Use Image J software

you can download it from the website:

http://rsb.info.nih.gov/ij/

link:

https://imagej.nih.gov/ij/download.html

You can try an ImageJ. This is freeware software. Having scale bar in a SEM image, you can calibrate the whole image and then directly measure any features in the SEM image.

Best regards,

Andriy

Use Image J software

you can download it from the website:

http://rsb.info.nih.gov/ij/

link:

https://imagej.nih.gov/ij/download.html

At newest SEM operating software include an option that allows to measure objects sizes directly on monitor. So, try to find it on your device.

ImageJ .... freeware

Greetings,

Filippo

Image J is easy to calibrate and measure the crack lengths