How to Apply a Strain Gage

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Last Updated: February 13, 2026

Recording the amount of strain applied to a sample of material is a common test performed by engineers. By understanding how much strain is applied by a certain force, engineers can predict the strength and viability of that material for their purposes. To read the strain occurring within a test sample, a strain gage is utilized. This article will instruct you how to apply a strain gage to a test bar.

Part 1

Part 1 of 3:

Preparing the sample

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You will need all the items pictured here. Some items may vary by manufacturer from those pictured.
It's best to do this on a level and clean surface.

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Use a patch of abrasive material such as sandpaper.
Spray the bar with CSM-3 degreaser and wipe with a gauze sponge.
Identify where you will be applying the strain gage on the bar. Apply a few drops of M-prep conditioner and wipe away with a gauze sponge.
Use a straightedge and pencil to mark a horizontal line across the width of the test bar where you will be applying the strain gage. This will be used later to make sure the gage is perfectly centered on the bar.
Pour a few drops of M-prep neutralizer onto the pencil mark you have just made.
Use a cotton tipped applicator to rub the mark away from the test bar. This will leave behind a visible line on the surface but removes any contaminates that may prevent sticking.

Part 2

Part 2 of 3:

Applying the gage

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Use a piece of scotch tape to gently pick up the gage and position it on the test bar so it bisects the line you created. Do not fully paste the tape and gage to the bar! Pull back the tape so that the sticky side and the bottom of the gage are facing up.
Brush a careful amount of the catalyst onto the surface of the gage.
Place a few drops of M-bond 200 adhesive onto the surface of the bar where the gage will stick.
Press down firmly on the strain gage and hold for about thirty seconds to ensure it stays in place.
The strain gage should remain secured to the bar, but if it comes free, place the gage again and retry the applying process.

Part 3

Part 3 of 3:

Wiring the gage

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Allow the iron time to warm up.
Carefully hold the wire against the solder until it solidifies.
Tape the wire down to the test bar so that it remains secure. If your wire becomes disconnected from the gage, just remelt the solder and allow it to solidify again.
It is advised that you seek the device's instructions. If your device reads strain when it is applied to the test bar, you have successfully installed a strain gage.