of Interface Signal Conditioners.

Interface OEM Solutions Process

Engaging with Interface to create a solution uniquely designed for your specific application, at scale, requires a proven process that is trusted and reliable.  Interface works with manufacturers across all types of industries, from medical to energy, to supply custom-made sensors to are used to activate components, provide measured feedback in products, for safety requirements and monitor performance. When accuracy, quality and reliability matter, Interface is a partner of choice for OEM Solutions.

In partnership with integrators and original equipment manufacturers, we fully support four phases in our OEM Solutions Process: Design, Test, Build and Supply. The OEM Process infographic highlights high-level activities in each phase.

OEM Process

The Process for OEM Solutions at Interface

#1 DESIGN PHASE:  Collaborating with our team of OEM experts begins at the design phase. We work together with you providing engineering support and mechanical sensor design expertise as we work together to scope out the requirements and create design drawings. It is important to connect early to ensure you have captured all the important details that are relevant to embedding sensor technologies into products. Beyond size and capacity, you will want to determine what you will measure, how it will transmit data and frequency of communications, as well as exact sensor type, material use and configurations. Do you need a miniature load cell or multi-axis sensor capabilities? Will it be a load button, S-Type or load pin that fits your specs? These are the types of questions we address in the early stages of the design process. To complete this phase, we provide prototypes of early designs and also pricing based on scale of production and timelines for delivery.

#2 TEST PHASE: The second phase of the OEM process involves a complete testing protocol, selecting materials and supplies as well as packaging requirements.  For example, do you need a sealed solution, coated, stainless? We work to define exact specifications of the sensor based on performance and producibility. We work closely with our engineering, production and calibration teams through test and simulations.

#3 BUILD PHASE: Upon customer approval, once testing and prototypes are given the green light, we move to producing the devices at scale. Building requires an orchestrated team that is dedicated to quality and precision in the build process.  We measure and track each required step in the build phase with exactness, allowing for no exceptions or error. We set schedules, define the floor plans and build the instructions to build based on your requirements. These critical steps ensure the parts are built and delivered within your scheduled requirements and our quality standards.

#4 SUPPLY PHASE:  Interface acts as your supply chain partner in the management of production, stock and delivery. We work closely with you in inventory management and forecasting. This is where our partnership is heavily dependent on ongoing communications and reporting to project, produce and ship your parts when you need them.

In our recent webinar, Embedding Sensors in Products, our team highlights the steps, actions and commitment to getting you the solution you need. You can watch the recorded event here. Get a copy of our OEM Solutions brochure to learn more. Contact our specialized OEM Solutions Team today to get started by letting us know how we can partner with you for Interface OEM products and services.

Additional Resources:

OEM Solutions- Turning an Active Component into a Sensor

OEM: Medical Bag Weighing

OEM: Snack Weighing and Packaging Machine

OEM Industrial Robotic Arm App Note

Embedding Sensors in Products Webinar Recap

Interface recently hosted a live virtual event, Embedding Sensors in Products, where Brian Peters and Randy White detail the processes, products and uses cases for using Interface load cells, load pins, and torque transducers as a stand-alone sensor solution or a component within a product.

Interface has been providing custom engineered and manufactured solutions for more than 50 years to equipment manufacturers (OEMs) and product engineers to meet unique specifications and requirements.

Interface sensor technologies are frequently being used medical devices, machines and equipment, industrial automation robotics, material extraction and pumps, weighing and monitoring devices, vehicle production and components and more. Building any custom OEM solution to exact specifications is a team sport.  Working together with Interface engineers, we partner with the customer through ever stage: Design, Test, Build and Supply.

The typical uses cases for Interface OEM Solutions include:

  • Products requiring sensor technology components
  • Instrumenting components
  • Utilizing sensors to measure force, weight, or torque
  • Managing test and measurement processes and protocols
  • Precision performance requirements and testing 

The entire recorded Embedding Sensors Event is available to online to watch at your convenience.

The best tip for success is to engage early with Interface. Our experts have the experience and know-how of product capabilities, applications, configurations, and a history of what works and potential risks. When getting started, details matter. Our OEM Applications Engineers will work with you to ensure we have answer to important questions, including: 

  • What are you measuring?
  • Why are you measuring?
  • What signal or connectivity is needed?
  • Measurement range and potential loading conditions
  • Envelope and mechanical integration
  • Environment
  • Calibration – relative vs absolute measurement
  • What are you trying to solve #1?

Be sure to watch the new ForceLeaders event to gain insights into the process, tips for success, industry use cases and the range of products available for embedding sensors into products. There are many products Interface has available that are great options for engineered-to-order and customization. These Interface products include low and high capacity load cells, compression load cells, miniature load cells and load buttons, load pins, s-type and beam load cells, sealed load cells, torque transducers, digital communication devices, multi-axis sensors and more. Several product options are discussed in detail during this informative presentation

You can watch the presentation below, where our experts discuss the following topics:

  • Interface OEM Solutions
  • How to Get Started
  • Dialing in on Specifications and Requirements
  • Process: Design, Test, Build and Supply
  • Common Sensors Used for OEM
  • Trends in OEM 
  • Applications + Uses Cases
  • FAQs

If you have questions about how to get started or need further information about our OEM Solutions, go here. Our experts are ready to help with your exact requirements.  Additional information is also available in our white paper, New Interface White Paper Highlights Turning an Active Component into a Sensor.

Faces of Interface Featuring Richard Snelson

Richard Snelson, president of Measurements Incorporated, is the leader of our outstanding manufacturers’ representative firm serving the Mid-Atlantic coast of the US. The origin of the company, that supports customers in this region with application solutions for structural, material, and environmental testing, is an intriguing story.

In this new Faces of Interface feature, Richard highlights one of his favorite projects and provides his thoughts on representing the most reliable and accurate force measurement products in the industry from Interface.

Richard grew up in Philadelphia, Pennsylvania, and was brought up hearing all about his ‘old man’ and the incredible work he got to do with customers across the technology landscape. His father and two partners started Measurements Incorporated in 1976. The company had spun out of another company called Micro Measurements. At that time, they sold a limited range of product lines to a wide range of customers. Some of the most memorable customers Richard would hear about from his dad included those that worked with bridges, battle tanks and even cadavers.

After high school, Richard attended Indiana University of Pennsylvania, where he would go on to earn a split degree in business, marketing, and management. During his college years, Richard also received a ton of career experience working multiple jobs. His summers were spent as a technician in the Princeton Plasma Physics Lab, where his role include working on a reactor. He also worked on the Brooklyn Bridge, replacing cables on the massive structure, as well as working for a friend of his dad in the oil and gas industry. These jobs not only put Richard through college, but they also exposed him to hands-on experience working with organizations and on projects like what his dad would talk about at home when he was growing up.

The experiences and incredible stories he was told throughout his youth pushed Richard to accept a role working for his father’s company. He started out selling one product line, XY plotters, to major test labs and facilities across the Mid-Atlantic. After finding a great deal of success, Richard was given the entire state of Delaware to sell every product line in the company’s portfolio. This eventually expanded into Pennsylvania and Maryland.

As he grew his expertise as a sales rep at Measurements Incorporated, Richard also began buying out the other two owners as they retired and eventually retained sole ownership of the company in 2003. Today the company carries an ever-expanding product line of test and measurement equipment and serves some of the most reputable organizations across multiple industries including, aerospace, defense, medical, industrial, and more.

I put myself in the customer’s place and offer a complete solution, sometimes reminding them of things they might not initially think of and the end result is that we are all successful.” Richard Snelson, president of Measurements, Incorporated.

Like his father, Richard has also collected many of his own fun, interesting, and sometimes incredibly nerve-racking stories. Among his favorite are the two times he was asked to head over to One World Trade Center to oversee installation equipment and then later assess a challenge with a sensor on the building’s enormous spire on the very top. Richard and few other men from the company charged with some of the tower’s maintenance and caretaking went up to the top together. During the assessment, Richard and the maintenance company’s president were tasked with repelling up the spire to identify and fix the sensor. Richard enjoyed an unforgettable experience and got a sweat-inducing picture in the process that you can see in his photo above!

Richard has a long-time relationship with Interface that began in 2006. He raves about the quality of the brand and the confidence he and his customers have in the accuracy and reliability of our force measurement sensors. He has great respect for the people he works with regularly, including his Regional Sales Director, Elliot Speidell. Richard often finds himself identifying the signature blue paint job on our load sensors during customer facility tours. He’s proud that he’s able to offer the industry’s leading force measurement solutions to some of the world’s most prominent organizations.

When he’s not dangling off one of the tallest buildings in the world or helping solve key customer challenges with a bevy of critical instrumentation, Richard enjoys time spent with family, his wife of 36 years Tracey, their two children Courtney and Derek, and their grandson Everett. The family loves to spend their time outdoors and can often be found sailing on the Chesapeake Bay.  Richard also enjoys recreational shooting and cruising around on his motorcycle.

We couldn’t have asked for a better partner in Richard and his team at Measurements Incorporated. We are happy to share his story. Looking for more Faces of Interfaces? Go check out our ForceLeaders here.

 

Load Cell Test Protocols and Calibrations

In the Interface Load Cell Field Guide, our engineers and product design experts detail important troubleshooting tips and best practices to help test and measurement professionals understand the intricacies of load cells and applications for force measurement devices. In this post, our team has outlined some helpful advice for testing protocols, error sourcing and calibrations.

The first step in creating test protocols and calibration use cases is to define the mode you are testing. Load cells are routinely conditioned in either tension or compression mode and then calibrated. If a calibration in the opposite mode is also required, the cell is first conditioned in that mode prior to the second calibration. The calibration data reflects the operation of the cell only when it is conditioned in the mode in question.

For this reason, it is important that the test protocol, which is the sequence of the load applications, must be planned before any determination of possible error sources can begin. In most instances, a specification of acceptance must be devised to ensure that the requirements of the load cell user are met.

Typical error sources in force test and measurement are usually identified as being related to:

  • Lack of protocol
  • Replication of actual use case
  • Conditioning
  • Alignment
  • Adapters
  • Cables
  • Instrumentation
  • Threads and loading
  • Temperature
  • Excitation voltage
  • Bolting
  • Materials

In very stringent applications, users generally can correct test data for nonlinearity of the load cell, removing a substantial amount of the total error.  If this can’t be done, nonlinearity will be part of the error budget.

An error budget is the maximum amount of time that a technical system can fail without service level consequences. In force test and measurement, it is sometimes referred to as uncertainty budget.

Nonlinearity is the algebraic difference between output at a specific load and the corresponding point on the straight line drawn between minimum load and maximum load.

Nonrepeatability is essentially a function of the resolution and stability of the signal conditioning electronics.  Load cells typically have nonrepeatability that is better than the load frames, fixtures and electronics used to measure it.

Nonrepeatabillty is the maximum difference between output readings for repeating loading under identical loading and environmental conditions.

The remaining source of error, hysteresis, is highly dependent on the load sequence test protocol.  It is possible to optimize the test protocol in most cases, to minimize the introduction of unwanted hysteresis into the measurements.

Hysteresis is the algebraic differences between output at a given load descending from maximum load and output at the same load ascending from minimum load.

There are cases when users are constrained, either by requirement or product specification, to operate a load cell in an undefined way that will result in unknown hysteresis effects. In such instances, the user will have to accept the worst-case hysteresis as an operating specification.

Some load cells must be operated in both tension and compression mode during their normal use cycle, without the ability to recondition the cell before changing modes. This results in a condition called toggle, a non-return to zero after looping through both modes. The magnitude of toggle is a broad range. There are several solutions to the toggle problem, including using a higher capacity load cell so that it can operate over a smaller range of its capacity, use a cell made from a lower toggle material or require a tighter specification.

ONLINE RESOURCE: INTERFACE TECHNICAL INFORMATION

For questions about testing protocols, conditioning, or calibration, contact our technical experts. If you need calibration services, we are here and ready to help.  Click here to request a calibration or repair service today.

Introducing Interface’s Upgraded 4 Channel Intelligent Indicator

Interface has been leading the way in force measurement innovation for the last 50 years, and over the course of our history, we’ve been consistently developing and improving upon our solutions.

A perfect example of this focus on continuous improvements and innovation is seen with our 4 Channel Intelligent Calibration Grade Indicator Model 9840-400-1-T. This solution is ideal for anyone who needs to calibrate a load cell with a single, double or triple bridge. And it just got some impressive new upgrades.

The new version of the 9840-400-1-T Intelligent Indicator features a more modern digital display with additional channels available. It’s now easier to use, with the same high stability and industry-leading performance as the older version of the 9840. Although the quality is the same as our older version, the update can be easily integrated with Interface’s Gold Standard® system and frames, as well as with Microsoft’s Windows® 10.

Interface’s 4 Channel Model 9840-400-1-T 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 out of calibration. The 4 Channel Model 9840-400-1-T solution also has the option for high-level input channels.

The Model 9840 is already being used in more than 300 labs, most of which have highly-specific metrology requirements.

‘It is the choice for many aerospace and metrology labs that do in-house calibrations because of its reputation as one of the most accurate calibration tools on the market.” Ken Bishop, Director of Sales Engineering, Interface

Other industries that have expressed great satisfaction with the Model 9840 [user_id], including those in test and measurement and automotive.

The 4 Channel 9840-400-1-T features include two Interactive 7″ 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. 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.

For anyone in need of a metrology-grade digital intelligent 4 channel solutions for high-end readings, Interface has the answer. To learn more, visit 4 Channel 9840-400-1-T or call 480-948-5555 to speak to our application engineers.