Optical Strain Sensors Fundamentals

Optical strain sensors, namely those based on Fiber Bragg Grating (FBG) technology, have been gaining increased attention particularly in the field of infrastructure monitoring over the past decades. But just how does an optical sensor work? How do I compensate for optical losses? How many sensors can be integrated into one single fiber? Our experts dug deep to provide their best answers for you about all the important questions regarding strain measurement using fiber optical sensors. Click an option below to direct you to the content on the page.

  1. Basics of Strain Measurements and FBG Technology
  2. Selecting the Right Strain Sensor, Adhesive and Accessories
  3. Installation of Optical Sensors: All there is to Know
  4. Applications of Optical Strain Sensors: Looking Beyond
  5. Reduction and Elimination of Measurement Errors 
  6. Acquiring Data with the Right Hardware and Software 
  7. Free Training on Optical Strain Measurements

1. Basics of Optical Strain Measurements and FBG Technology

What is a fiber Bragg grating

Fiber Bragg gratings are just a few millimeters long, highly sensitive and very reliable. These sensors are easy to install, immune to electromagnetic interferences and can also be used in highly explosive atmospheres. Learn more about their properties here.

How does a fiber optical strain gauge work

“When people need to measure strain, they first think of electrical strain gauges. Optical strain gauges can come in handy, though, where electrical ones won’t work, for example due to environmental conditions” , says Cristina Barbosa, Product Manager at HBM FiberSensing. To learn more, click here.

Common questions on FBG technology & systems

How is strain measured? Is strain measurement sensitive to temperature? What is the maximum distance an optical fiber line can achieve? If you are looking for quick and uncomplicated answers to these and other questions on measuring with light, check out our practical on-line faqs page here.

The reference white paper on strain measurements using FBG sensors

Get a complete overview of the topic of "Strain measurements with Fiber Bragg Grating sensors" - Manfred Kreuzer's reference paper. This paper gives a short introduction to FBG sensors, points out their special strengths and weaknesses and describes a measuring system which enables strain gauges and FBGs to be measured simultaneously...

ePaper available here

2. Selecting the Right Strain Sensor, Adhesives and Accessories

How to select the right optical strain sensor

HBM offers two lines of optical strain sensors based on Fiber Bragg Grating (FBG) technology that are suitable for almost every measuring task. But how do you find the right strain sensor? Here you will get the complete information to help you find the most suitable strain sensor gauge or sensor for your needs.

How to select the right adhesive

Optical strain sensors can be applied to the surface of the object to be measured using adhesives. Here you can learn which adhesive should be used when gluing an optical strain sensor and tips for preparing a measuring point that ensures good bonding for strain transfer.

How to improve the optical measurements

The quality of measurement with strain sensors essentially depends on the type of installation and design of the measuring point. A thorough preparation of the installation surface, correct connection and slicing are important factors for obtaining problem-free results. Check HBM range of easy-to-set-up accessories here.

3. Installation of Optical Strain Sensors: All There is to Know

How to prepare material for a strain gauge installation

Click here for a quick overview of how you can prepare your material for effective strain sensor installation. By applying the suggestions provided by our highly-skilled experts, you can achieve successful installation on concrete, plastics, fiber-reinforced material, among others.

How to weld a strain gauge

Some environments are not suitable for bonding of strain gauges owing to very low temperatures or excessive dust formation, e.g., at construction sites. Weldable strain gauges are the best choice for being used in these kinds of environments. Watch our video on how to weld your strain gauge correctly.  


Tips for installing strain gauges

In many cases, measuring the strain on an object is done within a short timeframe. If the strain gauge is improperly installed, false measurements can be obtained. Watch this video to learn how to install gauges in the most effective way.


4. Applications of Optical Strain Sensors: Looking Beyond

Infrastructures monitoring with optical sensing systems

Optical technologies and sensors come across as a viable and promising option to meet the challenges of monitoring a structure's health, such as large sensing networks and hazardous environments. Find out more here.

The potential of optical sensors for condition monitoring

Condition Monitoring Systems (CMS) are designed to ensure the long-term efficiency of many components on structures such as wind power plants. The focus moves here to optical sensor technology as an alternative to electrical technology.

Optical fiber sensors vs. conventional electrical strain gauges for infrastructure monitoring

Get a complete overview of the topic of "Optical Fiber Sensors vs. Conventional Electrical Strain Gauges for Infrastructure Monitoring Applications".

ePaper available here

Successful case studies and references using optical FBG sensors

Get access to all the success stories regarding the use of optical strain sensors in a wide scope of measurement applications and monitoring projects undertaken by HBM. Just select Optical FBG Sensors in the dropdown list under Type of Sensors Used here.

5. Reduction and Elimination of Measurement Errors

Measurement uncertainty: Less errors, better results

There are certain possible sources of error when strain gauges are used for experimental stress analysis. Learn how to successfully assess measurement uncertainty already in the design stage by clicking on the title above.

Temperature effects on measurement results

Unwanted temperature effects can affect the measurement results while using strain gauges. Find practical assistance on how to minimize these effects or compensate for them entirely. Learn more by clicking on the title above. 

6. Acquiring Data with the Right Hardware and Software

How to configure optical strain sensors in BraggMONITOR SI

In this tutorial you will learn how to acquire strain measurements from optical sensors using HBM's BraggMONITOR SI data acquisition software and FS22 BraggMETER SI (static) interrogator. The Smart Peak Detection feature allows accurate and stable detection of all FBG peak values in large/complex sensing structures.


7. Free Training on Optical Strain Measurements

Recorded webinars

Missed one of our live webinars? Watch our recorded webinars on optical strain measurements and sensors. Use the filter to select the ones that best suits your needs.