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Interface Supports Wind Tunnel Testing

In the development of an airborne vehicle, like a plane or helicopter, wind tunnel systems are used to gather data across a variety of tests related to the aerodynamics of the vehicle’s design. Whether an object is stationary or mobile, wind tunnels provide insight into the effects of air as it moves over or around the test model. Interface is a supplier of measurement solutions used for aircraft and wind tunnel testing.

Wind tunnels are chambers that test small scale model versions of full systems, or in some cases, parts and components, depending on the size and capabilities of the wind tunnel. They work by allowing the engineers to control airflow within the tunnel and simulate the types of wind force that airplanes and other aircraft will experience in flight. Wind tunnels are also used for testing automobiles, bicycles, drones and space vehicles.

By taking careful measurements of the forces on the model, the engineer can predict the forces on the full-scale aircraft. And by using special diagnostic techniques, the engineer can better understand and improve the performance of the aircraft.

The process for measuring the force and how it reacts to this force works by mounting the model in the wind tunnel on a force balance or test stand. The output is a signal that is related to the forces and moments on the model. Balances can be used to measure both the lift and drag forces. The balance must be calibrated against a known value of the force before, and sometimes during, the test.

Interface’s strain gage load cells are commonly used in wind tunnel testing due to their quality, accuracy and reliability. The instrumentation requirements often depend on the application and type of test. The range of options for both load cells and instrumentation vary based on scale, use, cycle counts, and data requirements.

Instrumentation used in wind tunnel testing can be as simple as our 9325 Portable Sensor Display to a multi-channel data acquisition system. Interface analog, digital and wireless instrumentation solutions provide a range of possibilities. As is the case, wind tunnel testing is typically very sensitive. It is important to calibrate the instrumentation before each test to measurement accuracy.

Types of Wind Tunnel Tests Using Force Measurement Solutions

  • Lift and drag: Load cells are used to measure the two most significant forces that impact aircraft design. Lift is the force that acts perpendicular to the direction of airflow and keeps the craft airborne. Drag is the force that acts parallel to the direction of airflow and opposes forward motion.
  • Side force: This force acts perpendicular to both the direction of airflow and the lift force. It is caused by the difference in pressure between the upper and lower surfaces of the aircraft.
  • Moments: Moments are the forces that act around a point. The most common moments measured in wind tunnels are the pitching moment, the yawing moment, and the rolling moment.
  • Stability and control: Tests conducted to measure the stability and controllability of an aircraft are commonly using force measurement solutions for aircraft design changes or integrating new parts into an existing model.
  • Performance: Particularly important with new designs, engineers use these tests to measure the simulated flight performance under maximum speed, range and fuel efficiency.

The specific tests that are conducted in a wind tunnel depend on the project requirements.

Multi-Axis Sensors for Wind Tunnel Testing Applications

In measuring the forces of a wind tunnel test, multi-axis sensors offer the perfect solution for collecting as much data as possible across every axis, giving the engineer a more complete picture on the aerodynamics of the plane. In fact, Interface has supplied multi-axis load cells for use in several wind tunnel testing applications, for OEMs, testing facilities and part makers.

We offer a variety of multi-axis options including 2, 3 and 6-axis standard and high-capacity configurations depending on testing and data requirements of the user. These sensors can precisely measure the applied force from one direction with little or no crosstalk from the force or moment. Interface products provide excellent performance and accuracy in force and torque measurement.

To match the demands of the volumes of data available using multi-axis sensors in wind tunnel testing, Interface often provides several data acquisition instrumentation solution along with our BlueDAQ software.

Wind Tunnel Test Application

A major aerospace company was developing a new airplane and needed to test their scaled model for aerodynamics in a wind tunnel, by measuring loads created by lift and drag. Interface Model 6A154 6-Axis Load Cell was mounted in the floor of the wind tunnel and connected to the scaled model by a stalk. The wind tunnel blew air over the scaled model creating lift and drag, which was measured and compared to the theoretical airplane models. The output of the 6-axis sensor was connected to the BX8-AS Interface BlueDAQ Series Data Acquisition System, which was connected via USB cable to a computer. Using this solution, the company was able to analyze the collected data and made the necessary adjustments in their design to improve the aerodynamics of their theoretical airplane models.

Interface supports wind tunnel testing and all uses of force measurement in the advancements in aeropspace.

Wind tunnel testing is critical to the aircraft industry, as well as other industries like automotive and space. Interface has been providing multi-axis sensors and strain gage load cells to industry leaders and wind tunnel operators. We understand the unique needs of this type of testing and the instrumentation options that work best with our high-accuracy sensors. We also can work to provide custom solutions, load cells for use in extreme environmental conditions. Contact us to get the right solution for your specific testing program.

Additional Resources

Aircraft Wing Fatigue App Note

Airplane Jacking System

Interface Airplane Static Testing Case Study

Taking Flight with Interface Solutions for Aircraft Testing

Aircraft Yoke Torque Measurement

Aircraft Screwdriver Fastening Control App Note

Interface’s Crucial Role in Vehicle and Urban Mobility Markets

Rigging Engineers Choose Interface Measurement Solutions

 

Unlocking the Power of DAQ Webinar Recap

Interface hosted a technical seminar on the topic of data acquisition systems. With the demands for more data and faster processing with requirements to connect multiple devices in testing environments, there is an increasing need for high accuracy DAQ systems. Keith Skidmore and Dave Reardon detail the basics of DAQ, trends, products, software options and answer to questions in the webinar, Unlocking the Power of DAQ.

To start, a data acquisition (DAQ) system consists of hardware and software components designed to collect, process, and analyze data from various sources and convert it into digital format for further analysis and storage.

Components of DAQ Systems

  • Input:  Sensors (Ex: Force, Torque), Digital Signals (Ex: DIO, Counters), Timing Signals (Ex: IRIG, GPS) and Serial Streams (Ex: RS-232, RS-422)
  • Signal Conditioning Circuitry: Excitation, Amplifier, Voltage Offsets, and Filters
  • Analog-to-Digital Converters (ADC)
  • Digital-to-Analog Converters (DAC)
  • Hardware and Software for processing, analyzing, display and recording
  • Output Signal: prior to ADC, after DAC, or even after processing

Analog data acquisition systems acquire and process analog signals. Analog signals can include sensors that measure load, force, torque, strain, temperature, pressure, voltage, current, and many other physical or electrical qualities.  Digital data acquisition systems acquire and process digital signals. Digital signals can include on and off states, counters, serial streams, text data, video, GPS signals, and other advanced options.

 Key Considerations for DAQ Systems

  • Features
    • Supported range of inputs mV/V, VDC, mA, partial bridge, encoder, pulse, frequency
    • Included software and related functionality
  • Form factor
    • Bench top, rack mount, portable, ruggedized and others
  • Sample rate
  • Connectivity
  • Power supply
  • Channel count and cost per channel

Interface DAQ Products

Interface offers a range of solutions for DAQ systems. The top products for DAQ include:

During the webinar, Keith and Dave detail a series of product groups for the Interface Data AQ Packs.

Data AQ Pack Brochure

Watch the webinar and learn more about product options, software, applications and best practice tips.

Unlocking the Power of DAQ Webinar

Interface webinar Unlocking the Power of DAQ details trends, best practices and considerations for using data acquisiton in force measurement applications. We explore DAQ instrumentation options, trends and set-up options. Learn why data acquisition systems are growing in popularity for all types of use cases. We also detail the new Interface Data AQ Packs and system options for capturing critical data. Watch the online technical seminar for recommendations on equipment, plus we answser the most frequently asked questions about DAQ in test and measurement.

Testing Lab Essentials Webinar Recap

Interface recently hosted an in-depth discussion about one of our favorite topics, testing labs. Our focus in this technical webinar centered on test lab devices, instrumentation, industry testing lab challenges and considerations, along with best practices. We also took a deep dive into different testing lab applications and how to modernize your test lab.

Force measurement experts Elliot Speidell and Jeff Boyd delivered an engaging and knowledgeable seminar, Testing Lab Essentials: Today + Tomorrow.  Bringing decades of first-hand experience, they were able to provide product examples, tips, recommendations and lessons learned in working with testing lab professionals across industries, from automotive to medical devices.

Initial discussions in the event covered test lab basics, including types of products should be in every lab that performs testing of force, torque, and weight. The quick summary, force, torque and weight measurement devices including load cells and torque transducers of various models, calibration grade equipment and published standards, test stands, data acquisition systems and safety equipment.

One of the first steps in assessing any lab is the type of measurement equipment on hand to perform various testing requirements. Transducer selection criteria includes mechanical connection and load application, force magnitude and loading condition, cycle count, form factor restrictions, environmental conditions, additional measurements needs, such as multiple axis.

Testing labs often require different types of load cells depending on the type of products being tested and the applications in which the load cells will be used. Here are some common types of load cells used in testing labs:

  • Compression load cells: Used to measure the compressive force applied to an object. They are commonly used in materials testing to measure the strength of materials such as concrete, metals, and plastics.
  • Tension load cells: Used to measure the tensile force applied to an object. They are commonly used in materials testing, such as in tensile strength testing of metals and other materials.
  • Shear load cells: Used to measure the shear force applied to an object. They are commonly used in materials testing, such as in shear strength testing of materials.
  • Multi-axis load cells: These load cells are capable of measuring forces in multiple directions and are commonly used in structural testing applications.
  • Torque transducers: Used to measure torque or twisting forces. They are commonly used in automotive testing, industrial machinery, and other applications where rotational forces are important.
  • Fatigue-rated load cells: These load cells are designed to withstand high-cycle fatigue testing and are commonly used in materials testing and durability testing of products.
  • Low profile load cells: These load cells are designed to fit into tight spaces and have a low profile, making them ideal for use in small-scale applications.
  • High-capacity load cells: These load cells are designed to measure large forces and are commonly used in heavy machinery and structural testing.

Instrumentation is central to any testing lab environment. The three most common types of instrumentation found in test lab includes:

  • Indicators: Indicators are used to convert the input signal to a local displayed value.  Often they will have features like, peak capture, alarms, and analog outputs.
  • Signal Conditioners: Signal conditioners are used to convert (amplify) one type of electrical signal into another. 
  • DAQ: Data acquisition systems are used to collect and analyze data from measurement devices. These systems may include software, hardware, and data processing equipment.

In a series of follow-up InterfaceIQ Blog posts we will detail other topics covered in this information packed discussion, including modernization, load frames and test stands, do and don’t tips, plus frequently asked questions.

Watch the complete webinar here:

Data Acquisition Systems 101

Engineers and testing professionals use data acquisition systems to enable smart decisions. The data retrieved through DAQ systems empower users to identify points of failure, optimize performance, and create efficiencies in products and processes.

When it comes to measuring force, the accuracy and reliability of the sensor is a critical component to receiving quality data. The data acquired from measurement devices, including load cells, torque transducers, and other types of force sensors, is valuable for product development, research, and robust testing to ensure performance and durability of all types of innovations. Ultimately, utilizing precision-based data provides enhanced control and response for all types of applications and use cases. Interface provides a wide range of data acquisition instrumentation that is easily paired with our force measurement products.

By definition, a data acquisition system is a collection of components used to acquire data via analog signals and converting them to digital form for storage, research, and analysis. Data acquisition systems, also called DAQ systems, typically are made up of sensors, signal conditioners, converters, plus computer hardware and software for logging and analysis. Interface experts are available to help pair the transducers with the right instrumentation.

The data acquired through the measurement device is only useful if it is logged for analysis and traceability. This is where instrumentation, in particular DAQ systems come into play, in not only transferring data, but also obtaining the right type of data in a format and data transfer method that works with existing user systems.

Data acquisition that utilizes analog output has long been the standard in the industry. As new requirements for use cases and applications grow, test and measurement professionals and engineers find these systems advantageous because of the lower cost, easy integration, and scalability. They also like the advantage of daisy-chaining multiple sensors together on a single cable run to maximize the amount of data through single tests. More data improves the quality of analysis and monitoring.

Advancements in sensor technologies coincide with growing demands for digitalization and to gather more testing data. This is seen using multi-axis sensors, along with requirements for multi-channel acquisition that can integrate into existing systems already designed with specific digital connections and protocols.

In addition to improving speed of data output, acquisition systems offer an abundance of value-added benefits. This is primarily due to the digital signal, as they are less susceptible to noise and are more secure. The systems also typically have built in error detection. Digital signals are best for transmitting signals across longer distances or when you need to allow for simultaneous multi-directional transmissions. Many people like the ease of integration, both into existing networks as well as with other testing devices.

Data acquisition systems and accessories come in many shapes and sizes, wired and wireless and there are also a handful of different software options in different systems. All these various products such as digital instruments, input and output modules, cables, monitors, and accessories. Interface offers a range of DAQ products, including full systems including the sensors.

Interface Complete Data Acquisition Systems

BlueDAQ Data QA Pack

Force sensors can easily connect via the BlueDAQ Family Data AQ Pack for fast and accurate data acquisition. This solution provides a convenient way to view the test results from transducers including single axis, dual axis, 3-axis, and 6-axis multi-axis sensors. Check out our BX8-HD44 BlueDAQ Series Data Acquisition System for Multi-Axis Sensors with Lab Enclosure.

T-USB-VS Rotary Torque Transducer Data AQ Pack

Connecting dynamic torque transducers to the T-USB Rotary Torque Transducer Data Acquisition Pack will provide you with convenient way to view the test results for your torque transducers that have internal USB functionality.

WTS Wireless Data AQ Pack

Utilizing the popular WTS Wireless Data Acquisition Pack provides convenient wireless communication with speeds up to 200 samples per second. Learn more in our Interface Wireless Telemetry System Review. See the complete line Interface WTS here.

DIG-USB PC Interface Module Data AQ Pack

Interface’s DIG-USB Data Acquisition Pack enables a straightforward way to view the test results our load cells or torque transducers. Check out the popular DIG-USB Output Module and the DIG-USB-F Fast USB Output Module.

9325 Portable Display Data AQ Pack

Interface’s 9325 Data Acquisition Pack makes your system portable. The 9325 allows simple display of strain bridge based measurements such as load cells, torque transducers, and other mV/V output transducers with sensitivity up to +/-1 V/V.

INF-USB-VS3 PC Interface Module Data AQ Pack

Our INF-USB-VS3 Data Acquisition Pack connects Interface mV/V load cells or torque transducers to provide real-time data analysis.  Here is more information about the INF-USB3 Universal Serial Bus Single Channel PC Interface Module.

Interface Data Acquisition Systems are modular. We offer the complete system, including enclosures, along with single components to complete a system. Consult with our application engineers to learn what system would be best for your test and measurement programs.

Data AQ Pack Brochure

 

 

 

Digital Instrumentation 101

Digital instrumentation used for test and measurement provides faster data input and output, and more robust analytics. Interface offers several types of digital instrumentation devices that transform load cell and strain bridge input into digital data output in numerous protocols and bus formats.

Instrumentation that utilizes analog output has long been the standard in the industry. As new requirements for use cases and applications grow, test and measurement engineers and professionals find digital instrumentation advantageous because of the lower cost, easy integration and scalability. They also like the advantage of daisy-chaining multiple sensors together on a single cable run.

Advancements in sensor technologies coincide with growing demands to gather more testing data. This is seen through the use of multi-axis sensors, along with requirements for multi-channel instrumentation that can integrate into existing systems already designed with specific digital connections and protocols, as highlighted in using Interfaces BX8 with our 6-Axis sensors. Change is also coming with a strong desire to utilize instrumentation that can easily work within cable free environments or in remote locations.

In addition to improving speed of data output, digital instrumentation offers an abundance of benefits. This is primarily due to the digital signal, as they are less susceptible to noise and are more secure. Digital instrumentation typically has built in error detection. Digital signals are best for transmitting signals across longer distances or when you need to allow for simultaneous multi-directional transmissions. Many people like the ease of integration, both into existing networks as well as with other testing devices.

Types of Interface Digital Instrumentation

  • Indicators and Bidirectional Indicators
  • Portable and Programmable Indicators
  • Battery Powered Indicators and Bidirectional Indicators
  • Single and Multi-Channel Transmitters
  • Controllers and Programmable Controllers
  • USB Output Modules
  • PC Interface Modules
  • Sensor to USB Output Converters
  • Data Acquisition Systems
  • Wireless Instrumentation

Connection options available for Interface Digital Instrumentation include, RS232, RS485, RS422, Wi-Fi, USB, Bluetooth, and Ethernet Protocols. The types of data output protocols available include ASCII, Modbus, CANopen, DeviceNet, Profibus DP Modbus/TCP, Ethernet TCP/IP, Ethernet/IP, EtherCAT and several others. See the complete list of connections and protocols in our Digital Instrumentation Overview.

Top selling digital instrumentation models from Interface, with many available in various protocols:

Do you have questions about the type of instrumentation that will support your application?  You can see more of the solutions by visiting our instrumentation selection guide.  Here are six questions begin evaluating your instrumentation options:

  • Where are you going to connect your sensor technology and how?
  • Do you need to store your data?
  • Do you prefer an analog or digital output device?
  • Are you going to plug-in your instrumentation or use hand-held, wireless or Bluetooth connectivity?
  • How will your data output be displayed?
  • How many channels do you need for your project or program?

For additional help with instrumentation, please contact our application engineers.

ADDITIONAL RESOURCES

Digital Instrumentation for Force Measurement

Ultimate BlueDAQ Software Guide for Interface Instrumentation

Interface Instrumentation Definitions

Instrumentation Selection Guide

Advancements in Instrumentation Webinar

Interface Instructional on Instrumentation Event

Instrumentation

Interface Instrumentation Definitions

The new Interface Instrumentation Selection Guide is a great way to get started in choosing the right instrumentation for your next project or lab. To serve as additional resources, here are key instrumentation definitions that can also help you make the best decision regarding the type and model of instrumentation that will work best with your sensor.

Instrumentation Selection Guide Definitions

Excitation
A Wheatstone bridge-based sensor, such as a load cell, requires excitation voltage to operate. The excitation voltage is typically 10V; however, many instruments supply lower voltage, an 2.5V, 5V, and others. Since these sensors are ratiometric, Interface instrumentation devices are designed to pair with these types of sensor products.

Signals
The output signal from a load cell is expressed in terms of mV output per V of excitation, at capacity. For example, a 100 lb capacity load cell rated for 2 mV/V output will have 20mV output at 100 lb, when excited with 10V. Because the output signal is directly affected by input voltage, it’s important to maintain a stable excitation voltage, which our instrumentation does.

Signal Conditioners
A signal condition provides stable excitation voltage to the sensor and amplifies the low-level sensor signal to a high-level output such as +/-5V, +/-10V, 0-20mA, 4-20mA, 0-5V, or 0-10V.
Many of our products include filtering, which can help reduce noise in the output signal.

Data Acquisition Systems
A complete data acquisition system consists of DAQ hardware, sensors and actuators, signal conditioning hardware, and a computer running DAQ software. Interface provides DAQ instrumentation that are ideal for completing a sensor-based system. Many data acquisition systems require high-level inputs such as +/-10V and don’t work very well with low level mV signals. Interface instrumentation solutions do work well with DAQ systems. The DAQ doesn’t necessarily supply a stable excitation voltage like the Interface sensors do.

Interface Modules
An interface module converts the low-level mV/V sensor signal to a digital format that can be transmitted to a computer, (PC or laptop). Popular interface modules provide USB, wireless USB, or Bluetooth data transmission. Software is normally provided and allows data display, logging and graphing. The interface modules are commonly used when data needs to be logged to computer and you are not using an existing data acquisition system. The interface module advantages over standard data acquisition is ease of use and they are normally plug-n-play. Considerations when selecting this type of instrumentation include bit resolution, number of channels, sample rate, software features and type of output.

Indicators
Interface indicators provide stable excitation voltage and converts the sensor signal to a digital display. Commonly available features include analog or digital output, selectable digital filtering, peak and valley monitoring and set point outputs. Things to consider when selecting an indicator are internal sample rate and update rate of analog output.

Wireless Telemetry System (WTS)
Wireless is very popular today. Interface’s Wireless Telemetry System is easy-to-use providing wireless data communication between a load sensor and a receiving indicator. The WTS is capable of receiving multiple inputs and is fully compatible will all Interface force sensors. The WTS comes calibrated, tested and ready-to-run. The charge lasts up to three months using AA batteries.  You can see the complete WTS and Bluetooth Telemetry System comparison here.

When selecting the type of instrumentation you need to pair with your measurement device, some additional things to consider are power supply requirements, amount of filtering, fixed or adjustable filtering, input range, scalability and zero adjustment range. Our instrumentation can accommodate these requirements. To get started on picking the instrumentation solution that fits your requirements, go to the Interface Instrumentation Selection Guide.

We’ve provided a quick visual reference of Interface’s instrumentation types and correlating models.

All Interface Instrumentation product details are listed by product model name. You can find product specifications, as well supporting datasheet for each product by going here.

 

Additional Resources

Instrumentation Analog Versus Digital Outputs

Introducing New Interface Instrumentation Selection Guide

Advancements in Instrumentation Webinar Recap

Recap of Inventive Multi-Axis and Instrumentation Webinar

Recap of Instructional on Instrumentation Webinar

Digital Instrumentation Brochure

Instrumentation Brochure

 

Interface Sensors Used for Development and Testing of Surgical Robotics

Electro-mechanical and software advancements in the medical device and healthcare industry have made all kinds of surgical robotics a reality. Manufacturers and design engineers of these robots come to Interface during the stages of research and development, product engineering and refinement, and testing to perfect surgical use cases. The sensor technologies we provide are preferred in these processes and in final integration due to the fact these devices are highly regulated and require the utmost in accuracy and reliability.

The types of surgeries currently being performed with robotics include what were once considered invasive and a higher risk of failure such as coronary bypass, removing cancer tissue, transplants, laser incisions, and more. With surgical robotics, the medical professionals rely on precision to perform these surgeries with as minimal invasion as possible.

The product development process for surgical robotics is extremely meticulous and requires a wide variety of tests to confirm the accuracy of the product. One of the key components to testing in this field is force measurement. As you can imagine, force plays a massive role in surgical robotics. Every action performed needs to be forced tested to ensure that whatever the surgical task, the robot is doing it with precision.

For surgical robotics, minute forces need to be measured because they are working with highly fragile subjects within a human body. To measure these tiny forces, Interface offers a variety of Interface Mini™ Solutions.  Interface Mini Load Cells are used for light touch, light weight, or for less space. Our miniature load cells provide exceedingly accurate measurements similar to our full-size load cells with proprietary alloy strain gages. They are used in R&D, test and for OEM use in robot components.

All our miniature beam load cells, load cell load buttons, load washer, miniature tension force load cells, S-type load cells, and sealed stainless steel load cells are commonly used based on their capacity and designs.  A variety of our load cells can be used in an off-the-shelf application. Our engineers can also work with you to design custom load cells to fit your exact needs, which is common in robotics.

Interface recently developed an application note to outline how force measurement can be used in testing force feedback using a combination of load cells, torque transducer and data acquisition device on a robotic surgical device.

Robotic Surgery Force Feedback

A biomechanical medical company wanted to test the force, torque, and tactile feedback from their robotic arm for invasive surgery. The surgeon’s movements are mirrored by the robotic arm during surgery, and it was essential all haptic force feedback is measured to ensure safety during invasive surgery. A number of Interface’s force and torque measurement products were suggested for this robotic arm. These includes our load button, S-types, Mini overload protected torque transducers and DAQ instrumentation.  Included below are the roles of each device:

Each one of Interface’s load cells or torque transducers played a part in the ensuring the safety and functionality of robotic arms during invasive surgery. The force feedback that was measured from the robotic arm ensured that the robot used the perfect amount of force when using surgical tools that create incisions during surgeries. It also measured the torque being produced, ensuring the robot arm was moving smoothly and at the right speeds. Read the application note for this surgical robot here.

This is just one example of Interface’s work in robotics, and surgical robotics specifically. There are a growing number of devices used in special, precision surgeries that utilize force to perform its task.

Additional Resources Related to Medical, Healthcare and Robotics

Spotlighting Medical Device and Healthcare Solutions

Medical and Healthcare Brochure

OEM: Medical Bag Weighing

Force Solutions for Medical Tablet Forming Machines

Interface OEM Solutions Process

6-Axis Force Plate Robotic Arm App Note

Force Measurement Solutions for Advanced Manufacturing Robotics

Instrumentation Analog Versus Digital Outputs

Interface sells a wide variety of instruments designed to help take data measured on a load cell or torque transducer and convert it into a readable form. Within this expanding family of instrumentation offered by Interface, there are two types of output methods available: analog or digital.

By far, analog output for test and measurement instrumentation has been the most popular. Analog output is measurement represented in a continuous stream. Technologies have advanced a growing demand for more advanced data capture. Digital instrumentation uses digits as the output, providing greater measurement accuracy and digital resolution.

Understanding which output is best for your project is important in getting the right communication capabilities to use with the designated sensor components. It’s an important consideration whether you are designing a new testing system or working with an existing program and looking to add new instrumentation.  You can gain further insights by watching our Instructional on Instrumentation webinar here.

Here is a brief explanation on the difference between analog and digital instrumentation, along with advantages of each.

Benefits of Digital

Digital outputs are becoming more and more popular for several reasons. The first is that they often incur lower installation costs than their analog counterpart. Digital also works across existing networks. For instance, if you have ethernet IP you can interface directly into it as opposed to running analog signals.

Digital outputs are also far more scalable than analog because a lot of the time you can replace sensors without causing a disruption. Multiple sensors can also be daisy chained into a single cable run, meaning the user can piggyback into an existing network rather than running cables back to a controller. This is one reasons the installation cost is often lower.

There are also built-in error detections with digital outputs to detect things like open legs and bridges. And if you’re digitizing at the sensor, the system is less susceptible to noise because digital signals are natural noise immune.

Benefits of Analog

With all the benefits of digital, why would someone still choose the older output method of analog? Analog signals are still faster than digital and are much easier to work with. Additionally, analog systems take up far less bandwidth than digital. Therefore, if you’re in an area with low-bandwidth, digital output solutions may slow the network down, while analog will not.

It is important to note that many DAQs and PLCs accept analog signals, so if the user wants to stay with what they already have in house, analog may be the better option.

Choosing Analog or Digital

When deciding between analog and digital instrumentation output capabilities, it’s important to consider the following questions as well:

  • Are you connecting to an existing network? For instance, if its CAN bus, you may want to use CAN bus sensors. But, if it’s pure analog, you’re not going to want to convert everything over to digital unless there are other factors driving this move?
  • Are you connecting to an existing DAQ device? If your system has available analog input channels, you may be fine with analog output. If it doesn’t, you may have to add extra channels. Or say the system has an EtherCAT connection, you can use the same DAQ without adding channels by interfacing with it digitally.
  • What is your budget? If your network already has a lot of analog systems, the cost of staying with analog may be worth it. If you must add channels to your DAQ, but you have digital interfaces available, that may allow for cost savings based on how many channels and sensors you need.
  • How many sensors are you connecting? If you have a lot of sensors, the obvious answer is digital because of the flexibility it provides, and the limited cable runs needed. But if you don’t need many sensors, analog could make more sense.

There are several considerations to make when choosing digital versus analog.  You can learn more about which options suit your project requirements by reviewing the online specs of our range of instrumentation solutions.

There is also considerable detail in the many options available in our Instrumentation Overview here.

Additional Instrumentation InterfaceIQ Posts

Instrumentation Options in Test and Measurement

Instrumentation Application Notes

Force Measurement Instrumentation 101

Digital Instrumentation for Force Measurement