In order for a strain gauge to deliver an accurate measurement, it must be properly installed onto the measuring object. This white paper will help you choose the correct adhesive and how to properly apply it to the object. It will also help explain the differences among adhesives, how to prepare a surface for bonding, and provide tips for when installing the strain gauge.

Adhesives 101: Sticking to the point

As the most common way to bond strain gauges to the measurement object, an adhesive must be suitably high quality to ensure complete transfer of the strain from the measurement object into the strain gauges. If you “lose” some of the strain in the bond between the object and the strain gauge, you will have errors in your measurement.

To help ensure comprehensive transfer of the strain from the measurement object into the strain gauges, you must choose the right adhesive for your object and then install the gauge properly.

Understanding adhesive options

To achieve the most precise measurement, you will want to choose the best adhesive for your object and application. To do so, it helps to understand the options available to you.

Single versus multi component adhesives

  • Single-component adhesives are ready to use out of the tube and do not require mixing components.
  • Multi-component adhesives usually have two components that must be mixed before use. These adhesives also have a “pot lifetime,” meaning a time range in which you can use the adhesive after mixing—it can be for minutes or hours.

Cold versus hot-curing adhesives

  • Cold-curing adhesives only need to be room temperature to install the strain gauge on the object.
  • Hot-curing adhesives must be heated while curing. However, that means that the object must be able to fit into an oven and withstand hotter temperatures while the adhesive cures. You also must have a way to apply and hold pressure on the strain gauge while the object is in the oven. Because these adhesives are heated in the curing process, they can withstand hotter operating temperatures. They are often used in transducer manufacturing.

Curing time

Different adhesives require varying curing times in order to harden. Curing times in part depend on the environment temperature. If it’s colder, adhesives take longer to cure. Where temperatures are warmer, adhesives cure more quickly.

Operating temperature

Different adhesives are designed to withstand different environmental temperatures. An adhesive’s data sheet will specify its operating temperature range. If you use the object and strain gauge outside of the specified operating temperature, it can introduce errors into the strain measurement. For example, if an adhesive is approved to operate in environments up to 200°C, using it in an environment over 200°C will soften the adhesive into a creamy consistency and negatively affect the strain measurement.

Beyond temperature, some adhesives also have humidity parameters.


Adhesives are made with differing viscosities because certain object materials perform better with either low or high viscosity adhesives.

  • Thin adhesives glue the strain gauge to the object without requiring a thick layer of substance for a secure bond. Generally, thin adhesives are better because a thick layer adds distance between the object and gauge, which will skew a strain reading. This misreading can be exacerbated if you’re using a bending strain gauge, which relies on a neutral layer on your object as a base for measurement.
  • Thick adhesives are better for porous objects. For example, thin adhesives are simply absorbed into concrete, which requires a thicker, pastier adhesive. However, you should still try to use as thin of a layer as possible.

For more about choosing an adhesive, read our TechNote, "Selecting adhesives for strain gauge installation".

HBM adhesives

HBM offers a broad range of adhesives for different purposes. Here is a snapshot of our offerings.

Z-70 — A fast-acting superglue that is the standard adhesive for experimental stress analysis

  • Single component
  • Cold curing (room temperature)
  • One-minute curing time with only thumb pressure
  • Operating temperature is -55°C to 100°C for static measurement (meaning the zero point is very important). The adhesive can withstand up to 120°C for dynamic measurement. Humidity must be above 30 percent.
  • Low viscosity (thin adhesive)

X60—Methacrylate mixture

  • Multi component—a two-component adhesive comprising a powder and a liquid
  • Cold curing (room temperature)
  • Two- to five-minute curing time
  • Operating temperature is -200°C to 80°C for dynamic measurements
  • High viscosity (thick adhesive)—65 micrometer layer

X280—An Epoxy resin

  • Multi component—two components in easy-mix bags
  • Hot or cold curing with defined pressure
  • Eight hours curing time at room temperature; one hour curing time heated to 95°C
  • Operating temperature is up to 200°C for static measurements; 280°C for dynamic measurements
  • High viscosity (thick adhesive)—40 micrometer layer

EP150—An Epoxy resin

  • Single component
  • Hot curing
  • Six hours curing time at 160°C; one hour at 190°C
  • Operating temperature is up to 150°C
  • Low viscosity; often used for transducer manufacturing

EP310S—An Epoxy resin

  • Multi-component—one month pot life
  • Hot curing
  • Thirty minute curing time at 200°C; 6 hours for transducer manufacturing at 120°C
  • Operating temperature is -270°C up to 310°C for dynamic measurement
  • Low viscosity; often used for transducer manufacturing


An accelerator for the superglue, Z70, can be used to accelerate the curing of the adhesive to compensate for low humidity. Note: The accelerator works very quickly, so the first attempt at applying the strain gauge must be precise. Some engineers will simply blow on the adhesive to add humidity rather than attempt using an accelerator.

Learn about other HBM strain gauge products at

How to prepare an object’s surface for an adhesive

It's very important that you create a clean surface for bonding the strain gauge to the object. If dirt, grease, paint, rust or other finishes are left on your object, the bonding will not be effective. First, use scrapers or grinders to clean the surface of any materials that may prevent the strain gauge from adhering directly to the object.

The second step in cleaning the surface is to smooth it out, so that it can be properly cleaned of debris that may have been created from the scraping or grinding. Finally, you will want to use a cleaning solvent, such as HBM’s RMS1, which is specifically designed to prepare surfaces for bonding.

Note: To ensure that there is no oxide layer present where you want to install your strain gauge, you must clean the object shortly before applying the adhesive and strain gauge. If you cannot immediately apply the strain gauge after cleaning, adhesive tape can protect the surface from oxygen and dust for a short time.

Once the surface is thoroughly clean, you will want to roughen the object’s surface, which will improve bonding power by increasing the active surface area. You can use sand blasting or emery paper with 180 to 300 grain size, depending on your adhesive. The adhesive’s data sheet should identify the recommended grain size. Next, you will want to clean the surface one last time. It is important not to skip this step as it is possible dirt was rubbed into the measurement spot during the roughening process.

Tips for readying specific object materials for the adhesive

The quality of the strain gauge installation has direct effect on the margin of measurement error in the reading. Here are some surface preparation tips for specific materials.


In general, metals—such as aluminum, copper-beryllium, copper and steel—are easy to prepare with standard cleaning and roughening. Typically, you can use any of the adhesives previously discussed.

It is easy to use adhesive on metals, with few exceptions. With titanium, you have to work quickly to apply the strain gauge because the adhesive can create oxide layers on the metal.



Instead of preparing plastics with abrasion-based roughening, you may opt for chemical roughening with Tetra-Etch. You can also apply oxygen plasma on polyethylene using a handheld applicator. Not all adhesives work on plastics, so be sure to read the data sheets of the adhesives after you have narrowed down your choices

Installing the strain gauge

With your surface cleaned, roughened and cleaned again, you are ready to start installing your strain gauge with your adhesive of choice. First, you mark on the surface where you would like to apply the strain gauge on the measuring point of the object. Use an empty ball point pen to mark the surface without leaving ink, which would only need to be removed.

Do not:

  • Use a sharp needle to scratch the surface. It will damage the components.
  • Touch the surface. Even clean fingers will leave behind some amount of oil and grease, which will negatively affect the bonding.
  • Blow on the surface. Breath will add moisture and attract contaminants.

Once the surface is marked, it is ready for a final cleaning. Use the RMS1 degreaser or a similar product with a clean, lint-free, cellulose cleaning pad to remove any last traces of grease. Rub with the cleaning pad until there are no traces of contaminants left on it. Always use a new pad for each cleaning, and never pour excess degreaser back in to the bottle.

Now you are ready to install the strain gauge. HBM strain gauges are pre-cleaned and ready to apply to an object. Remove it from the package using tweezers (do not touch it with your fingers) and place it on the mark you made with the empty pen on your clean surface. Use adhesive tape to cover the connections and keep it in position while you prepare the adhesive. You can also use adhesive tape to protect the object from adhesive glue once you apply it. Simply place the tape around the strain gauge as if it were a border. This tape will protect the object from adhesive. 


Read the instructions for your chosen adhesive, and mix it if it’s a multi-component adhesive. When the adhesive is ready, remove the tape with tweezers and lift the strain gauge, also with tweezers, and apply a thin layer of adhesive on the mark. Set the gauge back down on the adhesive and apply steady, even pressure. You don’t want the strain gauge to move once you set it on the adhesive.

After you have applied the strain gauge and the adhesive is cured, remove the tape border with tweezers. Continue to apply pressure to the gauge. Be sure not to remove the tape in the middle of curing. 

If you are using a fast-curing adhesive and only using your thumb to add pressure, be sure to use Teflon foil between your thumb and the strain gauge so you don’t accidentally glue your thumb to the gauge.

For more information

By choosing the right adhesive for your application and installing your strain gauge properly, you can minimize measurement errors and improve accuracy of your strain gauge.

Click here for more information about adhesives, strain gauge installation, and experimental stress analysis.

About the author

Jens Boersch has been with HBM for 14 years as a product manager. He has worked with nearly all products—including strain gauges, amplifier systems and data acquisition software—in the test and measurement world of HBM. He is based in Darmstadt, Germany.

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